3.0 wont idle but runs great
Steve
will run all day long, runs great, but at the end of the day, it refuses to
idle, it just dies on me. Start it back up and it will run full throttle
just fine, but try to idle and it dies. If I let it sit for a day or two, it
goes back to running normal.
So far I have rebuilt the carb, rebuilt the fuel pump, cleaned the fuel
filter. checked for water in the gas, put another ingnition module in,
replaced the coil. Im out of things to do.
What am I missing?
Thanks
Steve
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jamesgangnc
Did you try premium? Sounds like maybe it is vapor locking.
Steve
out all the jets with the carb cleaner in the can. I dont think its vapor
lock, I can see gas squirt out the accel pump jets.
Keep throwing guesses. cuz I have no clue.
Is it possible that the flapper valve is bouncing around in the exhuast tube
?
Thank you sofar
Steve
<gfre...@aol.com> wrote in message
news:n23m17hkl69i19gq9...@4ax.com...
> Are you sure you got the idle jet passages cleaned out?
JR North
JR
Steve wrote:
--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth
Steve
<gfre...@aol.com> wrote in message
news:1irm17d26ent9vgq1...@4ax.com...
> On Mon, 11 Jul 2011 13:52:21 -0700, JR North
> <junkjas...@bigfoot.com> wrote:
>
>>Carb base insulator possibly missing?
>>JR
>
> Yup or maybe a vacuum leak, bad base gasket or a leak somewhere else.
>
> Try dribbling gas down the carb throat with a small squeeze bottle and
> see if it idles (fast).
>
> You can listen for a vacuum leak with a piece of small hose. Hold one
> end up to your ear and probe with the other. It helps to stick a ball
> point pen barrel or other small tube on the probe end so you can
> control it better..
I_am_Tosk
gfre...@aol.com says...
> >JR
>
>
> Try dribbling gas down the carb throat with a small squeeze bottle and
> see if it idles (fast).
>
> You can listen for a vacuum leak with a piece of small hose. Hold one
> end up to your ear and probe with the other. It helps to stick a ball
> point pen barrel or other small tube on the probe end so you can
> control it better..
You can also get something like Cyclo brand Carb cleaner (or other
volatile spray. DO NOT USE STARTING FLUID. Spray it around the hoses and
junctions and see if any of them makes the engine rev up or changes the
rpm. Be careful not to get fooled by putting it in the air cleaner;) But
it's a quick way to find a vacuum leak...
--
Team Rowdy Mouse, Banned from the Mall for life!
I_am_Tosk
youstol...@clear.net says...
I don't know if you have a four stroke or a two, but if it only happens
when it's hot, how about (4 stroke) if you have a valve that's
stretching and bottoms out on the bucket when it's hot?
They tighten up when they get hot... on a four stroke..;)
If it's a two stroke, Do a compression test or a leak down test, then
check the reeds??? Do two stroke boat engines have reed valves, I
suppose they must...
Just thinking out loud, something is happening when it gets hot, I am
thinking you are loosing compression when it's hot or some kind of mild
blow by that doesn't effect the engine at higher rpm based on the ratio
of leak, to mixture delivered to the cylinder...
Tim
You might want to run a compression test to see if you have a burnt
valve. My 140 would sort of do the same thing, but would run WO and
pull the proverbial "4000 RPM", and there was no sign of water in the
oil, but when idling back down it would cough, and die. it took some
throttle work to get it over the dead spot but would seem to run fine.
however, pulling a tube was a chore. a real loss of power. but w/o the
extra drag, you couldn't tell it.Under investigation it had a blown
head gasket and two exhaust valves burnt.
Had the head checked out, replaced with all steel valves and a new
gasket
Runs great and hasn't stalled since.
I_am_Tosk
@d14g2000yqb.googlegroups.com>, tsch...@gmail.com says...
Yup, that's what I am thinkin'...
Tim
> In article <d9767c46-043d-4627-83df-cf4287ca83b7
Yeah, Scott. I think his problem is'nt fuel delivery, but much deeper
than that.
Steve
I started it last night, ran fine.
It seems to do this only when it has below 1/2 tank. and after idleing for a
while (over 10 minutes) SOOOO ????
Its in a Balyliner 175,year:2005.
A couple of ideas that I want to throw out there .
Is there a screen in the fuel pick up?, I already checked the gas tank vent,
clear.
Could the ignition module be funky, gets hot and retards the timing?
I really dont want this one, can a bad flapper/shutter cause it,
Thanks again. Sorry for the mindtwist
Steve
"Tim" <tsch...@gmail.com> wrote in message
news:7ebaaeb1-cfdb-4744...@u28g2000yqf.googlegroups.com...
--- Posted via news://freenews.netfront.net/ - Complaints to ne...@netfront.net ---
Tim
> my compression gauge only goes to 160. I pegged the gauge on each cylinder.
> I started it last night, ran fine.
> It seems to do this only when it has below 1/2 tank. and after idleing for a
> while (over 10 minutes) SOOOO ????
> Its in a Balyliner 175,year:2005.
> A couple of ideas that I want to throw out there .
> Is there a screen in the fuel pick up?, I already checked the gas tank vent,
> clear.
> Could the ignition module be funky, gets hot and retards the timing?
> I really dont want this one, can a bad flapper/shutter cause it,
> Thanks again. Sorry for the mindtwist
Steve, I see you're much ahead of the game. did you try a different
ignition coil?
jamesgangnc
>
> - Show quoted text -
Might help if you guys read the orginal post. He's got a 3.0l merc.
That's an inboard 4 cylinder 4 stroke chevy.
TopBassDog
Might help to understand I have one just like it in an '83 Chris Craft
169 Scorpion.
What'd you think we were talking about man, a Port-Huron Steam engine?
TopBassDog
I am fascinated that a small reciprocating engine can give such
hassles.
jamesgangnc
>
> - Show quoted text -
That was directed at the suggestion he might have reed valve problems.
jamesgangnc
> my compression gauge only goes to 160. I pegged the gauge on each cylinder.
> I started it last night, ran fine.
> It seems to do this only when it has below 1/2 tank. and after idleing for a
> while (over 10 minutes) SOOOO ????
> Its in a Balyliner 175,year:2005.
> A couple of ideas that I want to throw out there .
> Is there a screen in the fuel pick up?, I already checked the gas tank vent,
> clear.
> Could the ignition module be funky, gets hot and retards the timing?
> I really dont want this one, can a bad flapper/shutter cause it,
> Thanks again. Sorry for the mindtwist
>
> - Show quoted text -
Running at higher throttle takes more gas so it seems unlikely that a
fuel system clog would be the problem. You could put a fuel pressure
guage on it while running to see. My tank pickup has no screen but
that probably varies from boat to boat. Most cheap vacuum guages are
also fuel pressure guages.
The valve problem suggestion is not unreasonable. Normally there is
enough clearance in the valve train so that after it gets hot and
expands the valves still close fully. But if the valves are staying
slightly open that can create the symptom you have. It's usually the
exhaust valves. You should be able to test for this by doing a
compression test with the engine hot. Failure of the valves to close
fully when hot will eventually lead to burnt exhaust valves. They can
be checked with a feeler gauge. They are not adjustable but different
length pushrods are available. I suspect you could convert to
adjustable with studs and locking valve nuts.
Vapor lock sometimes cause this problem but often will clear up with a
little running at higher throttle as that fills the fuel system with
cooler gas from the tank. Sounds like you engine never resumes normal
idling after it gets hot. Vapor lock can be mitigated with a thick
carb spacer. Sometimes the routing of the metal fuel line form the
pump to the carb needs to be changed as well. Builders often did not
consider the issue of ethanol which makes vapor lock more common.
Modern cars don't have a problem because their fuel systems run at a
much higher pressure these days.
As another poster suggested dribbling gas down the carb throat with a
squeeze bulb might help you tell if it is simply not getting any gas
at all at idle. It's pretty tricky to get that just right. I've done
the same thing with starter fluid. Just get in a rythm of giving it a
quick shot every few seconds. I'd have a fire extingusher handy if
you're going to try these experiments.
The coil is a common cause but it normally fails at any rpm when hot
and resumes working after cooling. Besides you replaced the coil.
You mentioned module advance but I thought you had tried a different
module? You can check the timing when hot with a timing light. I
know it will be tricky when it won't idle. Have someone back the
throttle down and watch the mark come back around as the rpm drops.
You should see it get close to normal just before the engine stops
turning completely. I find it helps to put a dab of paint on the
balancer where the idle timing is supposed to be.
How hot does it get? Do you believe you have an accurate temp guage?
Maybe it's hotter than you think. Know anyone with a infrared temp
gun? The ones the hvac guys use.
I_am_Tosk
youstol...@clear.net says...
Well, a compression test is great if the symptoms are happening when
it's cold and you do the test, but in the case of a smoked valve, it can
happen only when it gets hot (for now)... I could be wrong but I think
for the valves, you need to do a leak down test, and even then if the
valve isn't hanging open cold, it won't show you much...
I_am_Tosk
@n35g2000yqf.googlegroups.com>, james...@gmail.com says...
We read the origional post.... LAST WEEK!!! And I don't know a 3.01 merc
from a Evenrude outboard. So, you are the mechanic, what do you think?
jamesgangnc
wrote:
> In article <ivh466$2oe...@adenine.netfront.net>,
> youstolemyb...@clear.net says...
>
>
>
>
>
>
>
> > my compression gauge only goes to 160. I pegged the gauge on each cylinder.
> > I started it last night, ran fine.
> > It seems to do this only when it has below 1/2 tank. and after idleing for a
> > while (over 10 minutes) SOOOO ????
> > Its in a Balyliner 175,year:2005.
> > A couple of ideas that I want to throw out there .
> > Is there a screen in the fuel pick up?, I already checked the gas tank vent,
> > clear.
> > Could the ignition module be funky, gets hot and retards the timing?
> > I really dont want this one, can a bad flapper/shutter cause it,
> > Thanks again. Sorry for the mindtwist
> > Steve
>
> Well, a compression test is great if the symptoms are happening when
> it's cold and you do the test, but in the case of a smoked valve, it can
> happen only when it gets hot (for now)... I could be wrong but I think
> for the valves, you need to do a leak down test, and even then if the
> valve isn't hanging open cold, it won't show you much...
>
> --
>
> - Show quoted text -
You can do a compression test when it's hot and if the valves are not
closing it will show a lower pressure. And it won't hold pressure
nearly as well.
To differentiate between valve problems and ring problems you squirt
in a little oil before testing. Oil will improve low compression from
bad rings but not from bad valves.
I think he has gas problems though, not valve issues. If the valves
were staying open it would also cause hard starting when hot.
And it's a merc 3.0l not a 3.01. Which stands for 3.0 liters. That
is a 4 cylinder inline chevy engine that's been around for a long
time. You will find them and the 2.5l in all sorts of stuff besides
boats. You won't get a ton power out of one but they are very
reliable as a rule. I believe the volvo 3.0l is based on the same
engine. Not to be confused with Mercs 4 cylinder "half of a ford
cobrajet" engine.
Steve
"jamesgangnc" <james...@gmail.com> wrote in message
news:2fc36cb3-4f52-4d4f...@hd10g2000vbb.googlegroups.com...
OK let me start over, It is the Chevy 3.0 litre engine.(4 stroke) alpha gen
II outdrive. a 2005 to be exact.
Symptoms: Will run great all day, when it gets to a half tank or at the end
of the day, it will start and run fine, but when it idles for longer than 10
minutes, it will die. Then after it dies, it is VERY hard to start and will
only stay running at over 2k rpm. go back to it in a day or so, it runs fine
Things I have done so far
Rebuilt the carb
Rebuilt the fuelpump
cleaned the plugs and distributor cap ( got to wait till payday for those
items)
put a different coil on it
tried a different ignition module
compression check= over 160psi each
checked the timing (with module grounded according to the book)
checked the tank vent (clear)
verified spark at each plug
The engine never gets real hot, Im lazy and never took the time to remove
the rock that is stuck in my thermostat that prevents it from closing.
Im wondering if maybe I have a busted exhaust shutter. I noticed that where
the manifold and the down elbow meet that there is a line of rust going down
the maniflold, but it does not leak. I am super anal retentive about this
boat and know that I drained it last fall. Is it possible that part of the
shutter is bouncing around in the exhaust tube, getting lodged in it at
times, hit a wake and it bounces free?
Thanks for all the help so far
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jamesgangnc
> "jamesgangnc" <jamesgan...@gmail.com> wrote in message
>
> - Show quoted text -
I'm rather sceptical about the internal exhaust flaps. Blocking the
exhaust will cause it to run poorly at low speed and not at all at
high rpm. But the flaps are usually fairly easy to examine. If you
remove the elbow that turns down from the riser the flaps should be
just below that in the tube going down towards the outdrive.
You suggested that it may have a relationship to the amount of gas you
have left. Test that theory. Be near a marina with fuel when you
start to get around half a tank. When it acts up go fill it up. No
marina then put several 5 gallon cans of gas in the back of your truck
and be near the dock when it acts up.
You also said it goes away when it has cooled for days. Was that
without filling the tank back up? Instead let it cool for just an
hour or so and see if the problem goes away.
Does the engine have a regular cover on it or is it under a sundeck?
You could try leaving the engine open by leaving off the cover for a
day. If the problem is eventual heat soak into something that would
delay that.
I also suggested checking the compression when hot as well as checking
the fuel pressure when it is acting up. Plus you can check the timing
when it's acting up without grounding the ignition module. Just note
the deg at idle and at 2k rpm when the engiine is not acting up
without grounding it. Then check them again when it is.
jamesgangnc
>
> - Show quoted text -
Btw, your symptoms sound very much like vapor lock brought on by the
eventual heat soak of the general engine compartment area. Leaving
the cover off all day would be a good test for that.
Florida Jim
Exhaust shutters usually get very noisy. once in a while they break and
fall to the bottom of the exhaust pipe. No biggie. Needs fixing but it
isn't your problem.
You need to clear or replace the thermostat. Running cool leads to poor
gas mileage plug fouling and or carbon buildup ( excessively high
compression).
Also part of the ignition is the trigger in the distributor. They
probably fail more often than the ECM.
Boating All Out
youstol...@clear.net says...
>
>
> OK let me start over, It is the Chevy 3.0 litre engine.(4 stroke) alpha gen
> II outdrive. a 2005 to be exact.
> Symptoms: Will run great all day, when it gets to a half tank or at the end
> of the day, it will start and run fine, but when it idles for longer than 10
> minutes, it will die. Then after it dies, it is VERY hard to start and will
> only stay running at over 2k rpm. go back to it in a day or so, it runs fine
Runs great all day. So it's not a heat/electrics problem.
Half tank it gives problems.
That means a bad fuel pump or bad tank venting.
Check fuel pressure at full tank and at half tank.
Simple.
Harryk
As long as everyone is giving wild-assed guesses...
distributor problems or...if it has one, idle air solenoid...
Harryk
says...
Spoofer! I took many mechanical engineering courses, and I know
everything. I wouldn't have to guess at the problem.
John H
Bad tank venting. I hadn't seen that yet, but it sounds like it could be the problem. Create a
vacuum and you've got a problem.
Good 'eyes'.
Florida Jim
Steve
since sunday. Started right up. So i be thinking...
What about the internals of the distributor, can a pick up coil go bad?
Can I use a igntion module from a car to test it again? Does anyone test
ignition modules?
Thanks
Steve
"Florida Jim" <no...@jose.net> wrote in message
news:4e1dd25c$0$9782$c3e8da3$1cbc...@news.astraweb.com...
--- Posted via news://freenews.netfront.net/ - Complaints to ne...@netfront.net ---
Wayne B
wrote:
>Can I use a igntion module from a car to test it again? Does anyone test
>ignition modules?
===
Usually it is easiest to swap one out with a module known to be good.
Have you tested fuel pressure yet at the carburetor ?
Florida Jim
replace the trigger wheel too, since it may get damaged upon removal to
get at the module. One more thing. Have you checked the coil high
tension lead? If it's resistor wire it should read 1 or 2 K ohms
otherwise 0 ohms.
jamesgangnc
> Well its not a pinhole in the pickup tube. Have started or seen the boat
> since sunday. Started right up. So i be thinking...
> What about the internals of the distributor, can a pick up coil go bad?
> Can I use a igntion module from a car to test it again? Does anyone test
> ignition modules?
> Thanks
> Steve"Florida Jim" <no...@jose.net> wrote in message
>
> news:4e1dd25c$0$9782$c3e8da3$1cbc...@news.astraweb.com...
>
>
>
>
>
> > On 7/13/2011 1:04 PM, John H wrote:
> >> On Wed, 13 Jul 2011 11:07:38 -0500, Boating All Out<boa...@boating.com>
> >> wrote:
>
> >>> youstolemyb...@clear.net says...
>
> >>>> OK let me start over, It is the Chevy 3.0 litre engine.(4 stroke) alpha
> >>>> gen
> >>>> II outdrive. a 2005 to be exact.
> >>>> Symptoms: Will run great all day, when it gets to a half tank or at
> >>>> the end
> >>>> of the day, it will start and run fine, but when it idles for longer
> >>>> than 10
> >>>> minutes, it will die. Then after it dies, it is VERY hard to start and
> >>>> will
> >>>> only stay running at over 2k rpm. go back to it in a day or so, it runs
> >>>> fine
> >>> Runs great all day. So it's not a heat/electrics problem.
> >>> Half tank it gives problems.
> >>> That means a bad fuel pump or bad tank venting.
> >>> Check fuel pressure at full tank and at half tank.
> >>> Simple.
> >> Bad tank venting. I hadn't seen that yet, but it sounds like it could be
> >> the problem. Create a
> >> vacuum and you've got a problem.
>
> >> Good 'eyes'.
> > Another guess. Pin holes in pickup tube in gas tank.
>
>
> - Show quoted text -
Electronics affected by heat very seldom operates partially. If the
trigger sensor in the distributor or the ignition module is failing
when hot it would be a lot more likely to fail completely. Then work
again when cooled.
You said you tried a known good module? What happened then?
The merc ignition components are pretty reliable.
Steve
I took the boat out yesturday and beat the hell out of it, It ran fine. This
is whats driving me nuts. I hate intermittent problems. I did replace the
coil with a known good one, I am going to check the old coil to see if it is
within spec this weekend
Thanks
Stevenews:c8a81dfc-db2b-4f2a...@e21g2000vbz.googlegroups.com...
--- Posted via news://freenews.netfront.net/ - Complaints to ne...@netfront.net ---
jamesgangnc
> The module I used was from a car. It worked fine.
> I took the boat out yesturday and beat the hell out of it, It ran fine. This
> is whats driving me nuts. I hate intermittent problems. I did replace the
> coil with a known good one, I am going to check the old coil to see if it is
> within spec this weekend
> Thanks
From a car? How did you manage to get a car electronic ignition to
work on a merc? Not saying it can't be done but why?
jamesgangnc
> On Fri, 15 Jul 2011 05:24:15 -0700 (PDT), jamesgangnc
> marinized parts where they might spark. (alternators starters etc)- Hide quoted text -
>
> - Show quoted text -
Yes, but the trigger and the trigger module are generally designed to
work as a pair. And on boats there is no vacuum advance and often no
mechanical advance either. All the advance is handled by the module.
On cars the vacuum advance was used because the engine load is not
consistent like it is on a boat. Then all of that changed completely
when cars went to computerized spark controls. Could you make a car
one from the era when cars still had them work, sure. But it's not
just going to plug in to the thunderbolt connector.
jamesgangnc
> On Fri, 15 Jul 2011 10:41:07 -0700 (PDT), jamesgangnc
>
>
>
>
>
> <jamesgan...@gmail.com> wrote:
> >On Jul 15, 12:54 pm, gfretw...@aol.com wrote:
> >> On Fri, 15 Jul 2011 05:24:15 -0700 (PDT), jamesgangnc
>
> >> >work on a merc? Not saying it can't be done but why?
>
> >> Why not. These I/Os are basically just auto/truck engines with
> >> marinized parts where they might spark. (alternators starters etc)- Hide quoted text -
>
> >> - Show quoted text -
>
> >Yes, but the trigger and the trigger module are generally designed to
> >work as a pair. And on boats there is no vacuum advance and often no
> >mechanical advance either. All the advance is handled by the module.
> >On cars the vacuum advance was used because the engine load is not
> >consistent like it is on a boat. Then all of that changed completely
> >when cars went to computerized spark controls. Could you make a car
> >one from the era when cars still had them work, sure. But it's not
> >just going to plug in to the thunderbolt connector.
>
>
> - Show quoted text -
And I was asking how exactly he did that. He said he used a car
module. Well the only ignition module I know of that plugs into the
merc harness is the merc thunderbolt one. And you won't get the merc
one off a car. So I wanted more details. No matter why he did it I
don't understand how he did it.
Steve
all gm igntions systems. Remember this is a 2005 with the electronic
iginition.
There is no mechanical advance or vacuum advance. it is all done in the
module.. As far as the coil goes, I looked up the numbers off the coil, same
coil (different mount) as a coil off of a 1987-1994 gm blazer or anything
with the 4.3 v6 OR the small block V8
"jamesgangnc" <james...@gmail.com> wrote in message
news:9fdca589-cc63-4a1f...@x10g2000vbl.googlegroups.com...
--- Posted via news://freenews.netfront.net/ - Complaints to ne...@netfront.net ---
jamesgangnc
> I looked up the numbers on the module, its the same module that is used on
> all gm igntions systems. Remember this is a 2005 with the electronic
> iginition.
> There is no mechanical advance or vacuum advance. it is all done in the
> module.. As far as the coil goes, I looked up the numbers off the coil, same
> coil (different mount) as a coil off of a 1987-1994 gm blazer or anything
> with the 4.3 v6 OR the small block V8
>
>
> - Show quoted text -
Yes, I realized it was electronic ignition. Merc has had electronic
ignition for a pretty long time. Since late 80s I think. I didn't
know they had started switching over to gm modules, for a long time
they made their own thunderbolt module. The early automotive modules
still relied on vacuum advance to detect when the engine was under a
load at low rpm. Today on cars the computer controls everything and
most cars now have gone to individual coil/module packs per spark
plug.
I still would put the electronics at the bottom of my list. Heat
associated failure of electronics is generally always total failure
until it cools back down.
I still suspect heat soak of something though. Did you try leaving
the engine cover off for a day to see if that delays or eliminates the
problem?
Steve
What about the antisiphon valve?
Thanks
Stevenews:34362fd0-238d-4142...@d7g2000vbv.googlegroups.com...
--- Posted via news://freenews.netfront.net/ - Complaints to ne...@netfront.net ---
I_am_Tosk
youstol...@clear.net says...
Still wondering what it takes to check the valve lash on these things...
Florida Jim
jamesgangnc
> > youstolemyb...@clear.net says...
> >> engine cover off, no go. started acting up again.
> >> What about the antisiphon valve?
> >> Thanks
> >> Steve
> > Still wondering what it takes to check the valve lash on these things...
>
>
> - Show quoted text -
True that. Non-adjustable as well.
I_am_Tosk
a1d405...@v12g2000vby.googlegroups.com>, james...@gmail.com
says...
Oooops...
Florida Jim
assume you removed the pickup tube and inspected it for a clogged screen
or pin holes? You can eliminate the vent by leaving the gas cap loose.
Collapsing rubber fuel lines are sometimes hard to detect; especially if
the hose has delaminated.
If you have a spin on fuel filter, you can remove it when the engine
stalls and see if it's full of gas. You can dump the gas from the filter
into a glass container and see if it's contaminated with sediment or
water. The fuel system fittings up to the fuel pump must be air tight or
you won't get good suction. Did you weigh the float in the carb. and
check the float level adjustment? Did you replace the carb. inlet
filter? Is your flame arrestor clean? If the metal fuel line runs to
close to the hot engine you can put a bit of insulation on it. The
thermostat must be functioning for the engine to run properly. Did you
fix it? Is the choke operating properly. Electrically you have the
ignition module, trigger module, coil, coil tower lead, and neutral
safety switch. The manual might have some test procedures, otherwise
it's swap them out. Most of this has been said before but you still have
a problem. You need to go back to square one and start over.
Good luck.
jamesgangnc
> On 7/19/2011 6:25 AM, Steve wrote:
>
>
>
> > engine cover off, no go. started acting up again.
> > What about the antisiphon valve?
> > Thanks
> > Steve
>
> You can visually inspect that. It's just a ball and spring. Can we
> assume you removed the pickup tube and inspected it for a clogged screen
> or pin holes? You can eliminate the vent by leaving the gas cap loose.
> Collapsing rubber fuel lines are sometimes hard to detect; especially if
> the hose has delaminated.
> If you have a spin on fuel filter, you can remove it when the engine
> stalls and see if it's full of gas. You can dump the gas from the filter
> into a glass container and see if it's contaminated with sediment or
> water. The fuel system fittings up to the fuel pump must be air tight or
> you won't get good suction. Did you weigh the float in the carb. and
> check the float level adjustment? Did you replace the carb. inlet
> filter? Is your flame arrestor clean? If the metal fuel line runs to
> close to the hot engine you can put a bit of insulation on it. The
> thermostat must be functioning for the engine to run properly. Did you
> fix it? Is the choke operating properly. Electrically you have the
> ignition module, trigger module, coil, coil tower lead, and neutral
> safety switch. The manual might have some test procedures, otherwise
> it's swap them out. Most of this has been said before but you still have
> a problem. You need to go back to square one and start over.
>
> - Show quoted text -
He's got a rather specific symptom that points to the most likely
cause being a heat issue. It runs fine for a good part of the day and
then starts failing to idle. But still runs ok at higher rpms.
Starting it the next day before adding more gas and it idles fine.
He's already replaced or rebuilt a lot of stuff with no effect on this
problem.
I suggested multiple times he use it for a day with the engine cover
off.
Florida Jim
doors open for consideration.
John H
Y'all must've missed this.
>>>> engine cover off, no go. started acting up again.
>>>> What about the antisiphon valve?
>>>> Thanks
>>>> Steve
It was top posted.
jamesgangnc
>
> - Show quoted text -
Yep, I did miss that.
Califbill
news:MPG.288f44934...@news.eternal-september.org...
Oooops...
Reply:
Collapsed lifter?
iainwa...@gmail.com
> Hey all, I have a 2005 3.0l mercruiser sterndrive that is acting wierd. It
> will run all day long, runs great, but at the end of the day, it refuses to
> idle, it just dies on me. Start it back up and it will run full throttle
> just fine, but try to idle and it dies. If I let it sit for a day or two, it
> goes back to running normal.
> So far I have rebuilt the carb, rebuilt the fuel pump, cleaned the fuel
> filter. checked for water in the gas, put another ingnition module in,
> replaced the coil. Im out of things to do.
> What am I missing?
> Thanks
> Steve
>
>
>
> --- Posted via news://freenews.netfront.net/ - Complaints to ne...@netfront.net ---
Well, sounds very similar to an issue I have at the moment.... so breaking it down
1. Forget the shutter. if it can be traced to "Only" when the engine is hot, then forget this.
2. Same with the electronic ignition components.. i.e. if it is going to fail, you will not be running at any RPM let alone high speeds.
3. Valves... here is one possibility; either adjusted too tight causing them (or at least one of them)to remain slightly open when the components are hot, then returning to running fine when cool again. Add this to cylinder head work having been done, and you have a strong possibility. Before you get all down and deep on compression analysis, try adjusting them to spec.
4. Carb, yes, possibly if you have dirt,water etc floating around in the system, but you mentioned that you had cleaned the system, and I assume you didn't just mean the carb, so unlikely.
5. Cyl head gasket, again unlikely if it is only happening while hot. One point to mention here though: if you are replacing a head gasket I recommend the use of Blue Hylomar (this will take care of any imperfections).
6. Thermostat, unlikely since you have not mentioned any association with excessive temp.
7. Impeller, again unlikely since you have not mentioned any association with excessive temp.
8. So, now to one obscure possibility, assuming all else is good..... tank vacuum; is your fuel tank breathing properly? or is it under vacuum after running a while. I only say this in case your valves are found to be fine. If the breather in your tank is blocked/restricted it will lead you to believe the issue is due to your engine being hot, when in fact it is just down to the running time (fuel consumption/hr) and nothing at all to do with temperature (Since you have not mentioned "High" temp, I am going to assume again the temp is fine). This situation will only show itself after the engine has been performing, so no use trying to sit at the jetty all day trying to troubleshoot, it Must be under load (i.e. using plenty of fuel). again like the valves, once it has been left for some time the situation returns to normal.
So, to summarise; you have 2 possibilities left:
VALVES, OR FUEL TANK.
Justan Olphart
temp low or high. I think you would notice a tank vacuum problem while
running under load.
Califbill
them. Depending on the carb, if the needles are a little sticky.
gfre...@aol.com
wrote:
>I would pull the idle jets and make sure they are clean and no detritus in
>them. Depending on the carb, if the needles are a little sticky.
the way, back out them out several turns (one at a time) then rev up
the motor and cover the carb throat. The momentary high vacuum would
suck the crap out most of the time. Of course if the passages are
plugged, that may not work.
Califbill
screw up the low speed jet.
gfre...@aol.com
wrote:
pretty recently boats used carbs similar to what you would see in a 67
Chevy because there was no real emission control.
Poquito Loco
>On Monday, July 11, 2011 at 11:02:13 AM UTC+1, Steve wrote:
>> Hey all, I have a 2005 3.0l mercruiser sterndrive that is acting wierd. It
>> will run all day long, runs great, but at the end of the day, it refuses to
>> idle, it just dies on me. Start it back up and it will run full throttle
>> just fine, but try to idle and it dies. If I let it sit for a day or two, it
>> goes back to running normal.
>> So far I have rebuilt the carb, rebuilt the fuel pump, cleaned the fuel
>> filter. checked for water in the gas, put another ingnition module in,
>> replaced the coil. Im out of things to do.
>> What am I missing?
>> Thanks
>> Steve
>>
Tim
Anyone notice the date on this original post? "
I like it. Same with Philip and his oars.
I like that one too!
Poquito Loco
gfre...@aol.com
some of these internet portals since so many people will just start a
new question on an old thread.
Poquito Loco
search in the google group to see if their question's already been asked.
gfre...@aol.com
much attention to the date either. If they do not quote the original
note, you may not even know. I purge the database frequently so I
can't go too far back.
Justan Olphart
Justan Olphart
water. Most of us know who they are. ;-)
Justan Olphart
Poquito Loco
https://groups.google.com/forum/?hl=en#!topic/rec.boats/Mi-RufFKphw
Date is on the right.
lynn...@gmail.com
> Hey all, I have a 2005 3.0l mercruiser sterndrive that is acting wierd. It
> will run all day long, runs great, but at the end of the day, it refuses to
> idle, it just dies on me. Start it back up and it will run full throttle
> just fine, but try to idle and it dies. If I let it sit for a day or two, it
> goes back to running normal.
> So far I have rebuilt the carb, rebuilt the fuel pump, cleaned the fuel
> filter. checked for water in the gas, put another ingnition module in,
> replaced the coil. Im out of things to do.
> What am I missing?
> Thanks
> Steve
>
>
>
gfre...@aol.com
Take out the idle screw. Don't lose the spring. Shoot generous amounts
of carb cleaner in the hole. Reassemble and back out the screws about
2-3 turns. Start the motor rev it up and slam your hand over the
intake a few times to create max vacuum and dislodge what the carb
cleaner broke loose. Readjust normally and see if it is not better
(usually 1/12 turns out is a starting point).
If this is EFI, look for an idle air solenoid valve.
toddom...@gmail.com
Todd
Bill
gfre...@aol.com
That sounds like a carb problem to me. If it was an outboard I might
have other ideas but this is basically a car that doesn't idle.
If this has idle screws, Back them out 2 or 3 turns, crank it up and
with it turning 2500 RPM or so, slam your hand over the carb throat.
The high vacuum and rich mix *might* suck the crap on through. Then
run them back in and back out to the starting point (usually 1 1/2
turns) and adjust from there.
Bill
jet when I took the carb apart. Added a good filter just before the carb.
Jets are so tiny, that the least bit of detritus plugs them.