93 Ford Taurus GL 3.0 Liter V6 with Intermittent Rough Idle Problem
caliwolf
to discovering what's causing it.
I have a 93 Ford Taurus GL with a problem with rough idling (to the
point of stalling if gas is not applied to keep it at a high enough
speed) and, of course, stalling. The problem has persisted after I've
changed the fuel pump and fuel filter, the EGR valve, the Idle Air
Control Valve and the spark plug cables. Code readouts point all over
the place, if the car generates codes at all. Codes, when they are
logged, point to a vacuum issue. The rough idle problem does not
always start first thing.
In the mornings, I can sometimes run the car halfway to work before it
misses a lick. Sometimes it can go all day and not miss a beat. And
then there are some days I don't get out of the driveway.
There is a whistle when the engine is idling in the driveway but, in
the location I hear the whistling, there are no vacuum hoses to be
seen. So, if there is a vacuum leak, I can't locate it. Not only
can't I locate it, it is beyond intermittent.
Performed a leak test around the intake manifold and there was no
leaking there. I have even cleaned the carbon from the butterfly valve
on the intake and it has not helped the problem any.
I'm nearing my wits end here and, if I take it into a mechanic, I'd
like to point to something more specific than 'it has an intermittent
problem, possibly related to the vacuum'. Any ideas or help that you
can offere would be most appreciated.
Backyard Mechanic
> This issue has baffled me for over a month now and I am still no closer
> to discovering what's causing it.
>
> I have a 93 Ford Taurus GL with a problem with rough idling (to the
> point of stalling if gas is not applied to keep it at a high enough
> speed) and, of course, stalling. The problem has persisted after I've
> changed the fuel pump and fuel filter, the EGR valve, the Idle Air
> Control Valve and the spark plug cables. Code readouts point all over
> the place, if the car generates codes at all. Codes, when they are
> logged, point to a vacuum issue. The rough idle problem does not
> always start first thing.
>
It would be nice if we knew the specific codes you read out. Never let
Autozone tell you what they think the codes mean,
and
never ask for tech advice by telling the person you're consulting what
YOU think the codes mean.
The PRIMARY function of the Idle Control Valve is to keep the engine
running by giving it enough air.
If it dies from low idle, it's not working right... and vacuum leaks
result in a HIGH idle.
It's quite possible your new one is defective.. or you have a bad
connection in the wiring betwen it and the PCM.
If you also had certain shifting problems, I'd suggest changing the TPS.
For some reason EECIV doesnt tell you if that sensor is flaky.
I would pull the connectors for the IAC, TPS (probably okay to just
change the TPS), etc and check for corrosion.. clean them and lube them
with dielectric grease. Also check the engine to body ground and the
harness ground near the PcM.
--
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
Mortimer Schnerd, RN
> There is a whistle when the engine is idling in the driveway but, in
> the location I hear the whistling, there are no vacuum hoses to be
> seen. So, if there is a vacuum leak, I can't locate it. Not only
> can't I locate it, it is beyond intermittent.
If there's not a vacuum line there, perhaps there should be? There should be a
sticker with a graphic of the vacuum lines under the hood somewhere; I know
there is on both of my Tauruses (Tauri?). I'd make sure you can account for all
of them.
> I'm nearing my wits end here and, if I take it into a mechanic, I'd
> like to point to something more specific than 'it has an intermittent
> problem, possibly related to the vacuum'. Any ideas or help that you
> can offere would be most appreciated.
Personally, I'm reluctant to offer opinions on what a mechanic *should do* when
I bring a car in for service. He may very willingly perform the procedure I've
outlined, knowing full well that I'm just wrong. All it does is run my bill up.
You may end up better off to tell him just the symptoms and mention that you
hear a new hiss as well. Let him figure it out. If you don't trust him to do
that, why are you there?
--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com
caliwolf
> It would be nice if we knew the specific codes you read out. Never let
> Autozone tell you what they think the codes mean,
> and
> never ask for tech advice by telling the person you're consulting what
> YOU think the codes mean.
These are the codes that the car produced yesterday on the drive into
work (the first time the check engine light has come on and stayed on
since we began putzing with the car with its current problem):
558 EGR Vacuum Regulator CKT (EVR)
565 Canister Purge CKT Fault
652 Modulated Lockup Solenoid CKT
157 MAF signal too low
211 PIP Erratic
332 EGR valve no opening (EVP/PFE/DPFE)
And these codes were read off of the Snap-On Code Reader that was
borrowed from a mechanic friend up at work. Hope the codes are helpful
and thank you very much for your suggestions.
Bob Urz
As a old taurus owner, i will suggest a few things:
Vacuum hoses. they tend to rot and leak. start with the hoses on the
passenger side of the engine. Look closely for cracks. replace ALL hoses
that look suspicious. there is a hose that plugs into a plastic hose
that goes down to the front drivers side radiator area then turns into a
rubber hose again (goes to purge). check the hoses in this area and
replace as needed. Some of these hoses are hidden and have covers over
them so so sleuthing is needed.
change the plug wires. clean in MAF sensor and clean out the IAT.
change the fuel filter and air filter. Rescan and see where your at.
Bob
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caliwolf
The issue is really more of a low idle than a rough one. Gas has to be
applied, the idle gets so low. It becomes slobbery but I believe
that's because of low idle.
While running down the highway, the engine 'surges', that is goes up
and down in tone, as if the computer is trying to compensate for
something.
Now, the car itself will crank and put out no spark; no spark from the
plugs. It will not start at all. It put out the following fault
codes, similar to the ones before:
564 Fan Control Fault
558 EGR Vacuum Regulator (EVR) Fault
565 Canister Purge Circuit Fault
652 Modulated Lockup Solenoid Circuit
625 Electronic Pressure Control Open.
It just keeps getting better and better....
Backyard Mechanic
> Now, the car itself will crank and put out no spark; no spark from the
> plugs. It will not start at all. It put out the following fault
> codes, similar to the ones before:
>
> 564 Fan Control Fault
> 558 EGR Vacuum Regulator (EVR) Fault
> 565 Canister Purge Circuit Fault
> 652 Modulated Lockup Solenoid Circuit
> 625 Electronic Pressure Control Open.
>
> It just keeps getting better and better....
>
You have a serious PCM power problem.
Tha explains why the idle is low... and so many differnt ckt faults; not
enough power to drive those various soleoids, etc.
Start checking all the engine and harness grounds and the CCRM {relay
module}
lhasaluvers
I have just got about the same problem with mu 93 Taurus 3.0. When I
first start it it will idle rough and stall. If I get it in drive or
reverse right away, it smooths out and will run great. I used my Sunpro
code scanner for it and got the following codes.
*Code 53.TPI (Throttle Position Sensor)*
*Voltage too high.*
*Code 95 TAC (Thermactor Air System) *
*Problem on right side air flow always upstream.*
*or FPM (Fuel Pump Monitor)*
*Indicates circuit problems.*
*Code 3 EGO (Exhaust Gas Oxygen) sensor*
*No switching (Right Side0
I was blaming the EGR but it might be another sensor. My stepson and I
are going to check it with his big computer tomorrow. He's not sure it
is the EGR valve too. I will post our findings here later.
*
In the mornings, I can sometimes run the car halfway to work before it
misses a lick. Sometimes it can go all day and not miss a beat. And
then there are some days I don't get out of the driveway.
There is a whistle when the engine is idling in the driveway but, in
the location I hear the whistling, there are no vacuum hoses to be
seen. So, if there is a vacuum leak, I can't locate it. Not only
can't I locate it, it is beyond intermittent.
Performed a leak test around the intake manifold and there was no
leaking there. I have even cleaned the carbon from the butterfly valve
on the intake and it has not helped the problem any.
I'm nearing my wits end here and, if I take it into a mechanic, I'd
like to point to something more specific than 'it has an intermittent
problem, possibly related to the vacuum'. Any ideas or help that you
can offere would be most appreciated.
--
lhasaluvers
Message origin: TRAVEL.com
lhasaluvers
I have the same problem with my 93 Taurus. Have run my Sunpro code
scanner on it and it comes up with.
*Code 53.TPI (Throttle Position Sensor)*
*Voltage too high.*
*Code 95 TAC (Thermactor Air System) *
*Problem on right side air flow always upstream.*
*or FPM (Fuel Pump Monitor)*
*Indicates circuit problems.*
*Code 3 EGO (Exhaust Gas Oxygen) sensor*
*No switching (Right Side0
it tomorrow. He thinks it might just be a sensor controling the EGR
valve.
*
lhasaluvers
After getting all the different codes, my stepson decided to check out
the Air Bypass Valve. He found that it was stuck in a half open
position. We replaced the ABV and the car ran perfect. Ran code check
again and had none. Another thing that was happening when the ABV was
bad was the headlights would dim when you applied the brakes. It was
solved also by replacing the ABV. I'm sure glad I didn't replace all
the other parts that the codes indicated that were bad before checking
the ABV. I hope this information helps others. I know I was going batty
for a while.*
Wes
similar issues with my '06 Ranger (3.0L V6) a couple years back and it
turned out to be the same thing... sorry about that.
If it's not too late, don't throw the old one out, they can often be
cleaned up and used again. BTW, the dim headlights when applying the
brake was likely the engine revs dropping so low with the idle all
screwed up that the alternator was no longer turning fast enough keep up
(oh, and Ford actually call the "ABV" an "Idle Air Control Valve").
I hope that you appropriately rewarded your step son for saving the day!