1994 VW Jetta III cranks and won't start

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bi...@scn.org

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Jun 4, 2007, 6:51:54 PM6/4/07
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two weeks ago, on my way from from work, my jetta was losing coolant
due to broken hose, got overheated and stalled right after i had
parked it. now it will crank but won't start.

i first checked oil and coolant and there's no sign of blew head
gasket, checked all the fuses and replaced distributor cap & rotor and
spark plugs. the spark plugs wires have good continuity. i also
checked the timing belt and it's is in good condition and has correct
timing.

still no go

all the relays are clicking when ignition key is switched to on. the
ignition coil has primary resistance of 0.6 Ohm and secondary
resistance of 3400 Ohm and 12V output with the ignition key on.
according to haynes manual, they are within specs.

a strong smell of gas is present in the cabin when engine is cranking,
but spark plugs are dried and there's no sparks at the distributor.

and i noticed that the shift indicator in the dash board won't change
accordingly to the gear shift. and the string that looks like "1n 02"
is flashing in place of the odometer when the key turned to ON.

i spent the last two weekends fixing it to no avail

any idea will be greatly appreciated.

oh it's a jetta III GL model with 4 cyl 2.0L ABA FI engine

dave AKA vwdoc1

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Jun 4, 2007, 9:31:10 PM6/4/07
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<bi...@scn.org> wrote in message
news:1180997514.0...@m36g2000hse.googlegroups.com...


> two weeks ago, on my way from from work, my jetta was losing coolant
> due to broken hose, got overheated and stalled right after i had
> parked it. now it will crank but won't start.

Where was this broken hose?
How could you tell there was no sign of a blown head gasket?

> i first checked oil and coolant and there's no sign of blew head
> gasket, checked all the fuses and replaced distributor cap & rotor and
> spark plugs. the spark plugs wires have good continuity. i also
> checked the timing belt and it's is in good condition and has correct
> timing.
>
> still no go

Possibly:
Ign switch
Ign coil
Engine Speed Sensor
Faulty main engine wiring harness plug or connections wet.

>
> all the relays are clicking when ignition key is switched to on. the
> ignition coil has primary resistance of 0.6 Ohm and secondary
> resistance of 3400 Ohm and 12V output with the ignition key on.
> according to haynes manual, they are within specs.

Bentley manual would be more informative. ;-)
Try to start engine using a remote starter and leave the ign switched on.
MAKE SURE IT IS IN PARK OR NEUTRAL!!!

>
> a strong smell of gas is present in the cabin when engine is cranking,
> but spark plugs are dried and there's no sparks at the distributor.

Hmmm you smell gas but the plugs are not wet? That smell has to come from
somewhere. Maybe you have a fuel leak......but you should still get a
spark. This sounds like another problem that should be addressed.


> and i noticed that the shift indicator in the dash board won't change
> accordingly to the gear shift. and the string that looks like "1n 02"
> is flashing in place of the odometer when the key turned to ON.

Dash Gear Shift Indicator is not functioning??? I would examine any
electrical plugs on the auto trans and engine that might have had a shower
of coolant!

"1n 02" is Normal....after so many miles those service indicators will come
on and need to be reset after servicing. ;-)

--
later,
dave
(One out of many daves)


bi...@scn.org

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Jun 6, 2007, 12:06:57 PM6/6/07
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On Jun 4, 9:31 pm, "dave AKA vwdoc1" <vwd...@hotmail.com> wrote:
> REPLIES WITHIN
>
> <b...@scn.org> wrote in message


hi dave,

thanks so much for the reply

the hose connecting the reservoir and the engine block was broken, a
small breech near the connector, but the engine did have a good shower
of coolant.. last time it stalled, it was when i tried to wash the
running engine at the car wash, took about half an hour to start and
run again, this time seems no hope :(

i fixed the hose, intentionally dumped more coolant and was happy to
see no traces of oil, so i guess the head gasket is ok.. i filled the
coolant up and wiped off the excess, and waited a few days for the
engine to dry then came back and changed the plugs, dist. cap and
rotor..

yeah i did remote started the car, i used a 8 gauge copper wire to
jumper the starter's solenoid to battery ( + ) terminal, ignition key
in ON position, gear in NEUTRAL, same thing, cranks but won't run, at
least i can conclude that the ign switch is OK

i then touched the fuel injectors while cranking the engine and they
are not responsive.. actually i have no idea how the injectors would
"wiggle" when they are working, at the intake manifold inlet i smelled
only a faint odor of gasoline

i cleaned all electrical connectors with CRC cleaner and so far
evrything seems fine but no sparks, no injectors pulses

yeah haynes manual sucks.. i googled for information and narrowed the
problems down to the coolant temp sensor, the camshaft sensor, the
engine speed sensor and the ECU

my car has a distributor so i guess the engine speed sensor is only
for RPM and the ECU wouldn't cut off ignition when it's gone bad, a
bad camshaft sensor maybe the cause, but then i thought the coolant
sensor got the most damages during engine overheating and i cringed
when i thought that maybe the ECU is dead too..

my question is would a faulty coolant sensor cause the ECU to abandon
ignition and injection? a safety measure perhaps?
oh and i dont see the check engine light coming on when the ign key is
ON and prior to cranking... and the OEM alarm wouldnt go off when i
reconnect the ( - ) terminal... my ECU is dead?

dave AKA vwdoc1

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Jun 6, 2007, 10:49:32 PM6/6/07
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<bi...@scn.org> wrote in message
news:1181146017....@q75g2000hsh.googlegroups.com...


>
> thanks so much for the reply
>
> the hose connecting the reservoir and the engine block was broken, a
> small breech near the connector, but the engine did have a good shower
> of coolant.. last time it stalled, it was when i tried to wash the
> running engine at the car wash, took about half an hour to start and
> run again, this time seems no hope :(
>
> i fixed the hose, intentionally dumped more coolant and was happy to
> see no traces of oil, so i guess the head gasket is ok.. i filled the
> coolant up and wiped off the excess, and waited a few days for the
> engine to dry then came back and changed the plugs, dist. cap and
> rotor..
>
> yeah i did remote started the car, i used a 8 gauge copper wire to
> jumper the starter's solenoid to battery ( + ) terminal, ignition key
> in ON position, gear in NEUTRAL, same thing, cranks but won't run, at
> least i can conclude that the ign switch is OK

Sounds good

> i then touched the fuel injectors while cranking the engine and they
> are not responsive.. actually i have no idea how the injectors would
> "wiggle" when they are working, at the intake manifold inlet i smelled
> only a faint odor of gasoline

They might click when working and should be working while cranking the
engine over.

> i cleaned all electrical connectors with CRC cleaner and so far
> evrything seems fine but no sparks, no injectors pulses

You cleaned ALL connections?


> yeah haynes manual sucks.. i googled for information and narrowed the
> problems down to the coolant temp sensor, the camshaft sensor, the
> engine speed sensor and the ECU

The camsensor (AKA ign distributor) would/should not cause this problem and
the engine could run with the camsensor disconnected or bad.

> my car has a distributor so i guess the engine speed sensor is only
> for RPM and the ECU wouldn't cut off ignition when it's gone bad, a
> bad camshaft sensor maybe the cause, but then i thought the coolant
> sensor got the most damages during engine overheating and i cringed
> when i thought that maybe the ECU is dead too..

The crank sensor could cause a non-start problem!
I wonder if the needle of the tachometer would jump while cranking the
engine?

> my question is would a faulty coolant sensor cause the ECU to abandon
> ignition and injection? a safety measure perhaps?
> oh and i dont see the check engine light coming on when the ign key is
> ON and prior to cranking... and the OEM alarm wouldnt go off when i
> reconnect the ( - ) terminal... my ECU is dead?

Hmmm that check engine light NOT coming on is a clue!
Start looking at the fuses and relays. But like on a '96 I had, it may
just be a bulb! lol
I don't think a faulty coolant sensor would cause a no-spark problem.
I suppose you don't have a vag-com tool to plug into the ECM. 8^)
>


bi...@scn.org

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Jun 7, 2007, 9:13:17 PM6/7/07
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On Jun 6, 10:49 pm, "dave AKA vwdoc1" <vwd...@hotmail.com> wrote:
> REPLIES WITHIN
>
> <b...@scn.org> wrote in message

it's the ECU!!! i am sure

i dont have the vag-com.. :( it could have saved me a lot of time...
but yeah i did check the fuses and relays first thing.. i just can't
recall seeing the check engine light on recently, either when cranking
or running, but like you said i think it could be a bad bulb, mine had
been overworked. :)

i did clean all the connectors, spayed CRC cleaner on every each one
them... i only disconnected and clean the inside a few connectors that
i suspected getting showered by the coolant, and ones that go to
camshaft sensor, crankshaft sensor and coolant sensor

i found out that in case of a faulty coolant sensor, the ECU will use
the default 80 C or 176 F, so it's not the coolant sensor. also on
2.0L engine the camshaft sensor only works for advanced/retarded
timing and the engine can start with it disconnected, so neither the
camshaft sensor

i was able to download the bentley manual for BMW 3 series and check
the Jetta crankshaft sensor following the instructions, the resistance
across pin 1-2 is 570 ohms compared to 1280 ohms specs of that of the
BMW. checked with napaonline and they are different part numbers,
albeit looking exactly the same.. while i have no idea if 570 ohms is
still within specs, at least the sensor was not completely dead,
yes?

i reached under the rain gutter and tapped the ECU a few times with a
wooden stick, then cranked the engine and noticed a significantly
slower crank, some sort of resistance that caused by chamber
combustions, though weak and uneven.... also another good thing was
that the dash shift indicator worked correctly. tried cranking about
five times more but still no start.

so i pulled the ECU off the compartment, unpluged the harness and
examined the wires and prongs, made sure nothing was broken or loose,
put everything back, and the first thing i noticed was the dash shift
indicator turning wacko again.... i tapped the damn ECU again, and
this time it's like beating a dead horse..

i'd probably look for another ECU at a junk yard, dont know if i'll
have much luck finding used VW parts in houston TX... haha...

thanks again dave

dave AKA vwdoc1

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Jun 7, 2007, 11:40:45 PM6/7/07
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<bi...@scn.org> wrote in message
news:1181265197.2...@q66g2000hsg.googlegroups.com...

> it's the ECU!!! i am sure

WELL that is one possible cause, but I say check all of the wiring from the
ECM/ECU plug using the Bentley testing chart. If the ECM/ECU is not getting
power and ground then it will not work. ;-)
Bentley $44.07 http://tinyurl.com/22obwb or the long link
http://www.amazon.com/Volkswagen-Jetta-Golf-GTI-1993-1999/dp/0837603668/ref=sr_1_3/102-9487521-1645708?ie=UTF8&s=books&qid=1181272344&sr=8-3

The ECM should be the LAST thing to suspect and change!
Ign switch is one of the first I look at.


> i dont have the vag-com.. :( it could have saved me a lot of time...
> but yeah i did check the fuses and relays first thing.. i just can't
> recall seeing the check engine light on recently, either when cranking
> or running, but like you said i think it could be a bad bulb, mine had
> been overworked. :)

Some use the vag-com clones found on Ebay for around $20. I am not sure
that they work but for $20...........why not try one! ;-)

ebay has a '95 ECM going pretty cheap right now http://tinyurl.com/2g9rl7
http://cgi.ebay.com/ebaymotors/Electronic-control-module-ECM-95-Volkswagon-Jetta_W0QQcmdZViewItemQQcategoryZ33596QQihZ017QQitemZ270127194052QQrdZ1QQsspagenameZWDVW

You NEED to make sure all the ECM's numbers and letters are identical to
yours.


bi...@scn.org

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Jun 8, 2007, 1:29:27 AM6/8/07
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On Jun 7, 11:40 pm, "dave AKA vwdoc1" <vwd...@hotmail.com> wrote:
> <b...@scn.org> wrote in message

>
> news:1181265197.2...@q66g2000hsg.googlegroups.com...
>
> > it's the ECU!!! i am sure
>
> WELL that is one possible cause, but I say check all of the wiring from the
> ECM/ECU plug using the Bentley testing chart. If the ECM/ECU is not getting
> power and ground then it will not work. ;-)
> Bentley $44.07 http://tinyurl.com/22obwb or the long linkhttp://www.amazon.com/Volkswagen-Jetta-Golf-GTI-1993-1999/dp/08376036...
> ebay has a '95 ECM going pretty cheap right now http://tinyurl.com/2g9rl7http://cgi.ebay.com/ebaymotors/Electronic-control-module-ECM-95-Volks...

>
> You NEED to make sure all the ECM's numbers and letters are identical to
> yours.


hi dave

i'll look for it on eBay, thanks for pointing that out.. i've haven't
bought anything from eBay for like two years, but i'd been an eBay
junkie before...:)

long before it died my jetta would behave like a barometer, running
erratically on a humid day, misfires, hesistation.. etc. now it only
makes sense if a failing ECU is resposible for that.. why did VW
engineers decided to hide the engine computer under the rain gutter is
beyond me, did they set up their home computers in a barn too?
sheesh!!!

now what is responsible for a failing computer? beside short circuit,
i'd say water, heat, humidity, shock.. and so on.. and also some
pointers led me to the Split Fire spark plugs that i used in the last
tune up. when i pulled them out, 3 out of 4 look corroded and fouled.
some people believe that the unsual shape of the electrode creates too
much electro-magnetic noises (RF interferences) that eventually
damaged the engine computer chip. i am not so sure about that but i'll
stay with Bosch or NGK platinum from now on

til i find another brain for my jetta..

thanks

Tom's VR6

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Jun 8, 2007, 2:25:33 AM6/8/07
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In rec.autos.makers.vw.watercooled, bi...@scn.org wrote:

>
>
>long before it died my jetta would behave like a barometer, running
>erratically on a humid day, misfires, hesistation.. etc. now it only
>makes sense if a failing ECU is resposible for that..

That sounds like a coil pack.


> why did VW
>engineers decided to hide the engine computer under the rain gutter is
>beyond me, did they set up their home computers in a barn too?
>sheesh!!!

Putting the computer in the engine compartment reduces the number of
wires running thru the firewall.

Jim Behning

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Jun 8, 2007, 8:00:03 AM6/8/07
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That idea about excessive rf with Splitfire is about the stupidest
thing I have heard. But I am not an electrical/electronics engineer.
What kind of noise do you create with bad/leaking spark plug wires?
What kind of noise do you get when a trucker drives by with a cb
running at 50 watts? What do you get when you drive under power lines?
What kind of RF do you get when you are around a nuclear explosion?
Well I know the last situation makes for a bad day with many things
electronic. But if you don't have your iodine nearby it probably
doesn't matter if the heat did not get you.

The brains of most engine management computers have some basic RF
shielding built in. I believe my Toyota repair manual says do not
mount a CB radio next to the computer though. I am sure that also
means no shortwave radio nearby.

dave AKA vwdoc1

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Jun 8, 2007, 8:28:48 AM6/8/07
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Yeah Tom is probably right.
The ign coils (ignition transformer) are a very weak link in the 2.0s and I
ONLY buy new ones from the dealer. All of the aftermarket ign coils I have
seen and tested have failed!!! Sometimes after a week and sometimes after a
year but all have failed either providing a weak spark or no spark at all.
;-(

I have heard that using Splitfire plugs can be good if you use the proper
wires to go with it for the added benefit.
I WOULD NEVER USE SPLITFIRES IN MY VWS OR AUDIS. Maybe on my domestic Jeep.
NOT!
I prefer using the stock long life spark plugs!

--
later,
dave
(One out of many daves)


"Tom's VR6" <n...@mail.please> wrote in message
news:cbth63tt49sf1avnu...@4ax.com...

bi...@scn.org

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Jun 11, 2007, 12:58:55 PM6/11/07
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On Jun 8, 2:25 am, Tom's VR6 <n...@mail.please> wrote:


hi all,

i got into some serious seff-doubt after reading your replies, so i
tried one more time before heading to ebay... or a junk yard

i gave my cheap multimeter a fresh 9 v battery, carefully selected the
proper scale and again measured the crankshaft sensor resistance. it's
529 ohms and i was able to confirm the specs as 540 ohms +- 40 ohms

then i inspected the 3-pin connector that goes to the ignition module.
pin 3 is a steady 12V, pin 1 is a steady ground, pin 2 is controlled
by the ECU and provides disruptions to ground with an approximately 6
kilo ohms resistance when connected. i hooked up the circuit tester
between pin 3 and 2 then cranked the engine, guess what?? the light
bulb never flashed!!!

that's it, no spark because the primary coil's current never had the
disruptions that excite the secondary coil. i can have a super duper
coil and still no spark... and since the crankshaft sensor is good,
the ECU must be bad...

my 1994 jetta III has a distribution system, it's not using a coil
pack. by the way i think the coil pack is a very ill-concieved idea
unless each coil can be inspected and replaced individually... but why
coil pack??? sheesh!!! ignition by distribution has been around for as
long as automobiles are...

oh i can definitly see the point of mounting the ECU in the engine
compartment but i think i'd wrap my replacement ECU in saran... lol

and i started to wonder if there's a VW conspiracy... i did some
google and found out that some folks were flabbergasted when they took
their dead VWs to the dealers only to hear them talk in a different
language, the dealer would then refer to the crankshaft sensor as
impulse sender, and camshaft sensor as hall sender, and they never
suggested ECU problems as if those things would never fail... such
BS!!!

yeah the RF interferences theory concerning split fire plugs sounds
ridiculous, but the things certainly fail to provide fuel economy as
promised. i'll stay away from them.. bosch has a different approach to
a multiple-electrode spark plug, but i think it just a part of
automobile bull sh*t marketing...

anyway, a friend of mine told me about a yard in houston that hosts
many junked VWs, i'll come by and see this afternoon

just wanted to post a follow up...

Tom's VR6

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Jun 11, 2007, 2:15:39 PM6/11/07
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In rec.autos.makers.vw.watercooled, bi...@scn.org wrote:

>
>
>my 1994 jetta III has a distribution system, it's not using a coil
>pack. by the way i think the coil pack is a very ill-concieved idea
>unless each coil can be inspected and replaced individually... but why
>coil pack??? sheesh!!! ignition by distribution has been around for as
>long as automobiles are...

The coil pack has the *theoretical* advantage of no moving parts.
Also, one coil or drive transistor could fail and let a six cylinder
engine limp home. (not sure about a 4).

The coil packs have been notorious at flash over during humid
conditions, which then burned carbonized tracks into the insulator.
That same sort of thing could happen with a single coil, but with a
single coil there is probably more room to allow a bigger flash over
path. Your description of running badly with humidity made me think
of my experience with coil packs.


>
>oh i can definitly see the point of mounting the ECU in the engine
>compartment but i think i'd wrap my replacement ECU in saran... lol
>
>and i started to wonder if there's a VW conspiracy... i did some
>google and found out that some folks were flabbergasted when they took
>their dead VWs to the dealers only to hear them talk in a different
>language, the dealer would then refer to the crankshaft sensor as
>impulse sender, and camshaft sensor as hall sender, and they never
>suggested ECU problems as if those things would never fail... such
>BS!!!

Let's see if that new computer fixes your car. Good luck.

If you can start then, I would still look at the engine in the dark
to look for flash-overs on coil, distributor or wires. If the
weather is not foggy, make your own fog with a water mist.

bi...@scn.org

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Jun 13, 2007, 9:04:59 PM6/13/07
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On Jun 11, 2:15 pm, Tom's VR6 <n...@mail.please> wrote:

thanks tom

if automobiles makers realise that they can't get away with putting
lighter duty coils in a coil pack then i'd say coil pack design is
superior to distributor.. i'm sure they know well about statistics as
far as reliability is concerned but reducing bill of material still
their number 1 priority..

anyways, i believe my ECU was shot and a new ECU will fix my car..

i went to benltley publisher's site and found this thread.. the guy's
experiences with his 98 jetta is similar to mine,
and dave was right, OEM ign coil works when after market units don't..
it's all about the ign module working in conjunction, i guess.. but i
havent replaced mine yet..

http://tech.bentleypublishers.com/thread.jspa?threadID=11019&start=0&tstart=0

and then i found a used bosch ECU with matched part number on ebay for
$47 shipped.. bought it and now i'm wating for it to arrive

if it can run, i'd do a water mist just to see what's going on, but i
can never forget that the only times that my german lady quit on me
was when she's given a steam bath.. lol

will let you guys know how it'll go...

Hulk

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Feb 1, 2016, 6:18:01 PM2/1/16
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replying to bi241, Hulk wrote:
VW should be accountable for this failed electrical system

--
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Enrico stoffels

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May 25, 2017, 6:18:03 AM5/25/17
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replying to bi241, Enrico stoffels wrote:
Hi can u hlp me my jetta 3 crank but will not start

--
for full context, visit http://www.motorsforum.com/vw/1994-vw-jetta-iii-cranks-and-won-t-start-39162-.htm


photo...@gmail.com

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May 22, 2020, 1:18:47 AM5/22/20
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So What happened?
B/c I'm trying to fix my car too
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