# 1990 1.8 Jetta hard start and shutting off and reving???



## dhenry1223 (Feb 8, 2011)

I have a 1990 1.8 jetta. Sometimes it will start for a second or two and just shut off.  After 10 tries or so it will stay running. sometimes it will cut in and out while driving and also just shut off while driving. Today it started to rev high and then it will rev low like it is almost going to shut off and then it will rev high again. It will do this repeatedly at a stop or with the clutch in. :banghead: i WOULD APPRECIATE ANY HELP YOU CAN GIVE ME... THANKS GUYS!!!


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## Seax_Smith (Jun 1, 2007)

Start with an "ether test" for vacuum leaks and actually check and confirm your grounds in the bay.

Replace the BLUE CTS.

Try jumpimg the fuel pump relay and see what happens. 

Symptom is to random to be more specific, so that's all I've got.


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## thesumof41is5 (Aug 6, 2009)

check out the isv, i made the diy for deleting it simply to figure out if that was your problem


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## JHughes89 (Sep 8, 2009)

I know whats going on with his engine and can be more specific. I do not know the problem, but I am getting close.

Problem:
At idle, it runs a very poor idle, sounding like major caming going on, but you can feel the engine hit something, like a head is making contact where it shouldn't, but dont be afraid, that is not your problem either. At times your engine revs to about 3k RPM, hold, and drop back to the poor idle. At times the engine hits hard enough and it dies with a slight squealing of the belts. Trying to restart, takes about 10 seconds of HOLDING your ignition on for the starter.

Solution:

This is maybe a sensor problem. I believe, looking at mine, that the MAF sensor is probably dirty, or is bad. This could ALSO be caused by your O2 sensor, especially if you are like me, with an exhaust leak right underneath your drivers seat and can smell a lot of gas, which leads me to the solutions. This could also be in your Throttle Body, try cleaning that off, it may help.

I have not had a chance to fix the issues in the Solution part, so do not hold me to it. I am working on it slowly, but due to my job, I have a lack of good time to work on my car, so I also ask, if you come across a solution, let me know, as mine is having the EXACT same problem.

I have reason to believe this may also be electrical to the sensors listed above, because for 2 days, mine ran WITHOUT the issues, but due to my starter not wanting to work, I disconnected the battery and when I fixed the wiring issues on my starter and reconnected the battery, the problems came back.

Again, if you can find out the solution, let me know, as time is very limited for me due to work. I will work on my end with what time I have to find out what I can, and will continue to throw up ideas to bounce between everyone here.


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## Tougemachine (Jun 28, 2010)

my 91 digifant started doing this last week..except it was real bad. one thing is ive always power washed my engine once or twice a week. (im not sure why. i just do).

my battery died on me about a month ago so ive been driving my caddy. id go every few days and jump it, idle it and drive it around the block. 

so last weekend i replaced the battery and started her up. purred like a kitten with an autotech 270 cam in it. then went to the carwash and pressure washed the engine like always. after i was done the car wold not start :banghead:

every once in a while id hear a big BANG from the exhaust. but just woldnt start. about two hours of tinkering and trying to start the motor it finally fired up. idle was fine..as soon as i went to leave i hit the throttle about 50% and it shut off..

it took another 45 min to get started again. it started, i limped it around. it ran ok.. 
anything over 4000 rpm it was like a rocket ship..i drove it about 120 miles that day and like i said, it ran ok. liked high rpm and WOT. replaced the blue temp sensor today and it ran waay smoother, no lag. awsome.....NOT!! it ran great till i got down the street. as soon as i hit WOT the engine shut down. took about five min of trying to re start and it ran crappy. repeated this over and over till i got it home. it shuts off if i go over 3500 rpm also

sory for the long winded explanation but i cant figure out how else to explain it.eace:


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## Seax_Smith (Jun 1, 2007)

Check the hall sender plug on the side of the distrib. you probably have al least some moisture in there, and probable have moisure in other electrical conections.

Power washing your engine is fine if you prep for it. Get a tooth paste tube sized tube of dielectric grease and coat every single electrical contact, including the ground. clean everything before you grease and reinstall/ reattach. Dont forget the plug boots, the distrib boots either, and seal the d-cap on with dielecrtic grease as well. (your digi ECU will like you if you clean alll the contacts before greasing).

Get all the elec stuff moisture proof, and power was away. avoid direct shots at teh distrib, AFM and coil and try not to directly hit the plug/socket conections. Also leave the car idling as you power wash. that way you will hear teh stumble if you start getting water somewhere the car doesn't like.


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## dhenry1223 (Feb 8, 2011)

*Fixed*

I did a bunch of numerous things including cleaning the MAF. Nothing worked. I went to the parts store and bought a cap and rotor, put it on, and now it runs like new!!! put 250 miles on it since and no problems what so ever...


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## dhenry1223 (Feb 8, 2011)

*Fixed...*

I did a bunch of numerous things including cleaning the MAF. Nothing worked. I went to the parts store and bought a cap and rotor, put it on, and now it runs like new!!! put 250 miles on it since and no problems what so ever...


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## JHughes89 (Sep 8, 2009)

Bad news: Check your Coil Pack(Up against the firewall just above the heater core hoses)

Mine is taking a nose dive, and I have to replace it. My cap and rotor are >3k miles on them. Did a check on several electronics this morning, and the coil pack is dying out quickly, unless I have it wrong, which may happen. ISV is also taking a nose dive, gonna try the delete that was posted up above.

If ANYONE can help me out with this, I will try to get a YouTube vid up soon to hopefully help explain. I need help, this is also my daily driver, and I gotta keep her running.


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## Seax_Smith (Jun 1, 2007)

The coil stuff is all covered in the Bentley, and there isn't much to it. Check the current flows to be sure you are hooked up to it correctly, and after that the coil will meet spec or it wont. If it is right on the edge assume it didn't meet spec.

THe ISV delete is a cover up / ghetto riging to bypass a known issue.

THe ISV is showing the symptom, therefore if I remove the ISV I remove the smptom and therefore the issue is gone since there are no more symptoms! GREAT LOGIC!


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## 89CARAT8V (Oct 22, 2010)

This is probably the most common problem with the digi cars. Like everyone else, I also had this happen. Ive been diagnosing it for quite a few months, and have improved it but havent gotten rid of it yet. OP heres some things youll wanna check (most have already been said.)

Vacumm lines-Make sure they are all good and not ripped or deteriorated.
MAF sensor-Check it out and make sure its not clogged or working improperly.
Grounds-One of the best places to start, make sure every ground and wire connection is in good shape and secured properly.
CTS-Buy a new coolant temp sensor and replace it. Theyre too cheap not to.
Throttle Body-Pull it off and clean out all the gunk and make sure the doors are working properly.
Idle Screw-Pull the idle screw out of the throttle body and make sure the o-ring on it is still good. If its cracked or torn, replace it. (This was part of the problem on my car.)
ISV-Just delete that son of a *****. I pulled mine off and blocked off the hose holes, and it runs so much better. 

Thats all I can think of at the moment. Mine idles real low when I start it now, but if I let it warm up for about 10 minutes, it drives like a dream with no problems. Just the initial start up is funky. Im waiting for my brand new vacumm lines, dist. cap/rotor, and a few other things to show up in the mail then Ill see how it does.


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