Car stalls when hot...

[Optigman]

OK, to make a long story longer (burn_your_money) has already heard this...

I just did a complete rebuild of my 1.8 Jetta GLI. This morning I got everything back in the car and it started right up.

My problem is this, once the car warms up, it is really difficult to restart the car. I drove it around the block and it stalled when either letting out the clutch or coming to a complete stop. I've checked and reset the timing and checked the distibutor to make sure it's firing on time and everything checked out. My mind is just a little tired at this point and I'm hoping that someone can point out the obvious.

Thanx

[burn_your_money]

A shot in the dark but maybe your fuel pressure accumulator is not working. This might explain the inability to restart.

The more I think about this, the more it makes sence. Of course my knowledge of engine components is still limited....

[jettadude]

ok im quite good at this problem, i need to know the year of your car and your fuel system. and i should be able to tell ya what is causeing it.

[Optigman]

ok im quite good at this problem, i need to know the year of your car and your fuel system. and i should be able to tell ya what is causeing it.

It's an '86 Jetta GLI 1.8L with a complete rebuild. The fuel delivery is CIS-E.

[Mr_Diesel]

If not digifant, my first suggestion would be timing, so mabey have a shop test your timing.

#2 If you just did a rebuild the headgasket might have failed... Check your compression... Ensure that each cylinder is abovve 90-95psi for optimal performance.

[Optigman]

If not digifant, my first suggestion would be timing, so mabey have a shop test your timing.

#2 If you just did a rebuild the headgasket might have failed... Check your compression... Ensure that each cylinder is abovve 90-95psi for optimal performance.

Checked timing 3 times, along with timing gun onto flywheel, all ok.

compression is great on all 4, idle is smooth, acceleration is great.

I'm convinced that it's fuel mixture. When I rebuilt the cylinder head the valves were cooked, it's a wonder they closed completely with all the carbon buildup. I'm going to try playing around with the mixture either tomorrow or Friday.

Any helpful hints for adjusting fuel mixture Mr_Diesel, your help is greatly appreciated. Thanks again.

[GoodDayForADrive]

If not digifant, my first suggestion would be timing, so mabey have a shop test your timing.

#2 If you just did a rebuild the headgasket might have failed... Check your compression... Ensure that each cylinder is abovve 90-95psi for optimal performance.

How do you check compression?

[jettadude]

ok well here is what might be causeing the prob.

all VW's from 77-88 have CIS fuel injection, once of there classic probhlem is hot starting, after you turn off the car the heat from the engine and ehuast pipe soadk into the injectors and the injection likes and boils the gas into a vapor. then you have vapor lock. its kind of backwards vapor lock because vapor lock is usually an air space in the line between the fuel tank and the pump. bosh installed a number of solution to this problem, one of which was the fuel pressure accumulator.
accumulator fail externally and internally, in all VW's they sit under the rear passengerside seat and it exposed to salt and external corrosion. defect number 2 is internal. the internal diphragm spings a leak and the accumulator gets water logged with gas on both sides of the diaphragm and is less effective. this is more common. when the accumulator is not working it contributes to the hot start problem.

you should replace the "O" rings on the injectors, this causes vaccum losss so the throttle plate doesn't lift, so no start.

your O2 sensor could be bad as well. i kno in DIGI the coolant temp sensor plays with things. but i don't think it would matter with this. but check your O2 sensor and all of the above.
hope this helps

[Optigman]

Not as difficult as it sounds, you warm the car up to normal operating temperature. Remove each spark plug, attach a compression tool, turn the engine over a couple times and the pressure in psi is recorde on the dial. You must repeat the step for each cylinder.

[Optigman]

jettadude -

Thanx, that is not what I would have though. When I did the overhaul, I didn't replace the injector O rings, I thought the others were fine, however I have them still and will have to replace them. What's the easiest way to remove the injectors while in the car and reinstall them. I'm used to pulling them out whith the head out of the car.

As far as the regulators, I'll have to wait until it stops raining probably tomorrow night or saturday.

I'll keep you posted.

[jettadude]

you need a CIS injector puller tool. here go to this site and order a catalog, that is where i got the hot start problem from. there tech tip section. www.partsplaceinc.com they have the best parts catalog for VW's.

[burn_your_money]

Not as difficult as it sounds, you warm the car up to normal operating temperature. Remove each spark plug, attach a compression tool, turn the engine over a couple times and the pressure in psi is recorde on the dial. You must repeat the step for each cylinder.

Don't you have to disconnect your fuel pump or something?

[Mr_Diesel]

If not digifant, my first suggestion would be timing, so mabey have a shop test your timing.

#2 If you just did a rebuild the headgasket might have failed... Check your compression... Ensure that each cylinder is abovve 90-95psi for optimal performance.

How do you check compression?

With a PSI compression tester... Take out 1 spark plug and start the engine for a brief second.

[Optigman]

you need a CIS injector puller tool. here go to this site and order a catalog, that is where i got the hot start problem from. there tech tip section. www.partsplaceinc.com they have the best parts catalog for VW's.

You don't know how long I've been looking for that site! I used to get there catalogues along time ago, but I thought they were no longer. That's awsome. Thanks alot!

[jettadude]

np man. hope it helps yea in your quest of finding the holy hot start problem. lol :lol:

[Optigman]

Update -

Installed new O rings on the fuel injectors this afternoon. This is a step I forgot to do during the rebuild. The car idles better, and corrected the warm start issue. I just need to tweak the rest of the settings, advance timing about 6 degrees and I'll be set.

Thanks to all who offered help!

[Jettaman]

If i were you i would check your O2 sensor, my 88 Jetta GLI had somewhat of the same problem, when the car got warm it would start running like crap and then end up not wanting to run at all. I unhooked my O2 sensor and the car ran great, didn't have as good of gas mileage but ended up getting a new one put on there. VW had a lot of problems with O2 sensors on a certain VW. One of my contacts that works for Jordan Motors out of Des Moines got me one of those and my dad and i hooked it up and my car runs good as new, well except for the damn oil it burns. If ya got any suggests, look at the A2 engines.

[burn_your_money]

How is your doing man? Did you get it all tweaked out?

[Optigman]

How is your doing man? Did you get it all tweaked out?

Hey Ty, sorry it's been awhile since my last update! The 86 GLI is on the road and screamin! Went for the emissions and safety inspection on Monday and passed with flying colors. Had new 195/50/15 rubber mounted on my BBS basket weave rims and with the Neuspeed lowering, there is virtually no wheel gap. Installed the Techtonics exhaust, 270 cam, adjustable cam gear and assorted goodies about two weeks ago. Was having some trouble with stalling, I feel it was just working out old bad gas from the system along with a bad relay for the Idle Stablizer Valve. (don't ever let anyone tell you it doesn't require a relay, because it does!) I'm actually letting my 2001 VW sit, and driving the 86 as much as possible, it is SOOOOO much fun! I'll have more pics to post soon.

[Mr_Diesel]

Man that's awesome... Usually when the 1.8L 8V dies it crashes and burns like hell... If you sucessfully revived a 1.8L and worked out all the bugs, that is a surprising accomplishment. Great work.

[burn_your_money]

Man, that sounds like one killer car. It almost makes me want to drop a VR6 in one of my rabbits or turbo my CIS.

I can't wait for those pictures :D

[Optigman]

Man that's awesome... Usually when the 1.8L 8V dies it crashes and burns like hell... If you sucessfully revived a 1.8L and worked out all the bugs, that is a surprising accomplishment. Great work.

Been searching for a name for the car Diesel, I think you've solved my query. I might name the GLI Pheonix, it has risen from the ashes....

[jettadude]

nice, very nice.