# Engine stalls on idle after 10 to 20 seconds



## ar1g3 (Nov 30, 2015)

I just replaced all the o-rings around the injectors and injector inserts. But now my engine won't idle. It'll start, but after 10 to 20 seconds it'll die unless I apply a bit of throttle. It didn't do this before. I did find the injectors very hard to push in with those new O-rings, but it looks as they're in now. 

Anyone here has any idea what might cause this? Again, before pulling the injectors and changing the O-rings the car run fine, it only stuttered on acceleration which lead me to searching for air leaks which made me discover the worn O-rings.

Thanks in advance!


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## ar1g3 (Nov 30, 2015)

Could this be the source of my stalling problem? One of the new inserts was cracked, I probably messed up when installing them. Feel like an idiot right now.


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## ar1g3 (Nov 30, 2015)

UPDATE: the cracked insert was not the cause of the stalling problem. It has been replaced and the engine still stalls on idle. As soon as I apply even the slightest bit of throttle the engine keeps running, and it runs perfectly smooth. 

And like I said, before I replaced the inserts and O rings around the injectors there was no problem. To me, this makes me think there is something wrong around the injectors, but everything is new and installed according to VW's specifications, and there is no visual damage or malfunction. The injectors should all work aswell, since when you apply even a little bit of throttle the engine runs smoothly.

I also tested the idle stabilizer valve on continuity, voltage and if it works like it should. All tests were positive, so I don't think the valve is at fault.


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## ps2375 (Aug 13, 2003)

ar1g3 said:


> I also tested the idle stabilizer valve on continuity, voltage and if it works like it should. All tests were positive, so I don't think the valve is at fault.


Is it being controlled correctly or even at all?


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## ar1g3 (Nov 30, 2015)

ps2375 said:


> Is it being controlled correctly or even at all?


Yes, there's 12V between the center terminals and +/- 10V between each of the outer terminals and the center terminal. When the iginition is on the valve hums, and when you remove the air hose that comes from the intake boot and you look inside the valve you can see it working. I don't know if it's duty cycle is correct, but since it was working before I changed the injector O rings I suppose it is correct.

Could it be that I need to adjust the idle scew on the throttle body? Maybe in the past someone lowered the idle rpm setting to account for the vacuum leaks around the injectors, and now when the whole system is air tight there isn't enough air entering the engine so it stalls?


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## ps2375 (Aug 13, 2003)

I would adjust the idle screw. That is what it is for,the ISV is just there to "assist" when you have additional load added like the AC or lights and blower motor.


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## ar1g3 (Nov 30, 2015)

Id screwed it out a few turns and now it keeps running, but I think it idles a bit high, my guess is it's around 1100RPM now. The problem is I'm not able to see the RPM. The instrument cluster doesn't recieve RPM signal. Is it true it takes the RPM signal from the alternator?


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## ps2375 (Aug 13, 2003)

ar1g3 said:


> Is it true it takes the RPM signal from the alternator?


No. Not having a manual for a CIS-e car, but I'd have to say that tach gets it's signal from the coil.


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## ar1g3 (Nov 30, 2015)

ps2375 said:


> No. Not having a manual for a CIS-e car, but I'd have to say that tach gets it's signal from the coil.


I have a Bentley manual, but I can't find the tacho in the current flow diagrams. For my 1988 German production mk2 Golf 16v I can't find it in the main electrical system diagrams, and there don't seem to be close up current flow diagrams for the tacho like you have for the airconditioning.


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## ps2375 (Aug 13, 2003)

Then you aren't reading it correctly, cause it'll be in there. Look at the instruments section of the diagram.


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## ar1g3 (Nov 30, 2015)

ps2375 said:


> Then you aren't reading it correctly, cause it'll be in there. Look at the instruments section of the diagram.


You are right, the tacho was in the engine electronics section, not in the main electrical system section. It's a black/red cable. It's connected to the coil, which means it's not a loose connection that causes my tacho to not be working. I think I'm going to use an osciloscope to determine the RPM of the engine during tuning. I don't have time to fix it first, I want to do the tuning at college where we have better work conditions than I have at home.


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