Idle/Timing is evading me

[wnmimms]

1979 Euro 930

I thought I'd start a new thread, one focused on the immediate issues I'm having vs. the somewhat broader one on my car dieseling.

In short. I have replaced the following:
CDI with one from PartsKlassic
Transformer from PartsKlassic
Beru wire set

I have checked the following components for proper function as well as checked for vacuum leaks with a smoke generator
Warm up Regulator
Throttle Bypass Valve
Vacuum Controller
Fuel Distributor Control Pressure and System Pressure
Verified all injectors are generating a fine mist equally between all the cylinders
I set the AFR mixture screw so that I was just starting to see a fine spray coming from each injector.


After doing the above I am able to achieve a steady idle but with the vacuum line to the distributor disconnected (this is counter to what is in the manual for a Euro car) and rotated to achieve Z1. However, when I connect the vacuum line back to the distributor the RPMS slow from near 950RPM and steady to 650 and sounding terrible.

Unfortunately, as I bring the RPM's up I get a lot of backfires from the exhaust and can't get past about 2k on the tach.

Sound clip of it running:
https://youtube.com/shorts/Z5dLfo0jJ6w?feature=share


I have a Wideband but hadn't installed yet.

Any suggestions on what I might be missing?

Vacuum leak?
The idle control screw is nearly completely closed. Indicative of a vacuum leak somewhere ie. too much air is making its way in downstream of the Air Mixture Control unit?

I have searched and searched for a vacuum leak procedure specific to the turbo. When I did it I can't be completely certain that I was able to test the complete system as I wasn't sure where to plug in the smoke generator so I just moved it around to different areas of the system. Any help on this would be appreciated too.


Thanks,

Bill

[mark houghton]

I just read all of the comments in your dieseling thread. I would be beyond frustrated at this point. Appears you've addressed everything with excellent input from the masters. I'm not clear if you ever got the 'no spark to #4' resolved or I just missed it. Not sure if I can be of any more help but will follow until something clicks in my brain.
One comment: you mentioned the idle adjustment screw as being almost all the way screwed in. Even in a properly running car that would cause a very low idle in and of itself. Open that dude up and see if you can't maintain proper idle with the dizzy vacuum line attached.
Do the '79 models have an AAR for setting high idle when cold? Have you checked it?

[mark houghton]

Originally Posted by wnmimms

1979 Euro 930

I thought I'd start a new thread, one focused on the immediate issues I'm having vs. the somewhat broader one on my car dieseling.

In short. I have replaced the following:
CDI with one from PartsKlassic
Transformer from PartsKlassic
Beru wire set

I have checked the following components for proper function as well as checked for vacuum leaks with a smoke generator
Warm up Regulator
Throttle Bypass Valve
Vacuum Controller
Fuel Distributor Control Pressure and System Pressure
Verified all injectors are generating a fine mist equally between all the cylinders
I set the AFR mixture screw so that I was just starting to see a fine spray coming from each injector.


After doing the above I am able to achieve a steady idle but with the vacuum line to the distributor disconnected (this is counter to what is in the manual for a Euro car) and rotated to achieve Z1. However, when I connect the vacuum line back to the distributor the RPMS slow from near 950RPM and steady to 650 and sounding terrible.

Unfortunately, as I bring the RPM's up I get a lot of backfires from the exhaust and can't get past about 2k on the tach.

Sound clip of it running:
https://youtube.com/shorts/Z5dLfo0jJ6w?feature=share


I have a Wideband but hadn't installed yet.

Any suggestions on what I might be missing?

Vacuum leak?
The idle control screw is nearly completely closed. Indicative of a vacuum leak somewhere ie. too much air is making its way in downstream of the Air Mixture Control unit?

I have searched and searched for a vacuum leak procedure specific to the turbo. When I did it I can't be completely certain that I was able to test the complete system as I wasn't sure where to plug in the smoke generator so I just moved it around to different areas of the system. Any help on this would be appreciated too.


Thanks,

Bill

See the comment I left on your dieseling thread re: smoke test, and/or my own thread for smoke testing. I used the method Alan suggested.

[macronbill]

The comments are not helping