[Knownworldwide]

Ok so I was driving home yesterday nothing fast I just got gas and drove straight home at a lazy 50 mph. I went around a left hander at about 40 mph and went up to the light and all of a sudden the car stopped accelerating! Like i was out of gas but i just got gas. So right now i am thinking that the left hander might have sloshed some debris around that my fuel pump picked up and clogged my filter, fuel distributor, or fuel injector(s)?

I tested the idle and full throttle switches per the bently and they check out fine. I also tested the IAC and it checked out fine. I tested the CTS and it was fine. I even went as far as checking all these circiuts at the jetronic 25 pin connection for each input signal. I did notice that i did not get a correct reading for the knock sensor as per the test (maybe this is the problem?

Today I removed each injector and bled them to see if one was clogged. Number 1 was clogged so i cleaned it and they all sprayed fine so i reinstalled them. I tested the system for 76-81psi (CIS-E specs) and got 80psi so i am good for no fuel filter or pump clogs or return line clogs and fpr problems. So still i am thinking a fuel distributor problem (clogged or broken?)

Please chime in with some help. Sorry for thr novel!

 

[CafeRacer]

Your numbers are good but never assume the fuel filter is fine based on pressure. You could be getting low volume. Any throttle related issue with CIS I go to two places first.

With any CIS based system my favorite thing to do is pour in a concentrated mix of injector cleaner into a quarter tank drive it around to mix it up. Then let it sit over night. The injector cleaner does wonders on any varnish that's built up in the fuel distributor. For $5 its always a good thing to try first and far easier than rebuilding the dizzy to find out it worked fine.

When you tested the WOT switch did you raise the rpm up past 2500 and depress the switch? did the RPM drop or stay the same? CIS uses an electronic fuel enrichment. I would test both the switch so you know its sending signal that the throttle is WOT and that the Distributor is getting that same signal. Could be as simple as a busted wire. I've seen a single wire cause multiple and bizarre symptoms.

Its also a good time to lift the air cleaner top up and make sure the potenciometer is moving properly. That includes the pin that pushes in and out of the bottom of the distributer. TB or Carb cleaner works great for this. And on an older VW this should be part of your regular once a year tune up.

 

[Knownworldwide]

Your numbers are good but never assume the fuel filter is fine based on pressure. You could be getting low volume. Any throttle related issue with CIS I go to two places first.

With any CIS based system my favorite thing to do is pour in a concentrated mix of injector cleaner into a quarter tank drive it around to mix it up. Then let it sit over night. The injector cleaner does wonders on any varnish that's built up in the fuel distributor. For $5 its always a good thing to try first and far easier than rebuilding the dizzy to find out it worked fine.

When you tested the WOT switch did you raise the rpm up past 2500 and depress the switch? did the RPM drop or stay the same? CIS uses an electronic fuel enrichment. I would test both the switch so you know its sending signal that the throttle is WOT and that the Distributor is getting that same signal. Could be as simple as a busted wire. I've seen a single wire cause multiple and bizarre symptoms.

Its also a good time to lift the air cleaner top up and make sure the potenciometer is moving properly. That includes the pin that pushes in and out of the bottom of the distributer. TB or Carb cleaner works great for this. And on an older VW this should be part of your regular once a year tune up.

Ok so I pulled off my fuel distributor and swapped on a known working unit from my buddies gti. Made no difference at all. So i once again am led to believe there is an electronic issue or as you say maybe my fuel filter is clogged?? You really think so? Seems odd that my fuel system pressure test reads fine despite a possible clogged fuel filter. And the fuel delivery volume was up to spec as well.

You think my Jetronic ecu could be bad?
Ok

 

[CafeRacer]

A partially clogged filter will still let fuel flow and build pressure. It just can keep up with pressure. Think of it like blowing through a straw into a balloon. You will get the same presure in the balloon but it takes longer to do it since the flow is restricted.

Id try a filter.

considering the age of the car a faulty control unit could be a realistic problem too. See if you can borrow one to try. Its the only way to test it really.