Cold start and rough running issues
I looked in the FAQ's and DIY section for information and while I found some, the links for the WUR are no longer working. I have a CIS book that details how the components work, but nothing about settings and such as it's a general overview of the CIS system, regardless of vehicle.
Here is what's going on:
- On cold start, the car will start, run for a few seconds, then die. I figure the cold start injector is working and it's starting from that. Haven't pulled to verify, though.
- If I can keep it running, I have to lay into the throttle to keep it running, at generally that's above 1,500 RPM's.
- Once it's warm, it will stay, running, however the idle must be above 1,500 RPM's or it will die. I have actually had to adjust the throttle cable to keep it running as there isn't enough adjustment in the idle screw to maintain idle.
- I checked for vacuum leaks and found a few: throttle plate linkage, charcoal canister, and one other, but they are all VERY minor.
- I checked fuel pressure and it is a steady 70 psi at the fuel distributor.
- Once the engine has warmed up, it runs better, but only above 1,500 RPM's, and even there it's not steady.
- I did time the engine once it was warmed up to make sure that wasn't a factor and timing was off, but still having the same problems.
- I have not tested the pressure accumulator, but starting when warm is much better.
- I don't have a repair manual, so I don't know what the setting for the air plate on the distributor is supposed to be when the engine is off.
- I have messed with the mixture screw in the top of the distributor, but did a rough adjustment: Pulled an injector, turned the screw until fuel just stopped coming out of the injector, then turned it another 1/8 of a turn.
- I disconnected the O2 sensor in case that was an issue, but no difference in performance.
- Both the WUR and the air bypass valve are rebuilt units from Fuel Injection Corporation.
I pulled the intake boot between the distributor and the intake manifold: the plate moves freely, but there is a film of oil/dirt on top of the plate. If I lift the plate while activating the fuel pump, I can hear fuel moving through the injectors.
I am re-learning the CIS system, and this is the first time I've had to figure it out on an e21.
Thanks for any help!
Any ideas/suggestions at this point?
Last edited by zaffer; 03-15-2023 at 02:35 PM.
Current vehicles:
2011 Toyota Tundra SR5
2002 BMW 330iT manual (Daily)
2006 MB E350 Touring 4Matic (Wife's daily)
1997 Mazda Miata M-Edition
1987 BMW 325e manual (Wife's)
1982 Fiat 2000 Spyder
1984 VW Rabbit GTi
1975 Porsche 914 2.0L
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