1986 audi 5000 turbo cs starting problem

[thefox]

The car has good compression on all the cylinders and appears to have spark going to all cylinders, I just put in new spark plugs, spark plug wires, rotor and cap. The car almost starts from what seems like residual fuel when it is cold and has been run previously, it will fire and almost start, then die, and then it won't fire at all and you can turn it over and turn it over with no hint of starting, then all of a sudden it will fire and start after turning it over way to many times. After it starts though and has been warmed up, it seems to start pretty decent. I am new to Audi's and don't know what the problem could be. Please help.

[TommyL]

Had the same problem with my 5000, could be a few things.

#1: Check for any vacumum leaks, InExile mentioned a good way of using a can of brake cleaner to find a leak.

#2: Clean up any sensor connections, and especially cleaning things like your idle air control, intake boots, clean whatever anything could have built up.

#3: It might sound like your running on your cold start injector, check to see if you rfuel pump is working, and if it is actually on at ignition, test lightat fuse box.

#4: When you crank your motor, is there a large puddle of fuel on your piston. These mechanical fuel injectors like to stick open and have a gunk buildup if they sit for a bit.

Was it sitting for awhile?

[TommyL]

Whoa sry, didnt read the part where it starts fine after warm up.....

[thefox]

The car had been sitting awhile, but started fine after it had been sitting. It ran fine for a couple of days, then developed the starting problem. When you take the spark plugs out after cranking it over they appear dry.

[TommyL]

Just a suggestion, it could be a bad temp sensor,

[InExile]

still could be a vacum leak ... when motor is warm it is easier to start with a vacum leak, cold motor does not like vacum leaks at all ... check all air hoses the inside of them too (they do brake down from the inside) ... crank cace ventilation hose ... see if the CIS plate is moving freely

[thefox]

Where was it that InExile mentioned how to check for vacuum leaks with a can of brake cleaner? That seems likely.
Whoa! Nevermind, I found it. It seems like it could be the cold start injectors too based off of other peoples posts. I am getting a manual for the car and gonna do some checking.

[InExile]

cold start injector is the last thing on the list to check ... yes def get a manual preferably a bently one .... vacum leaks -> temp. sensors -> leaky injectors (look inside the cylinders) -> restrictions in the fuel delivery (a new fuel filter is not going to hurt) -> plugs and wires, distr. cap, rotor .... the idea is to make sure that all the simple and cheap stuff is in good working order before you start dropping chash like a mad man replacing expensive parts that are not broken

[questur83]

my guess is the fuel pump/ground problem. Do you hear the pump running??? If not, nice easy fix...

[thefox]

I think it is running, I am not sure, if the fuel pump wasn't running why would it eventually run just fine?