1988 325is - first start of day is easy, but subsequent starts are hard

[Steve2002]

1988 325is AT with 140k. In Massachusetts but not driven in winter.

My first start of the day is easy. I crack the key, and the car starts immediately.

The second start of the day is a hard start. The car cranks fine, but you have the feeling it might not start. It always does start, but it might stall if you do not depress the accelerator. I smell fuel, and the gas filter has a fuel stain line that runs across the narrow part of the filter from the AFM butterfly. The second start is hard even after 2 hours of the car being turned off.

This has been an ongoing problem for a couple of years.

I have replaced the air filter, gas filter, throttle position switch, fuel pump relay, crankshaft position sensor, and changed the oil. The car had all new ignition components within 20k miles.

Also, I have a 1988 325i that always starts easily and runs great, and I traded the AFM and the ICV with no change to the starting issue.

I know the TPS I replaced was bad. It tested bad. When I replaced the TPS, it fixed a run-away acceleration problem when the A/C was on and the car was shifted to park. I am pretty sure I have the TPS adjusted correctly. I tested it at the 3 pin connector when installed with accelerator off and depressed.

At one point the car was never starting, and replacing the CPS fixed that.

[TobyB]

Put a fuel pressure gauge on it, and see if it loses pressure when you switch it off.

Likewise, when it's starting hard, floor it and crank it until it catches.

What we're looking for are leaking injectors that are flooding multiple cylinders
when it sits. This generation of injector clogged eventually, and one
of the modes was that it dribbled a little after shutdown. That floods the car,
and makes for hard hot starts. It goes along with your fuel smell, and the
oil level that might go UP instead of down over time.

worth ruling out,
t

[digger]

I'd pull injectors and get them tested and go from there

[82eye]

both of the above. i'd go one step further and replace them all with a newer style open 4-pintle. it helps smooth idle, increases efficiency, and gives a little better throttle response. it won't knock your socks off, but the whole engine will be a bit happier.