Joined: 06 Sep 2019
Location: Richboro, PA
|Posted: Sat Oct 05, 2019 11:27 am Post subject: Odd CIS Problem WARM Control Pressure Too Low
|I have logged a couple hundred miles on my new to me 1980 924 M471 NA. Car runs very well with a couple small exceptions.
Cold start: Always starts first crank and dies, start a second time and stumbles to life
Warm Start: Very difficult, flooring the pedal seems to help.
Runs strong when cold, seems to stumble off the line when warm.
Replaced accumulator and fuel filter. Did pressure tests today. Cold pressure is 29, warm pressure is 39. System pressure is 68. Residual pressure holds high (around 30) for well over 45 minutes.
At one point, the warm pressure did rise to 47 and the car was very responsive but mysteriously dropped again.
Have some experience with CIS from my 928. Unfortunately, this problem is a little unique. I am assuming a WUR disassembly may be in order? Trying to figure out the common denominator between all these issues. Thoughts?