rpmoore2

Hi all,

I have a 81 3.0L in a 77 911S.

Just recently I had a drivability problem where between start up to 2300 RPM under load the car would sound like it was running on half the cylinders, stumble, hesitate and hiccup. Oddly it would clear up on full throttle after around 2300. The car was fine up to the problem a week ago and oddly it started acting up right after putting gas in the car.

So I took it into the shop and the response was I need new Fuel Injectors. One was totally clogged and the others were border line. So we decided to replace all of them.

Anyway I picked up the car that night and well the same problem was still there. It turned out 2 of the new injectors were clogged again. This time they flushed the system. Untrelated they also adjusted the cold side of the WUR for me to help with the cold start.

So is it possible bad fuel could have caused this issue so suddenly. The shop believes 2 of the new injectors were simply bad. As a side the fuel filter was replaced around 600 miles ago. The motor was rebuilt at the same time. CIS FI was relatively left untouched on the rebuild.

rpmoore2

Well its back to it s old self. After driving it out to wash and wax I started it up and it started acting up again. This time the stumbling is not as bad as it was after the new injectors.

My 81 911SC 3.0L engine was rebuilt but before that it was added to my 77 911. I bet there isn't a o2 sensor.

I really need help what would control the car when there is load. I could use a technical explanation.

Car starts up cold or hot. Idle is a little low on cold; not terrible though. Shop indicated AAR is not working anymore.

Aside from that the car is better since the new injectors. It just stumbles on engine load.

I'm at a loss of what to do. It was really perfect for 1 day. One thing different is when I took the car from the shop the car was still warm. When the problem came back the car started cold. Could my injectors be clogged again. They did flush out the system, reinstall and set everything up.

dvkk

If you keep plugging injectors, I'd look into getting your fuel tank flushed out.

psychoideas

There are 6 tiny filters in the fuel distributing head. One under each of the injector lines. There is also a micro screen into the input of the WUR.
The tank might have crap in it but it should not pass the filter. That's what a filter is for.