boschboy951

I'm having an issue with my '88 951. When I start my car, it idles smoothly for about 30-45 seconds. Then the RPMs drop and it idles roughly. If I press the throttle, the engine dies immediatley. Also, the exhaust is white colored and smells like unburnt fuel.

My car has a 3" exhaust with test pipe, Autothority Mass Air Flow intake, and Autothority Stage 2 Performance Chips (DME+KLR).

What is wrong with my car?

Kool

White smoke=water

Blown HG is my guess.

Dr. Dynamics

Since I imagine its a cold start, the white might be condensation if in a humid area. Are your revs slightly higher than normal? You could be having a vacuum leak. When your rpms lower that means the ABV tends to close since car warmed up a bit, and fuel amount injected is lower. Verify also your map connector is tightly connected.

ilikemy944

Yeah my first guess includes a big vac leak - check the intercooler pipes/connectors.

Jeremy Himsel

Have you checked/replaced the 02 sensor lately? do the plugs look fouled? It's running fine on cold-start (off a predifined map that's' not reading from the 02 yet). Once the engine comes up to temp a bit it starts reading from the sensors and then you're seeing a change. When an o2 fails it tells the computer it is running lean, which causes it to dump more fuel (possibly what you're smelling). Unplug the 02 sensor and see if it gets any better or worse.

It would take a really bad vacuum leak to get it to die like that when you hit the throttle and you would be experiencing the problem at start-up as well (typically a low idle speed). I'm thinking it's a sensor issue. Also, check to make sure the MAF meter is still plugged in and the wires are not damaged.

hp18racer

If the O2 sensor isn't the problem, I'd look next at the TPS. www.clarks-garage.com describes a simple test for it.

You might also look at http://members.rennlist.com/951_racerx/ test fault codes link, describes how to make a blink code tester which will indicate a TPS failure.

I cut into my wire harness to put in a test point where I could get a multi-meter on the MAF signal. My autothority MAF produces about 0.8V at idle.