Eirrol

So I took my '86 944 to do state inspection and the guy said it can't pass because it needs spark plugs, plug wires, and air flow meter/sensor replaced. I highly doubt I need all of these.

However what happened was when I started the car yesterday morning, the engine started acting weird. It idles fine but it drops down to 1000 rpm if I try to rev it to 2000. It just comes back down at 2000. Then after sitting there for 10 minutes, everything is fine again.

That night when I was coming back from school, the car stalled on the way home and refuses to idle. At first I can still start the car but as soon as it stars it stalls, so I can keep my foot on the gas to rev it to prevent it from stalling. Then after a few tries it just won't start at all. Letting it sit for another 10 minutes or so, it starts fine and drives fine again.

Then I tightened the screws holding the pipes together and tried again today and everything is fine. But I really don't want to risk that it stalls on the expressway again.

Should I really replace the air flow meter, or is it something else?

Tiger03447

What state are you getting the car inspected in? CA? sounds pretty extensive for a guy who runs an inspection station to make these comments...I think you need further checkout. You said you tightened the pipes...what did you mean by that, pls explain further..were any wires involved? Are you getting any fuel pump sounds when you turn the key? do you get tach bounce when you crank it? Need more info..thanks, Tiger 03447

Eirrol

Thank you for your quick reply. I am inspecting in PA, they guy said it didn't pass so I asked him why, and paid for diagnostic service, then he made those comments on the report. I just tightened the screws holding the pipes, there are 3 of them near the air flow sensor. Like this



What does the fuel pump sounds like when I turn the key? I have no idea.
The tachometer does bounce very slightly when I crank.

V2Rocket

jiggle the air flow meter wiring, the afm as a unit seldom actually fails but they can get out of spec.

check your throttle position sensor, it might have a bad idle switch.

Eirrol

The wiring is fine. Where is the idle switch?

divil

The fuel pump will only run when cranking/running so you more than likely won't be able to hear it.

There are test procedures on Clark's Garage for both the air flow meter and throttle position switch (which includes the idle switch).

V2Rocket

Do you know for sure if the fuel pump runs while cranking?
This weekend I changed my fuel filter and lost all the fuel between filter/lines and wouldn't start - I jumpered the relay socket to run the pump and it started right up, shut it off, replaced relay, and all is well. Maybe it just needed a prime.

divil

I think the pump must be running since he can start the engine and get it to keep running with some throttle. But then it won't run any more until it's let sit for a while...flooded with fuel from running very rich maybe? OP next time you get it to where it won't start, pull the plugs and see if you can spot any signs of that.

konakat

Just unplug the TPS and see if all your issues go away. The connector is on the bottom side of the throttle body. Chances are the switch is stuck and is telling the DME that you are always at idle.

Eirrol

Thanks. I will try these methods when it happens again. I drove it to school and back today with no issues at all.