Mike951

My '86 951 has been stumbling, cuttign out at idle, and running rough. I am changing the fuel filter becasue maybe it is not getting fuel, but then I read some stuff about the Temp Control Sender for the DME, and now I'm thinking maybe that is my problem. I read that if it is messed up, your car runs to rich or too lean. When I dscovered this problem I was driving the car and I smelt a burning firecracker smell, kinda like sulfur. Does this smell have anything to do with too rich or too lean?
Thanks
Mike

Kevin Baker

YES, thats it! The catalyst is overheating due to a lean condition, change the DME temp sender before you melt the cat.

Mike951

If the temp sender is not the problem, it should be a problem with the fuel delivery, so I should check fuel pump, filter9I'm actually changing that out tonite), and fuel pressure? Hopefully the temp sender does it.

Thanks

Mike951

If my temp guage bounces, stabalizes, and then bounces, is this probably becasue of the temp sensor?

944Play

There are two temp sensors -- one for the gauge, with two spade terminals, and the "NTC II" sensor for the DME, which has an injector-style connector.

Mike951

Ok, so what would cause my guage to bounce, bad grounds or corroded connections? Where would be the best place to check for these things?

Thanks

944Play

Make sure your grounds are clean, first.

The connection at the sender was apparently a bigger problem on the early cars than series 2.

My guage bounces due to dirty contacts between the circuit board in the instrument cluster and the guage itself. It often pegs out, but a smack to the dash puts it right for a while. It was rock-solid (at one needle-width above center) for a couple months after I unplugged and replugged it into the cluster.