929 misses when it warms up

[TLBLZER]

I have a 1992 929 and the problem I am having is this.When you first start the car it will run like a charm for 15 minutes or until it warms up i should say and it starts missing and running like crap.Does anyone have any suggestions for this. Thanks

[rhandwor]

I had a 1994 929 and the voltage to the pickup in the distrubutor was the problem I checked it with the plug disconnected and it was perfect. I paid an electrical shop $350.00 and he kept it 3 days changed the distributor. The problem occured about 30 min. from the shop he didn't know anymore than I did.I bought a new car as my wife wouldn't drive it any more. Once I had the pressure off I found the problem. It would drive perfectly for a while and start shaking getting close to a stall.
I made a connection so I could monitor the voltage at the distributor and it was 6 volts because it changes back and forth,and then down to zero then back up. I ohmed the wires and couldn't find it. I purchased a few feet of shielded cable and ran a new wire from the computer to the distributor, grounded the shielded cable this cured the problem.
I had to purchase a factory manual and wiring diagram. You can purchase cheaply on ebay.
They don't sell electrical parts for the dist. You have to buy rebuilt or junk yard. You can clean the idle air valve. Ohm the spark plug wires very expensive.
Missing do you mean rough idle or does act like it loses voltage. Very important difference.
Also check the crankshaft position sensor when unplugged it should go from zero to one when cranking.