billplay

Bought the 87 951 in the winter.Has run fine.Now all the sudden since the weather has gotten warmer, she has developed a cough.
Starts and idles fine when cold..runs fine..heats up fine...never gets too hot.
But, when you turn her off hot..then restart after 10/15 minutes.. she coughs and hunts for idle..almost stalls.
Give her some gas and hold the rpms up for a few seconds and all returns to normal.
Any ideas????????????

H2Opumpr

leaky headgasket. Steam enters combustion chamber when metals expand. Then you have a bit of coolant slowly leaking in. Pools up when engine is off,restarting douses the flame, then idle recovers when all water vapor burns off. Off course this is worse case senario.

Bret 944

VERY possible. Also, my speed/reference sensors have less than perfect connections, and when it gets hot they have similar symptoms. If I jiggle them a little it stops.

The '84 (N/A) used to do that too, and I think its problem was a bad temperature sensor (I'm not positive on this though).

Good luck, I'd say head gasket is most likely, ESPECIALLY if it's never been changed.

awilson40

I vote on a leaky injector, mine did the same thing. Acted like it was on 3 cyl. When an injector leaks, it can allow a vapor lock situation that will smooth out when enough fuel has run thru the lines to purge any remaining air.

Troubleshooting hint...always check the simple stuff first

jurg

ok i think number 1 is the motive, but here some input
1-the engine temperature sensor is bad, or going bad- cheap and easy to replace,( the one under the manifold, with the blue top )
2 -fuel pressure regulator. test it with a gauge, or install an aftermarket one.
3-insufficient residual fuel pressure,- bad fuel damper
1 and 3 are the most likely ones though.
hope this help
Jurg