Noob 960 question-hot start issue

racersd2 · Post by **racersd2** » 26 Jul 2009, 13:15

OK so i have done some searching. My stepfathers 1995 960 has a hot start issue. NO CEL, but he will run errands and turn the engine off come in say 5 minutes and then nothing it wont start wait 10-20 mins and then it will start. I heard something about a fuel check valve. Where is this valve? do I need to took at something else?

TIA
-Scott

Post by **billofdurham** » 26 Jul 2009, 15:42

Welcome to Matthew's Volvo Site.

For hot start problems check:
Fuel pressure.
Fuel injectors aren't leaking.
Ignition and all engine sensor wires are properly connected.
Spark plugs aren't fouled.
Ignition and coil circuits.
Throttle switch and connector.
Idle valve - ensure airflow arrow points in correct direction.

I haven't heard of a fuel check valve but it could possibly be the fuel pressure regulator which is located between the fuel hose and the fuel rail.

Bill.

DanR · Post by **DanR** » 26 Jul 2009, 22:00

Are you meaning it will crank but not fire up? Or it will not crank at all? Like a dead battery?

If it won't crank at all, then it may be the PNP switch, sort of neutral safety and gear sensor switch. The computer is sensing it is in a gear other than park.

If it cranks and just won't fire up, then it could be the fuel pressure regulator. It can go bad, allow fuel to be pulled into the manifold and makes things too rich for a hot engine.

DanR '94 964 343,000 miles (109,000 on the new engine)

FCPEURO · Post by **FCPEURO** » 06 Aug 2009, 13:55

A lot of times when you get a new hot start, it is the fuel pump relay. I would definitely look at that relay.