Hard to start after sitting when warm.

[PK 77 911]

77' 911s 2.7 L. Still fighting with this issue. After car is at full op temp, When I turn it off for around an hour it takes many many cranks to get it to start. As soon as it does fire, it chugs a bit then smoothes out. I beleive it is a fuel pressure issue.

I have replaced the accumulator and the injectors and tested the fuel pump. Where else should I be looking.

Thanks
PK

[Oracle]

That sounds like a vapour lock but after reading other posts I learned that the other components can give silimar results, like WUR or fuel distributor or even an air leak, I hate to be the one saying this but keep searching.. I'm sure you'll come across someone who found the solution.

I have the same problem but I'm not too concerned anymore cause I know that if I lift the contol plunger in the fuel distributor I can purge the fuel system then I can restart the car.

-Jasper

[bigchillcar]

pk,
this problem is discussed over and over and is commonly attributed to one of two components of your cis setup: the accumulator or fuel pump check valve..in either case, failure of either means a loss of fuel pressure after a hot car has sat for a little while. since you have replaced the accumulator, i'd suspect the check valve..
ryan

[DavidI]

What Ryan said.......

Good luck, David

[Nitrometano]

Hard starting problem when the engine is warm can be the WUR. The easy way to check it is warm the engine to their normal temperature. Shut off the engine and try to start it. If the engine does nor start. Put a rag, towel or an old t-shirt wet it with cold water. Let sit the rag or t-shirt over the WUR for a few minutes adding water to cool down the WUR. Then try to start the engine. If the engine start you have a bad WUR.

[unclebilly]

Nitro - that sounds like a good idea.

I've had this problem with my car for a while now.

I've replaced the fuel pump twice, the accumulator, and one injector (it looked like it was leaking where the line from the distributor goes into the injector). I disassembled my WUR and it was spotless inside (it had also been recently replaced prior to me getting the car). I've looked inside the fuel tank expecting to see rust particles but it is like new so I don't have debris in the tank causing problems and when I changed the fuel filter, the old one was clean.

I did get a used WUR from an Audi that I plan to try (also with 22 ohm resistance) if the problem continues.

By the way, Jasper - if you need an accumulator, call Auto Value in Forest Lawn, talk to Jody - mine was ~ $125 tax in and it was the factory Bosch unit. They take less than 10 minutes to swap out.

[Nitrometano]

The ohm resistance test is another way to test the WUR. And works.