3.2 hor start problems!

[amschnellsten]

I have been having hot start problems on my 84 carrera. It starts instantly when cold but fluctuates to get an idle. When it is hot and sits for a bit I have to keep cranking and cranking until it fires. If I try to instantly restart it when it is hot it will start fine. I only have the problem when it sits. I have new reference sensors and cht sensor. It seems like it is vapor in the fuel. I did a search and found many people with similar problems but they were all 3.0 and it seemd to be the fuel accumulator. what could this be it is driving or not driving me crazy.

[DRACO A5OG]

Have you check your DME relay?

[amschnellsten]

I have not checked the dme relay. I am thinking that I actually replace it though when I had reference sensor issues last year.

[86 911 Targa]

Your DME is a good bet.

[DRACO A5OG]

If it is the DME ECU, take it out and check the solder joints. Steve Wong Posted what to look for and where to resolder the joints.

You need a good magnifying glass.

[ischmitz]

This sounds like your check valve in the fuel pump is bad and leaking. Heat soaking will cause the fuel in the rails on the motor to boil. That is why you have a hot start issue but it starts right up when cold or immediately after shutdown (no vapor buildup yet). The check valve helps keeping the fuel lines pressurerized so it won't boil.

You need a hydraulic fuel pressure gauge to check how quickly the fuel pressure drops when you shut down the engine.

Ingo

[amschnellsten]

where is the check valve? Is it in the engine compartment or on the fuel pump? thanks

[ischmitz]

My understanding is that the check valve is part of the fuel pump but I could be wrong. Maybe others could chime in here.

[amschnellsten]

I checked on the part and it looks like it is on the end of the fuel pump and looks like it can be changed. Is this right?

[kidrock]

that is correct, the check valve screws into the end of the fuel pump. It is made of cheap metal, and contains a small metal ball inside it's housing. Be very careful when screwing it into the pump, it is likely to break. Ask me how I know.

[DRACO A5OG]

Before you start throwing money on parts. Maybe invest in a pressure guage first.

I made a ghetto guage with parts from Home Depot and Auto Parts Store.

Cheap Air Pressure Guage ( the Fuel will kill the innereds, so one time use )
Clamp x 2
Fuel Injection Hose with ID to match the Fuel Pressure Test Port

I verified the pressure/Check Valve via Bentley Guide.

But hell if you are certain it is the Check Valve, it is a pretty easy access job. Liked said earlier do not over torque.

[amschnellsten]

I figure the valve is $ 20 and it seems easy so I will give that a try first. Where is the fuel pump?