Wont restart after warm up

[83911]

I have an 83 3.0 that starts and runs perfect when cold. After the car warms up and I shut it off it will only crank and turn over but not start. If I leave it sit for 15-30 minutes depending on temperature it will fire back up and run perfectly. I started it this morning and ran for 10 minutes shut it off and it would not restart. I let it sit for 10 minutes and it fired right back up. Any help or ideas will be greatly appreciated. thanks in advance for any help.

[SpeedracerIndy]

Sounds like you need a new fuel acculmulator. The accumulator prevents fuel from vaporizing in the fuel lines when the engine gets hot.

[RickM]

Yes, this would be considered a Warm Start problem. As Casey mentioned the fuel accumulator is a very common cause.
However, I'm surpirsed that after 15-30 minutes it starts fine. Usually this no-start symptom exist for a while longer.

[Don Dosmann]

My 78SC started doing this too. Changed everything,fuel pump, accumulator, cold start injector, nothing worked. until I richened up the
CIS a little bit. Your car starts when cold because the cold start injector
is adding gas to the system, once your engine is warm, the cold start injector doesn't work. Your engine relies on the throttle plate to raise during cranking to provide gas to the engine start. If your CIS is set a little lean, the throttle plate is raising, but not enough to let any gas into the intake system. Richen up the CIS about 1/4 turn and see if it starts,
Mine did and still does.
Don

[Mike Kast]

If you can't diagnose it yourself, I can't, I would find a mechanic to diagnose it for you.
It would have saved me a bunch of money if I wasn't so stubborn when I was having fuel problems. Change this and that and maybe this and that thing there isn't shiny enough, must need a new one.
I don't know enough about CIS to have an opinion about you problem, but the parts are expensive. I found if I had thought things through a little more I might have saved some money or I might not have saved any money. All the parts I changed might possibly have been bad, but I don't think that is likely. I'll never know.
Do you have receipts? How old is the accumulator?

Mine did exactly the same thing. It was the fuel pump check valve.

[sammyg2]

Your problem is classic to the CIS, it is due to the fuel in the injector lines boiling and causing vapor lock. CIS is designed to prevent this by holding pressure on the fuel lines long enough for the engine to cool down. If you lose pressure too fast the fuel boils.

A loss of residual pressure can be caused by a leaky fuel pump check valve, a leaky injector, or the fuel pressure accumulator. in my case it was the accumulator.
I replaced the check valve, no change (only $11, no biggie).
I replaced all the injectors, didn't solve hte problem but ran better.
i replaced the accumulator, problem went away completely.

Most people start with the fuel pump check valve cause it's cheap.
Injectors can be diagnosed by running the engine and after shutting it off pull the injectors out and watch for weeping. Caution, gas is falmmable and all usual precausions must be be taken to prevent fire damage or injury.

The fuel pressure accumulator is a bit harder to diagnose, earlier versions had a vent line that was routed back to the tank, later versions (two lines) didn't have this. if you have the three hose version you can take the vent hose off and watch for leaking. There should be none.

In the mean time you can get it to start by simply pulling off the air cleaner top and lifting the air sensor plate with the ignition on until you hear the injectors fire for a couple of seconds.
This clears the lines of vapor and will get it running.

[83911]

Talked to PM and he said to richen the mmixture on the CIS system. Will try that first before I start replacing other parts. Will keep you posted. Thanks for the replies.

[RazorRacer]

My car acted similar, but it didn't stop running. It would sputter under acceleration when warm. It turned out to be the vacuum advance on the distributor. I ended up just removing the vacuum advance unit and running with 13 degrees BTDC on idle.

[Joe Bob]

Check valve...cheap....it's under the banjo fitting in the neck of the fuel pump.