racehoss

85 4Runner. Runs great but when it sits for more than 8 hours the fuel system has to build up pressure before it can start. A friend said it was probably the check valve in the fuel pump. I replaced the fuel pump and no help. After it was running fine I crimped the soft fuel line coming out of the tank and let it sit over night. Then uncrimped it and the problem was still there. What could it be?

tyrelephant

I know its been awhile, but did you ever find a fix for this? I have the same problem. im thinking fuel press regulator?

millball

Maybe no cold-start injector function??

SnapMech

I would check for a leaky injector or a leaky fuel pressure regulator if it uses a return system.

84sr5yoty

Try shorting out the fuel pump jumper connector with the ignition switch in the "On" position and let the pump run for 20 seconds or so before starting. If the engine starts immediately, it's a fuel pressure issue. If it doesn't, it's either a bad cold start injector time switch or a plugged cold start injector.

tyrelephant

ok, that makes sense. ive done the fuel pump jumper and let the pump turn on for 30 seconds before starting with no change. it doesn't seem to help. if I crank it a few times it always starts up eventually and runs smoothly once started. if shut off and then restarted within 4-6 hours it always starts right back up on the first crank. I recently had the upper plenum off to clean it out along with the cold start injector. the thermo time switch ive haven't checked. guess that's my next check. thanks guys.