Hard to start when the engine is warm?

JB361800

MEMBER
1986 TOYOTA 4RUNNER
2.4L
4 CYL
4WD
MANUAL
220,000 MILES

I have the vehicle listed above with a 22RE engine. It will crank perfectly after it has sat, and the engine is cold. Once I crank it and the engine warms up, if I turn off the engine, it doesn't want to start back up until the engine has cooled down. I recently replaced the MAF sensor, cold start injector thermo time switch, ECU temperature sending unit, and the coolant temperature sensor for the gauge. None of these replacements fixed my problem. I can hear the fuel pump turn on when the ignition switch is turned on, and I can hear the circuit opening relay for the fuel pump making a "click" noise like it's supposed to. I am at a loss on what to check next. Any help would be greatly appreciated! Thanks!

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,967 POSTS

To me it sounds like the fuel pump is getting weak, but we should run the codes to see if any are stored.

Here is a link to show you how:

https://www.2carpros.com/articles/toyota-trouble-code-definitions-and-code-gathering-method-1990-1995

Also, we should check the fuel pressure and I need to ask if you have changed out the fuel filter recently?

Fuel Pressure
Engine idling, with vacuum hose disconnected from pressure regulator .................... 2.3 - 2.7 kg/cm2 (33 - 38 psi, 226 - 265 kPa)
Engine idling, with vacuum hose connected to pressure regulator .................... 1.9 - 2.2 kg/cm2 (27 - 31 psi, 186 - 216 kPa)
Residual pressure with ignition key off .................... above 1.5 kg/cm2 (21 psi, 147 kpa) for 5 minutes

This guide can help you will need to rent a fuel pressure gauge from the auto parts store to help.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

This guide may help as well:

https://www.2carpros.com/articles/comprehensive-guide-reasons-why-a-car-engine-wont-run-when-hot-and

Here is how to change the pump and filter out in case you need it. Check out the images (below). Please let us know what happens.

Images (Click to make bigger)