I have a 1988 V6 toyota pick up, standard transmission. She starts up on the first try when the engine is cold and runs great as long as she’s still running. The problem is when I turn her off when i get to home depot or wherever and try to start her up 20/40 minutes later she won’t start. She cranks, sometimes will almost start, but I’ll end up draining the battery trying to get started. Usually have to wait 1/2 hours and then starts up no problem again. I’ve tried doing general maintenance (spark plugs ect.) and replacing the crank sensor at the advice of my mechanic, but at this point he’s stumped. Can anybody help me??
The problem might be vapor lock.
To find out, carry a bottle of water in the truck. The next time the engine doesn’t start, open the hood and pour the water over the fuel rail.
If the engine starts, that’s vapor lock.
Does it have distributor? 4 cyl or 6 cyl engine? There’s an ignition control module in some of those distributors. The 4 also has a pickup coil in there. Those are heat sensitive and can fail in the way you describe. Opening the hood while gassing up or on a brief stop may make enough difference for a while anyway. Is there really a crankshaft position sensor AND a distributor?
If testers trick doesn’t work, next time pour the water on the coil and try it.
Something else you can do … for info gathering purposes. Have a can of starting fluid handy when you expect the no start… give her a little zap with the fluid and report back the results.
Another little trick… this is for fueling problems/suspicions
At your air filter …the large hose coming out of airbox going to intake… there is your MAF… but in your vehicle it is more than that… it has a door inside of it that is directly in the airflow… how much the door moves indicates to the engine how much air is being inhaled and thusly… how to pulse the injectors for fueling
With the engine off and key on… prop that “air door” open with something like a piece of wood… this will cause your fuel pump to run constantly… instead of it only priming amd then shutting off and waiting for the tach signal.
See if this helps it to restart… you can open the door wide to verify the fuel pump is running constant… it must run when this door prop is in play
You can prop the door much less open…as in a half inch or one inch… and try to start the engine. Be sure your prop cannot be sucked into the hose…
Report back whatchagots…
If this is a new problem it could be your fuel pump is getting weak. Your engine is fuel injected, right? A weak pump can cause vapor lock.
I have an '87 4-cylinder, carbureted. The fuel pump (mechanical) gradually weakened over the course of years then stopped working altogether. I didn’t have this symptom. I bought a new one for $27 from the Zone of Auto. Except for breaking the temperature sender gauge in the process, it would have been easy to replace, certainly cheaper than taking it to a mechanic.