Devon Brady

Hey all, hope I can get pointed in the right direction of what to look for next on my truck. This is a 92 toyota pick up 4wd v6. The truck has been running up until a month ago. I replaced the fuel tank, fuel pump, and fuel pump sending unit/bracket just before having problems. The truck ran for about 20 minutes before dieing. Since then it starts and runs for about a minute before shutting down. After that the truck won't start until I let it sit for at least an hour.

I found that there was no spark coming from the coil and replaced it but that didn't work. A friend of mine told me that when a truck starts, stops and then won't run it is because of a bad igniter because when a bad igniter heats up it won't send power anymore. I purchased a used one because I could not afford the new part. That didn't work and my friend believes the one I purchased was bad as well. I was not convinced and purchased another with the same luck. I think there is a different issue altogether because of what I have found on the forum.

I have taken the time to make sure my battery cables are hooked up correctly and that all my grounds are clean and continuous. I checked the resistance on my distributor and that passed, air gap in the distributor, the rotor, cap, and spark wires passed as well. coil resistance was good because it is new, timing belt is new, fuses are good, relays are good, i opened the ECU/ECM and it is clean inside and is getting power, I have not checked any of the signals coming into or out of it yet.

On the dashboard my check engine light and battery do not light up but they have in the past, battery light sometimes flickers

To check the IGF and IGT the manual says the truck is idling. Is that true or is it possible to test this while it is not running?

Now I should go through each sensor going to the ECU as well?

Haven't done this 'tap' test yet: https://www.yotatech.com/forums/f2/n...89-95-a-10543/

Devon Brady

I am posting my solution for someone in the future who has a similar problem. My circuit opening relay was getting a steady stream of water on it whenever it was wet outside. it was rusted out and the diode was not attached anymore. getting a new one was necessary but did not solve my problem, my check engine and battery lights were still not coming on. I looked at my fuse panel on the driver side. with my key on I checked the ignition fuse and when i replaced it into the socket I heard a click that was the opening circuit relay I was hearing. I found that the ignition fuse had to be inserted into its socket and pressure applied to one side to get power through the fuse and in turn get the relay to stay open. This brought back my check engine and battery light as well. The truck started right up and keeps running.

If the truck is running and that fuse gets 'loose' or pulled the truck dies. What I find strange is that if the fuse is put back in the correct position the truck will still not start for approximately 10 to 20 minutes, mimicking what some mechanics deem an overheating igniter. is that some kind of normal fail safe within the opening circuit relay/ignition system? i had read that the opening circuit relay is partially a safety measure if the vehicle got into an accident and punctured a fuel line so the vehicle didn't keep pumping fuel out onto the road. does the relay or some other part of the system keep the vehicle from starting for this period of time under the conditions I described? Good luck everyone

RAD4Runner

Key in "ON" position or "START" position?
C.O.R. will not click with ignition switch in ON position, only in "START" position. This is to get fuel pressure ready for ignition.

Need to have pressure applied is obviously a problem. Did you correct it?
Relay to stay Open? When C.O.R. gets power, its contact closes to turn on fuel pump, not open.

Correct.

I highly doubt it. C.O.R. is ready to turn on when power is applied to it.
You gotta take care of your loose fuses and connections issue and get them over with, , else you'd be left guessing all the time.