https://extinctmotorsports.com/extin...-manuals-rave/

 

You don't have to have the instrument cluster but if you don't swap the instrument cluster with the other two the odometer will blink unless you turn off the blinking using a nanocom. You do need to turn on the ignition key to the run position and leave it there for about 20 minutes once you do the swap to let the IDM in the interior fuse box synchronize with the BCM

 

Hopefully I won’t have to do that…but that’s good to know.

If the temperature difference is true, what component could be interrupting it?

 

Well if the ECU is changing the relay signal based on temperature, that sound like programming. If however the ECU sends the same signal regardless but something downstream is not triggering then sounds like a bad cold solder joint.

 

Okay so I was able to do some testing on the car again today.

First things first, I got to the car and made sure to close and lock all the doors. I locked and unlocked the car a few times to reset things. Then attempted to get volts to the meter to check for the prime with the leads in the fuel pump plug. Turned the key to 2nd position and got nothing on the meter. So on a cold start I would not get a fuel primed.

I then got a spare battery and jumped it directly to the pump and it started pumping fuel. I got the car started and let it run for a good 5 minutes until the temp gauge stabilized in the middle. While it was running I was getting constant 14v to the pump plug. After reaching temps, I shut it off and disconnected the pump. I then closed all the doors and relocked/unlocked them and attempted to get a reading out of the plug. After it was warmed, I turned the key to position 2 and I got 12v on the meter for half a second maybe. Don’t think it was long enough to say it was sufficiently “priming”. However it was a very noticeable reading and fluctuation on the meter compared to the cold start attempt that had nothing. After this plugged in to attempt to hear the pump actually priming and i didn't hear anything (even had someone’s ear on it). But I was able to get a reading a couple of times after letting it run and cutting it off but each time was for less than the 2 seconds and it would only happen a couple of times and would only send a prime signal within like less than a minute of it running.

So with this, I looked through the fuel system wiring based on the schematic. I have continuity and a low resistance all throughout the car of 3 out of 4 of the wires in the plug the whole way up to the main plug to the ECM that controls all of this. The only wire that had a very high resistance was the green/black wire for the fuel gauge potentiometer. It had continuity and the fuel gauge works perfectly fine so I do not think it has anything to do with this.

So in conclusion I believe the problem to be the ECM lacking to supply the ground signal to close the system to energize the fuel system to prime the pump in key position 2 for the 2 seconds it’s supposed to. However, while cranking the ECM supplies sufficient power to the plug while cranking and while it’s running. It’s just lacking the 2 seconds.

I have a new Bosch CKP coming in tomorrow so I will switch that out again to see if it has any change. But I don’t think that it will because it runs fine while the pump is jumped. Also the inertia switch system also checks out good, because while it was running I pulled the plug on the switch and it instantly shut off and the hazards started flashing.

My potential solution to this is to hardwire in a toggle switch to the pump that I can turn on and off to prime the system before I try to start it since the ECM is not. I think it would work fine as the ECM and circuit is proving sufficient power to the pump while cranking and while running, just not for the 2 damn seconds.

I think this would be okay to do for a while. I just don’t know if I want to spend about $400 on new modules for 2 seconds of priming. That could then be more of a headache tryin to sync them together vs 30 min and <$20 fix. Or until I get tired of being a pilot of an airplane and having to toggle switches before take off and I just bite the bullet for new modules.