rb25 swap wiring issues.........................

[forum26]

its a s2 rb25 into a 91 gtst. When i first wired everything up it started and then would die seconds later. If i unplugged the maf and the tps it would idle just a little rough. Fuel pressure was about 40-42 psi at the rail vacuum pressure was -17 while idling. Voltages were correct on maf and tps while plugged in but car would not run with them plugged in. I figured a short somewhere maybe bcuase i could hear relays clicking while the key wasnt even in. Mainly the ECCS and IGN relays would just randomly start clicking while the key wasnt in the ignition. The next day the fuel pump just wouldnt work. It was working the night before while i was tryin to figure out if i had a short. The next day i get nothing at all from it. I checked again for shorts and according to my test light i had one so i started unpluging things 1 by 1 and pulling out fuses. No fuses were blown but while the ENG CONT fuse the IGN SW fuse and the MAIN fuse were in i had a short. I dont know whats on these circuts or if they conect but any one of those 3 fuses would cause a short if it was plugged in. Anyone have any ideas on what might be goin on here. There is a short but every single harness under the hood under the dash, in the trunk is unplugged and the ecu is unplugged, all relays unplugged only way to make the short go away is to remove all 3 of those fuses. Help please im completly lost on this. Also does anyone know if there is a main ecu ground on the engine harness or if its somewhere else. basically where does the ecu ground?


ps if someone gives me an idea that solves my problems ill seriously send em 50 bucks with paypal.

[Krazykouki]

sounds like you have something wired wrong with the ECCS system itself. If I where you, I would take both the wiring diagrams for both vehicles and compare them. I am sure you will see some major differences. Normally if the fuel pump is not working it is either not getting a signal from the ecu due to a fault with the CAS or improperly wired ECCS relay.

[forum26]

Yea ive been workin on this problem for the last 2 days non stop searching for a short or something. Just went out an plugged everything back in and redid all my grounds with new wires and added a couple grounds and what do u know...its running perfectly now. its always the last thing u try haha

[forum26]

only thing now is that my oil pressure gauge is not working. oil pressure sender problem?

[Krazykouki]

only thing now is that my oil pressure gauge is not working. oil pressure sender problem?

I'd check the resistance of the sending unit before I'd say it is bad.

[TheRBguy]

I have a rb25det oil pressure sending unit if you need one.