I have an '87 gta that had an original 350 tpi. I've swapped it to an '89 tpi 350 motor, now the fuel pump wont work!
any ideas? are there any change overs i have to do?
I've switched the '87 harness to the '89 as well now, and no luck.
I'm stumped. I'm just wondering if there is anything else i should have done. I have the '89 ecm put in along with a vats delete eprom. someone help!!!
thanks 87GTA57L

 

Did you get the relay and is it plugged in?

 

If the fuel pump isn't coming on it should be a simple matter of tracing the circuit to figure out why it's not getting power. If you swapped wiring harnesses i assume you're familiar with the concept of electricity.

 

Are you running the 89 chip in the computer? The 89 chip has VATS turned on, but your car doesn't have VATS. The result... no fuel pump power in addition to other things.

The fuel pump circuit is identical on the 89 vs 87. In fact, I'm not sure why you even swapped to 89 stuff to begin with. The only single difference between the two is that the 89 eliminated the cold start injector.

 

Jim you're the man


I was sitting here tooling over what the heck the change was in 89, I knew what it was but couldn't think of it, spacy :lala:

Anywho that should be it (unless you're using the 87 memcal, in which case )

 

thanks for the replies guys....keep'em coming!
some people are telling me that vats doesnt interrupt the fuel pump...it interrupts other things like the starter. on second hand,
I have a vats delete eprom, that theory is now gone!
are there any pin connector changes like on the junction box on the firewall or on the ecm that need to be changed? I know you guys can figure out my problem, you guys have taken me this far!
anyhow, hope you guys can help!
87GTA57L

 

try jumping the fuel pump relay to make sure the wire from the relay to the FP is good. Also would help if you make sure the relay wors too. If that checks out, then yes, it is likely that you missed or misplaced the fuel pump relay enable signal from the ECM to the FP relay. Don't know the wire colors or pin numbers offhand, but if you just swapped harnesses you probably have a schematic handy.

OK, just remembered i posted the relevant piece of the schematic in another post recently.

If you don't have BA11 going to the FP relay, therein is your problem.

BTW, you are correct in that VATs doesn't disable the fuel pump, it diasables the starter relay and injectors. And you have a VATS delete chip anyway so...

 

Just for ****s and giggles i had the same problem with a fuel pump not coming on and i went through the whole process of replacing it and when i tried it still didnt work..... But check behind the battery on the passengers side for a fuse running in the fender. I believe it is a fuel pump fuse of some sort but i replaced it bc it was blown and the pump came right back on. Not saying this is your problem but i would check it just for the hell of it.

 

That's the ECM fuse, and if the ECM doesn't have power, it won't turn on your fuel pump.