Here's my problem...i need help quick. I'm in the middle of swapping out my 89 tbi setup for an 88 TPI setup. When we layed the 2 wiring harnesses side by side, we noticed that the TPI harness has a fuel pump relay and fuel pump boss primer plug (that's what it's called in the haynes manual), and the TBI setup didnt. This means that the plug on the TPI harness has nowhere to plug into. So how is the fuel pump going to come on? I'm thinking that maybe the plug is something that can be bypassed, or i'm going to have to splice the wires off that plug into the wires leading to the fuel pump. What I dont get though is...how did the TBI pump turn on if it didn't have a fuel pump relay?? It had to have some other method. If anyone knows anything, help me out...thanks

 

The 89 TBI does have a fuel pump relay. I don't know what you're talking about on your "fuel pump boss primer plug". What page on the Haynes manual is that mentioned on?

Maybe you're talking about the test connector? On the 87 harness (identical to the 88 I'm sure), the test lead was included on the motor harness which eventually wound up on pin G on the ALDL connector. On the 89 TBI, I believe it's on the "body" harness, which is why it didn't come out with the motor harness.

Or maybe you're talking about the little 6 pin/3 wire connector that has the injector power wires on it.

Are you also making sure the IP connector is matching up? The 89 doesn't have the injector power plug, they moved those wires to the IP connector (that's the clear 15 pin connector near the ECM connectors).

This is all based on my experience with an 87 harness though. Yours may be a bit different. Makes me wish I just had an 89 TPI harness.. chuckle.