Is there a mechanic out there willing to HELP?!?

[Joeturtle]

I have an 89’ c2500 5.7 Tbi.
When I bought the truck I had noticed someone had their own Jimmy rigged wiring. I decided to clean it up and get rid of the excess wires. However, after doing so the damn thing wouldn’t start anymore. So the layout there was a blue wire plugged into the fuse box which ran through the firewall. Then was spliced into the alternator, and then was spliced into an aftermarket red wire, which ran along the back of the firewall, and finally spliced into the red and white fuel injector connector wires. I took it to a mechanic. He changed the distributor and said it had fuel pressure and spark and would run all day if you sprayed carb cleaner directly into the TBI system. However, when you stop spraying it, it would die instantly and it had no injector pulse. Anyone have any ideas of what it could be?

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[Komet]

Maybe no power to ECM. You should download the wiring manual and check for power on the relevant circuits.

 

[Hipster]

idk, sounds like whoever Jimmy rigged it had it sorted out better than you

 

[letitsnow]

Maybe put it back to the way that it was when you bought it, but buy some wire loom to put the wires in? These trucks are so old, it is not common to find one with all original factory wiring.

 

[RichLo]

So you have fuel pressure but no injector pulse, correct? Did you eliminate the oil pressure wire by any chance? The computer needs to see some oil pressure, I think its like 2 or 5 psi or something really low before it'll fire the injectors.

 

[PlayingWithTBI]

When you turn the Key On Engine Off, does the fuel pump run for 2 seconds? If so, the Fuel Pump Relay is working fine. The Oil Pressure Switch, on the China Rail near the distributor will turn on the Fuel Pump when it sees ~4PSI pressure but, it won't fire the injectors. Your ECM needs to see Distributor Reference Pulses while cranking before it'll fire the injectors. Check you wires going to and inside the distributor. There's a 4 wire connector going from the ECM to the back of it and a 2 wire one going to the coil. Inside the distributor is a 2 wire connector going from the ICM to the pickup coil.

 

[Erik the Awful]

You should have a constant 12v with the key on at the injectors. The ECM switches the grounds on and off to control the fuel flow.