This has to be a stupid easy solution that I’m overlooking, someone school me on this please.
Truck is a 1987 (square body), with TBI. Truck ran and drove, transmission and transfer case were worn out, engine ran well but was leaky and dirty. Pulled all three, rebuilt transmission and transfer case, engine was resealed and replaced both oil pressure sensors, CTS for the ECU, and had a close to new distributor from my C1500 so I threw that in. TBI was rebuilt with Napa rebuild kit. Installed everything, finished today and tried to fire up, will just crank, no start.
Injectors are not pulsing, thus engine is not getting fuel. Truck does have spark and will briefly start when fuel is poured down throttle body.
Here‘s what I’ve diagnosed so far:
- Battery fresh off charger.
- Fresh fuel both tanks.
- Checked all fuses.
- Verified both pumps will run and build pressure at relay test port (both sending units work).
- Verified 12v at pump relay.
- Verified 12v at both injectors.
- Verified 12v at coil and at ignition module from coil.
- All engine harness grounds are connected at proper locations and clean.
- Cab to head, block to frame, frame to core support grounds are intact.
- Verified that injectors will pulse and spray fuel when ground is added.
- Verified that injector wires and ignition module wires all have continuity to ECM.
- Verified that all ECM grounds are good.
- Swapped ignition module with known good unit, no change.
- Wired in second distributor and spun with key on. Will spark, but no injector pulse.
- Checked ECU for damage, burnt components, bad solder joints, none visible.
- Swapped in known good ECU from my 1988 TBI Suburban, no change.
What the hell am I overlooking?
Truck is a 1987 (square body), with TBI. Truck ran and drove, transmission and transfer case were worn out, engine ran well but was leaky and dirty. Pulled all three, rebuilt transmission and transfer case, engine was resealed and replaced both oil pressure sensors, CTS for the ECU, and had a close to new distributor from my C1500 so I threw that in. TBI was rebuilt with Napa rebuild kit. Installed everything, finished today and tried to fire up, will just crank, no start.
Injectors are not pulsing, thus engine is not getting fuel. Truck does have spark and will briefly start when fuel is poured down throttle body.
Here‘s what I’ve diagnosed so far:
- Battery fresh off charger.
- Fresh fuel both tanks.
- Checked all fuses.
- Verified both pumps will run and build pressure at relay test port (both sending units work).
- Verified 12v at pump relay.
- Verified 12v at both injectors.
- Verified 12v at coil and at ignition module from coil.
- All engine harness grounds are connected at proper locations and clean.
- Cab to head, block to frame, frame to core support grounds are intact.
- Verified that injectors will pulse and spray fuel when ground is added.
- Verified that injector wires and ignition module wires all have continuity to ECM.
- Verified that all ECM grounds are good.
- Swapped ignition module with known good unit, no change.
- Wired in second distributor and spun with key on. Will spark, but no injector pulse.
- Checked ECU for damage, burnt components, bad solder joints, none visible.
- Swapped in known good ECU from my 1988 TBI Suburban, no change.
What the hell am I overlooking?