[allenflight2]

I have a 84' p-type that sat for 10 years, trying to get it to run for the first time. so far ive put a new battery, battery terminals, spark plugs, plug wires, vacuum hoses, slave cylinder, fuel pump, fuel filter, efi main relay #1, and ive cleaned the injectors and fuel tank. It runs off of ether and has good fuel pressure in the rail. the injectors aren't getting power so i checked the ign fuse, efi relay #1 and #2, which they seem fine and click. when i put the intake back on i rerouted the injector ground harness to the front stud on the intake which i believe is a good ground. im wondering if its my ecu?

 

[AJ]

EFI fuse #13 under the hood??

Reset power circuit breaker left foot well??

 

[Jeremy R.]

Check for cracked insulation on the wiring harness too. Maybe one of the injector wires is shorted or grounding out.

 

[pdupler]

Dale posted some good injector circuit diagnostics once upon a time.

Injector circuit troubles

Injector circuit troubles. I recently put a 6m in my car using all the old 5m parts that were running the car before, everything ran as it should with the 5m in it but that has been 6 months ago. The 6m got a full rebuild. Having trouble getting the car going since the engine refresh. When I...

www.celicasupra.com

 

[supra_toy]

put the injector ground back to original spot... There was a good picture showing it's location around here somewhere...

 

[supraz]

Engine Compartment Ground Locations

 

[dannoxyz]

Greetings & Salutations!!! 👋

...
the injectors aren't getting power so i checked the ign fuse, efi relay #1 and #2, which they seem fine and click. when i put the intake back on i rerouted the injector ground harness to the front stud on the intake which i believe is a good ground. im wondering if its my ecu?

Don't do that, you'll fry your injectors, ECU, entire wiring harness and perhaps ignite fuel pump in tank and cause minor explosion.

Follow wiring diagram religiously.

• injectors are NOT connected to chassis-ground anywhere
• injectors have fulltime power any time key is ON
• ECU momentarily grounds injectors to fire them

Connect oscilloscope to ECU injector wires to verify they are being triggered by grounding pulses. Injector harness is HIGH (fully powered up) most of time, then goes LOW when grounded by ECU, 5ms pulsewidth shown below.

 

[pdupler]

Surely our OP was just talking about relocating the A4 grounding lug on the engine wiring harness, not re-wiring it, but hopefully he'll return and let us know how he's progressing. Should be enough detail here to either figure out the problem or rule out electrical issues.

 

[dannoxyz]

Yeah, more details on what exactly he's doing.

A4 has ECU ground. But injectors should not be connected to it.

ECU lines 10 & 20 are what grounds injectors

 

[allenflight2]

thanks for all the feedback! turns out the efi resistor wasnt plugged in haha. it runs now but has i think a fuel pressure problem because when i gun it after its warm it bogs down, it gets worse the longer the drive. also no i did not rewire the injectors, i just moved what i thought was the injector ground thats normally on the bottom, second from the front, intake bolt, to the front top intake stud because it was easier to deal with

 

[allenflight2]

EFI fuse #13 under the hood??

Reset power circuit breaker left foot well??

power circuit breaker? im unfamiliar