Noid says no signal fuel injection not working

[dotis]

I have a 86 Comanche, 4 cyl, 5 speed, runs when you pour gas in the throttle body, checked fuel pump, ok, checked signal with noid, no signal at all, what should I check next? :cry: This has been sitting not running for over a year, ran when parked.

[Eagle]

The CPS also controls the ignition pulse, so if it runs by pouring gas in, the CPS should be good. I guess I'd start by tracing the wiring back from the injector and check all connections for oxidation.

[dotis]

Thanks, that makes logical sense, that's what I'm looking for. The fuse box and interior was kinda moldy and moist, so I'm thinking maybe it could be the connections on the computor.

[carnuck]

Spray ALL the connections in the truck with electrical contact cleaner before throwing a CPS at it. You might save some $$$!

[traitor5150]

You can test the crank sensor. Also check the cam sensor.

[JeepcoMJ]

replace the fuel pump relay. that should be it. if not, you need to get a diagram and check the fuel system wiring to see what is wrong with it.

 

check pin number 21 on the ECU (light blue wire), that's the fuel injection control. also, pin number 6 on the ecu (oranche w/tr) is the fuel pump relay control. check those wires and see if they're there. If it's a connecter problem, those are it. spray the sh*t outta the pin connecter, but be reserved on the ECU (engine computer), as too much can corrode and damage the computer inside.

 

but those are what your problem would be...fuel pump relay, short in those wires, or a short in the relay wires. If it's not that, then your fuel pump is bad...in which case I have a basically brand new one here at home so let me know if you need it!

[JeepcoMJ]

 

here's a picture of the ECU connector view. it tells you what all the wires coming from the Engine control Unit do. so that should help if you know anything about wiring :D

[dotis]

OK, I found several problems in the wiring, the relay connections were major corroded, I replaced relays and sockets, still no good, replace the ecu now I have a good noid light signal, I can put the noid light on and pour gas in the intake it will start and the light gives a good signal, I am quite certain I need a fuel pump, still have a spare? what would be the cost?

[JeepcoMJ]

i should still have it, and it would be 40 bucks plus shipping...

[carnuck]

Depending on where you are, I have an '88 tank with pump in it for $50 (I'm in Seattle)

[dotis]

OK it runs now. The issues were as follows:

1. I knew it wasn't ignition, timing or speed sensor as it ran fine with gas poured into the intake.

2. checked injector signal with a noid light no signal

3. rang out wiring and found no voltage to injector

4. replaced relays and sockets (very coroded) got signal to injector

5. checked again with noid light still no signal

6. took out ECU rang out wires to it all ok

7. put ECU back in still no signal

8. replaced ECU now good signal, pour gas in intake runs and noid light is flashing as it should

9. took off noid light and hooked up as normal still no run

10. replaced fuel pump purrs like a kitten

 

SO... I had a combination of problems, but all solved and it runs great

Thanks to everyone for their help! This is a great list.