abramsjw

I'm reaching out to the forum community in desperation after trying all I know to do.

- Truck will run with fuel being squirted into intake by hand (or off starting fluid).
- Injectors not pulsing on the non-red side.
- Good voltage to the red side of injectors.
- Good ground to pin 60 of the EEC Module.
- Good connectivity from pins 59 & 58 of EEC Module to non-red side of injectors.
- A probe of pins 59 & 58 of the EEC Module do not show an on/off (pulse) of ground while turning the engine over.

Thoughts?

abramsjw

I should have noted this part.
- 5.0L 302 gas motor
- Was running fine, just quit, so, I'm suspecting something electrical that causes the pulse to the injectors.
- I have wiring diagrams from Haynes manual.

abramsjw

"Rnlcomp" suggested the the pcm (which I assume is the same as the EEC Module as far as this discussion goes) does the pulse width modulation of the injectors. Yes, I agree. I have replaced the EEC Module with no change in symptoms. Is there a sensor that could be telling the EEC Module to not generate the injector pulse? Also, I'm using a multimeter, but is there a better tool to use to test for the injector pulse?

greasyknuckles

did you change the module on the distributor? that would be called the TFI
module and is for spark. pcm is located either under the dash by park brake
pedal or on inner fender. it's been too long since I worked on one.

abramsjw

@greasyknuckles:
Yep. I replaced the module that plugs in and bolts to the distributor even though I probably didn't need to since getting spark out to the plugs is fine. What I didn't do, and I have a nagging thought about this, is replace the part that the module plugs into. You know, it's curved, tan colored, and you can see it when you look inside the distributor. I wonder if that part is important?

abramsjw

Update. I put a meter on the diagnostics port and the code I got was 22 (near as I can tell, kinda hard reading needle bounces on an analog multimeter). The Haynes manual says 22 (o,r,c) = a MAP Sensor Code and means "Sensor signal out-of-range". Whatever the heck that means.

abramsjw

Update. The MAP sensor, the one that was throwing the code 22, talks to the PCM to control fuel delivery. More info to come once I replace the MAP sensor tomorrow.

greasyknuckles

no don't replace that part in the distributor it is for spark. I don't think the map
sensor is what your after either, I replaced a bunch of them if I remember it
was for idle issues as they would get water in them

abramsjw

I replaced the MAP sensor (like the code 22 said to do). All is well! Truck starts and runs great! Problem resolved.

vjsimone

Hey, send me your old MAP sensor........ like to make some measurements;;;