starting/stalling issues

[grngt50]

Hey everyone,

I had a thread going a while ago regarding my 94 GT's no start problems. Well, long story short.......mechanic found my injector harness to be toast and replaced.........all was well on the drive home. Since then the car has stalled on me like 12 times (Everytime it stalls the tach bounces up and down crazy like then dies). Now it wont start again.........injectors are NOT pulsing. Here is a run down of what has been changed.......

1.) ICM
2.) Reman'd dizzy
3.) Cap
4.) Wires are Ford racing almost new
5.) Two different coils
6.) Unplugged the MSD 6
7.) New harness

Things left to check, let me know if these would be a step in the right direction

1.) Engine/Battery grounds
2.) CCRM
3.) EEC


Please someone help me out! I need a reliable car for my kids/work/school!

-James

 

[HISSIN50]

Check that you have key-on 12 volts to the injectors.

If you have it, check for spark.

If you have 12V to the injectors, spark and still no inj pulsing, check that the TPS is below 3.7 volts.

If you had 12V to inj, no pulse and no spark, the PIP or TFI are likely bad.

 

[grngt50]

ok just DC'd the MSD6 again and car fired up 20 times in a row; Had rock solid idle for over fifteen minutes! I'm hoping this is it!! Apparently I had two seperate issues, that's why it was hard to diagnose..........the first being the injector harness, then the MSD box. Is it possible the injector harness that shorted out torched my MSD too?

And as far as the noid light test......I didn't know you had to actually crank to check for pulse.....I though it was key on only test..........and yes I know I'm a douche!

Later,
James

 

[HISSIN50]

Injectors get key-on constant power and then the EEC modulates ground to each one - it's easier for the EEC to modulate ground and it creates fewer issues if there's a short to ground. The EEC looks for a PIP signal when firing injectors, hence why the engine needs to be cranking when you use a noid light.

Though I would not expect the box to fry from a short (a shorted injector harness should ground individual injector drivers or short VPWR to ground), given how finicky some boxes are, the grounding scenario would not be out of consideration. The first move whenever such an issue arises is to circumvent the box (I do it no matter what brand the box is. It's just a large variable and so easy to circumvent).

Good to hear you got it fixed.

 

[grngt50]

Injectors get key-on constant power and then the EEC modulates ground to each one - it's easier for the EEC to modulate ground and it creates fewer issues if there's a short to ground. The EEC looks for a PIP signal when firing injectors, hence why the engine needs to be cranking when you use a noid light.

Though I would not expect the box to fry from a short (a shorted injector harness should ground individual injector drivers or short VPWR to ground), given how finicky some boxes are, the grounding scenario would not be out of consideration. The first move whenever such an issue arises is to circumvent the box (I do it no matter what brand the box is. It's just a large variable and so easy to circumvent).

Good to hear you got it fixed.

the MSD was the first thing to come off the car when I had my initial stalling issues........but the car ran (Or didn't run for that matter) like chit either way. The main issue at that time was the injector harness. But yeah what a PITA to fix Thanks for all the sound tech advice bro!

Later,
James