Power to the coil but no spark at the plugs

Contour Enthusiasts Group Archives

I want to thank I8RICE & CHKNHWK for their efforts.

Power seems to be good everywhere except the plugs. The starter turns, the fuel pump kicks on but she don't start.
We checked all the fuses all are ok.
The PATS light seems to flash like normal.

Any other suggestions of things to check would be greatly welcome.

Thanks

There is a proceedure in the Haynes manual for checking the coil pack, but I don't have it with me. Somebody here should be able to give you the general resistance limits for our plug wires so you can check to see if those are at fault.

There is also a ground wire or TWO (so I've read) that attatch at the corners of the coil pack, make sure it/those are in place.

Sounds like you're almost there...

Thanks for the suggestion, we actualy did test the resistance in the coil it seemed ok. I'll have to check the grounds on the coil! I don't think we did that. Can't wait to get home and see if that's it.

Thanks again,

I can't remember for sure, but I think the coils are operated by switch ground on/off. If you have power to the coils and no spark, check the crank or cam position sensor.

Originally posted by tucker:
I can't remember for sure, but I think the coils are operated by switch ground on/off. If you have power to the coils and no spark, check the crank or cam position sensor.

That ground kinda sounds like the the problem, we tried cam position sensor. Will have to look into the crank sensor.

Thanks for the info,

Well the ground was ok, still doesn't start.

i would start at the plug wires...just a thought.

I dont have the wiring diagram in front of me, but basically you'll need to confirm that your getting a pulse on 3 of the wires that go into the coil pack. When you say you have power on the coil pack, I assume you've measured one or more of the input wires. The next question is weather you get a voltage change on any of the wires when the car is cranked. It's these pulses which are greatly 'stepped up' by the coil pack creating the high voltage to fire the plugs. No input pulses, no output. Hope this helps, I'll dig out my manual when I get home to see if I can provide some measurement points and expected measurements...

Originally posted by tw0wheelin:
I dont have the wiring diagram in front of me, but basically you'll need to confirm that your getting a pulse on 3 of the wires that go into the coil pack. When you say you have power on the coil pack, I assume you've measured one or more of the input wires. The next question is weather you get a voltage change on any of the wires when the car is cranked. It's these pulses which are greatly 'stepped up' by the coil pack creating the high voltage to fire the plugs. No input pulses, no output. Hope this helps, I'll dig out my manual when I get home to see if I can provide some measurement points and expected measurements...

We did test the C1, C2, C3 wires while cranking, I don't think they pulse. I have power to the four wire when the key is in the on postition. I also read something about the TP sensor that may cause the car not to start, I'll try to check that out tonight.

Thanks for the help,

hey brian i have a tps at home from my stock throttle body i know it won't let your car idle nice since the regular 2.5 and the svt throttle bodies open different but it should let your car start if your's is bad give me a call and we can give it a whirl

Originally posted by I8RICE:
hey brian i have a tps at home from my stock throttle body i know it won't let your car idle nice since the regular 2.5 and the svt throttle bodies open different but it should let your car start if your's is bad give me a call and we can give it a whirl

What I read said something about the throttle position may cause the car to not start. I don't think we tested that theory. I would need someone to move it as I try to start the car, OR invest in a remote start switch. A babysitter tonight would also help

...

And today is the first day the Mustang has seen rain in over 3 years!!!! I need new wipers.

I am hoping to get the tour running before we see SNOW!!!

Originally posted by Checker'd SVT:

Originally posted by tw0wheelin:
I dont have the wiring diagram in front of me, but basically you'll need to confirm that your getting a pulse on 3 of the wires that go into the coil pack. When you say you have power on the coil pack, I assume you've measured one or more of the input wires. The next question is weather you get a voltage change on any of the wires when the car is cranked. It's these pulses which are greatly 'stepped up' by the coil pack creating the high voltage to fire the plugs. No input pulses, no output. Hope this helps, I'll dig out my manual when I get home to see if I can provide some measurement points and expected measurements...

We did test the C1, C2, C3 wires while cranking, I don't think they pulse. I have power to the four wire when the key is in the on postition. I also read something about the TP sensor that may cause the car not to start, I'll try to check that out tonight.

Thanks for the help,

a bad TPS would not cause a no spark condition

the coil is fired off the crank sensor if the coil is good change the crank sensor and then if that does not work check the wireing for a short

Originally posted by lobudgetraceing:

Originally posted by Checker'd SVT:

Originally posted by tw0wheelin:
I dont have the wiring diagram in front of me, but basically you'll need to confirm that your getting a pulse on 3 of the wires that go into the coil pack. When you say you have power on the coil pack, I assume you've measured one or more of the input wires. The next question is weather you get a voltage change on any of the wires when the car is cranked. It's these pulses which are greatly 'stepped up' by the coil pack creating the high voltage to fire the plugs. No input pulses, no output. Hope this helps, I'll dig out my manual when I get home to see if I can provide some measurement points and expected measurements...

We did test the C1, C2, C3 wires while cranking, I don't think they pulse. I have power to the four wire when the key is in the on postition. I also read something about the TP sensor that may cause the car not to start, I'll try to check that out tonight.

Thanks for the help,

a bad TPS would not cause a no spark condition

the coil is fired off the crank sensor if the coil is good change the crank sensor and then if that does not work check the wireing for a short

I'm at the point that I think it is the wiring. This all started from replacing the battery and finding the 4 main power fusebox wires corroded.

Anyone know of a easy way to test the wiring harness? Or is there a tool that can be plugged inplace of the PCM and run tests? I don't think my multimeter leads are long enough to reach around to test both ends.

Thanks for the help.

This sounds like my problem....

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=286887&Forum=CatSearch-1&Words=computer%20code&Match=Entire%20Phrase&Searchpage=0&Limit=100&Old=allposts&Main=139635&Search=true#Post286887

Additionally, with a Wire Diagram and multimeter, you can check the continuity of the wires from the harness to the final destination. That may help you diagnose the problem.

Good luck

Originally posted by zgendron:
Additionally, with a Wire Diagram and multimeter, you can check the continuity of the wires from the harness to the final destination. That may help you diagnose the problem.

Good luck

Doesn't that just sound like fun.... I was hoping there was a tool or easier way. There are alot of wires coming out of the harness. Lucky I have a tone genterator that may help track down the wires. I know the book and the car wire colors don't always match.

I8RICE & CHKNHWK up for some wire tracing excitement???

Thanks for your help,

I am up for anything man as long as we get your car back on the road, so we can go have some fun ripping aroud the twisties chasing eachother.

dont lock the thread. anyway, checkered when you find out which wire(s) it is let us know, becuase it sounds kind of like what has happened to me in the past, and i want to know if it will happen agan (was 120 bucks for mechanic to trace, then 250 dollars to replace wiring harness, i know i got reamed on that one *cough* damned dealers

) anyway, let us know.

Well I found out there is a diag tool called a breakout box. That does indeed plug in between the PCM and the car, but they cost around $500. But it gives you easy access to the pinout in the cable with a multimeter & enough cable to work under the hood. Anyone have one I can loan?

Sorry for the SSL but my ISP blocks port 80...

Otherwise I8RICE & CHKNHWK are you guy available tonight??? I need to make longer multimeter leads & have extra hands. Oh and you guys better finish the beer this time...

I MIGHT BE ABLE TO MAKE IT TONITE FOR A BIT

Originally posted by I8RICE:
I MIGHT BE ABLE TO MAKE IT TONITE FOR A BIT

Cool I should have the power cable from Ford.

Originally posted by Checker'd SVT:

Cool I should have the power cable from Ford.

Looks like the wrong cable..... go figure.

Reordered the cable "KIT" which of couse has more wires then I need... But is the only why to get the needed cables.

Correction the "KIT" is the cable(s) I need and it only costs $160.00 yeah.... Now to reorder the frist cable the was suppost to be in the "KIT".