Make a sharp turn = no spark...WTF???

[MadPSI]

Upon driving home two days ago I turned the steering wheel to full left lock and the truck instantly died. After straightening the wheel and waiting a minute I got it to fire up long enough to pull it in the driveway. The truck hasn't started since.

After some preliminary testing, I've found out that the truck doesn't get any spark at all. I took the coil wire off the center post of the distributor and put a spark plug on it. It got absolutely no spark while cranking, but it shocked the crap out of my buddy when I turned the key off.

I did a lot of other tests on most of the plugs going to the coil/ignition module/etc., but I didn't really know what I was looking for or what the voltages were supposed to be on each pin at at what time...

My buddy took my ECM out and replaced the chip with the stocker, but I think we're barking up the wrong tree here...

Is there some wire up in the steering column area that could have possibly come undone from turning the wheel? Has anyone ever had this problem? I'm going to continue to dig in that area, but it would be cool if someone knew "The xxxx wire needs to see +12VDC while the truck is running...".

Thanks...

 

[dgoodhue]

Re: Make a sharp turn = no spark...WTF???

I don't see how turn the wheel would afect it, but the ignition switch at the bottom of the steering column could be defective. My old Typhoon had problems with it and it wouldn't crank sometimes, before I cleaned it. (The problem came back though and I had to clean it again, so I probably should have repalaced it)

 

[MadPSI]

Re: Make a sharp turn = no spark...WTF???

I'll give the switch a shot. The motor cranks just fine, it just doesn't get any spark.

 

[93ty475]

Re: Make a sharp turn = no spark...WTF???

try the coil to distributor harness.... the pink/white wire one with a plug on each end.....had that go bad on me once....drove me nuts.....

edit: more specifically, I had to push one of the wires into the plug to get it to start....as if it had become de-crimped where I couldnt see it.....

 

[93ty475]

Re: Make a sharp turn = no spark...WTF???

And if it's not that...... this coil test should help you figure it out....

 

[tippmann243]

Re: Make a sharp turn = no spark...WTF???

ignition module

 

[bizkit]

Re: Make a sharp turn = no spark...WTF???

:stupid:

 

[MadPSI]

Re: Make a sharp turn = no spark...WTF???

ignition module

I didn't want to hear that, but I've kinda been leaning towards that possibility... Do they go dead that instantly?

Another find after trying a few more things today. The coil pack is getting BLAZING hot, too hot to touch. I'm hoping that a short in the ignition module is causing that and replacing it will fix everything. We'll see.

 

[MadPSI]

Re: Make a sharp turn = no spark...WTF???

It was the ignition module.

Replaced it just now, truck fired right up.

 

[gkrcr882]

Re: Make a sharp turn = no spark...WTF???

good to hear that your trucks' back in comission!:tup:

 

[tippmann243]

Re: Make a sharp turn = no spark...WTF???

It was the ignition module.

Replaced it just now, truck fired right up.

my 93 noma did the same thing, wouldnt start at a buddies house, got it started drove it home and then it died when i turned left into the driveway

plus ive done plent of them its fairly easy to diagnose

 

[QUICK STORM]

Re: Make a sharp turn = no spark...WTF???

good job, brandon

 

[MadPSI]

Re: Make a sharp turn = no spark...WTF???

Throw this valuable information into the vault!!!

turn left + truck dies = ignition module.

I was expecting the R&R to be a real PITA from other people's stories, but it was surprisingly simple. The only bad thing about it was that, upon removing stuff to get to the module, I decided to clean the 10+ years of crud that had accumulated everywhere else. Damn my anti-dirt OCD, next thing on the list is getting all the wires out of the engine compartment...

 

[myclone]

Re: Make a sharp turn = no spark...WTF???

Throw this valuable information into the vault!!!

turn left + truck dies = ignition module.

The key thing to put in the vault is when the truck suddenly dies and you have no spark 99.9% of the time its the ign module. The clues in the orignal post as to why it was the module are as follows.

No spark but his bud got the crap knocked out of him when he turned the ign off.
Reason: The coil had 12v applied to it constantly due to the ign modules internal circuitry being shorted. When he turned the ign switch off the 12v was removed from the coil and the magnetic field collapsed which generated a one time spark/high voltage that his bud got the pleasure of feeling. When working correctly the ign module alternately supplies then removes 12v from the coil each time the ruluctor ring lines up in the distributor which causes the magnetic field in the coil to alternately build up then collapse which in turn supplies the high voltage to the rotor, cap, plug wires, and finally the plugs. Since the module was shorted and applying constant 12v to the coil you didnt get a collapse of the magnetic field until the ign switch was turn off cutting the voltage to the coil which then collapsed the magnetic field and shocked the crap out of the poor guy helping (nothing like watching a bud get hold of the secondary side of an ignition to make you laugh or at least grin at him flailing around and cussing).

Coil was hot to the touch.
Reason: Ignition coils do not take kindly to a constant 12v being placed on them and they will get hot. With constant voltage the windings ignition coil is like a miniature heating element and will get hot. When operating correctly the 12v to the coil is switched on and off by the ign module so it doesnt get super hot just warm since the on/off action is happening pretty fast.

BTW, it was asked if ign modules normally just die all at once. Yes.... Ive replaced countless GM modules and all but one acted like you simply shut the ign switch off with no warning, sputtering, back firing, etc just...bam...dead. The one module that acted different actually caused the engine to sputter a couple times then it died but refired one time for a few seconds then died again permanently. Still havent figured that one out but a new module had the vehicle up and running like new after some trouble shooting and head scratching.

 

[MadPSI]

Re: Make a sharp turn = no spark...WTF???

HAH!!!

It was good times seeing Nick (nick041881) getting the crap shocked outta him... He equated it to being tazered. I don't know what it's like, but I can only imagine. He's one of those swollen weightlifter dudes, so anything that'll make him scream like a girl is funny.

 

[PPI Typhoon]

Re: Make a sharp turn = no spark...WTF???

HAH!!!

It was good times seeing Nick (nick041881) getting the crap shocked outta him... He equated it to being tazered. I don't know what it's like, but I can only imagine. He's one of those swollen weightlifter dudes, so anything that'll make him scream like a girl is funny.

:rotf: For the love of god Brandon, film these things next time!

 

[ThaJokr]

Re: Make a sharp turn = no spark...WTF???

:rotf: For the love of god Brandon, film these things next time!

Anytime those 2 get together to work on a syty they should film it. Something always happens thats hilarious.