Author Topic: Anyone got a spare HEI coil? (Read 1350 times)

Jamieg285 · « **on:** December 02, 2009, 11:05:00 pm »

I've developed an intermittent electrical misfire. Only happens when it's hot, and appears to get worse the warmer the car is. Symptoms are momentary loss of spark (tach needle drops, then bounces back up).

I've tried an spare ignition module and it's not that. I've got a spare cap and rotor to try, but I haven't got a spare coil to try. They're not cheap, so I don't want to buy one unless I've been able to prove that the current one is the problem.

It's the stock GM, in cap coil - anyone got a spare that I could borrow for a while for testing?

Jamieg285 · « **Reply #1 on:** December 02, 2009, 11:08:52 pm »

Also, if anyones got any suggestions on what this might be...

sixpack2639 · « **Reply #2 on:** December 02, 2009, 11:09:39 pm »

I can actually get a decent coil for $22 + tax....

sixpack2639 · « **Reply #3 on:** December 02, 2009, 11:12:13 pm »

Quoting: Jamieg285

Also, if anyones got any suggestions on what this might be...

Jamieg285 · « **Reply #4 on:** December 02, 2009, 11:16:40 pm »

Quoting: sixpack2639

I can actually get a decent coil for $22 + tax....

Hold that thought, I might go for that anyway. Always good to have a spare, especially at that price.

What about caps/rotors? Preferably black or blue.

sixpack2639 · « **Reply #5 on:** December 02, 2009, 11:33:11 pm »

Can't get you a price from Carquest today. They closed at 6pm. I can get an Accel cap & rotor kit for $23.99+tax in black from Advance.

Jamieg285 · « **Reply #6 on:** December 02, 2009, 11:40:38 pm »

I'll let you know in a few days.

Gator · « **Reply #7 on:** December 03, 2009, 06:56:13 am »

check all the leads i know its obvious but a spark can jump a fair gap

F Body · « **Reply #8 on:** December 03, 2009, 07:52:44 am »

Quoting: Jamieg285

Only happens when it's hot, and appears to get worse the warmer the car is. Symptoms are momentary loss of spark (tach needle drops, then bounces back up).

I'd go coil although have you tried changing the condensor

Fieldy · « **Reply #9 on:** December 03, 2009, 08:09:19 am »

Quoting: Gator

check all the leads i know its obvious but a spark can jump a fair gap

Mine was a mixture of both IIRC, coil and one spark plug....

Jamieg285 · « **Reply #10 on:** December 03, 2009, 08:34:34 am »

Quoting: Gator

check all the leads i know its obvious but a spark can jump a fair gap

Leads are only a year old and look in good condition. What should I be looking for?

I guess you'd be able to see any jumps in the dark?

Jamieg285 · « **Reply #11 on:** December 03, 2009, 08:34:55 am »

Quoting: F Body

have you tried changing the condensor

Is there one in a HEI system?

Jamieg285 · « **Reply #12 on:** December 03, 2009, 08:42:05 am »

Quoting: Fieldy

and one spark plug....

Not checked the plugs yet, not expecting to find any issues there though as it runs fine 99% of the time. (Although maybe 95% now, based on this mornings journey)

Roadkill · « **Reply #13 on:** December 03, 2009, 08:55:06 am »

Quoting: Jamieg285

I guess you'd be able to see any jumps in the dark?

Correct.

Sounds like the coil. I'd get a new one as opposed to one which may have been kicking around in someones garage for a few years . . .

That box of stuff at Carls will be shipping very soon.

Jamieg285 · « **Reply #14 on:** December 03, 2009, 09:50:51 am »

Quoting: Roadkill

Sounds like the coil. I'd get a new one as opposed to one which may have been kicking around in someones garage for a few years . . .

Just to clarify, I'm only looking to borrow for diagnostic purposes only. As soon as I can confirm what the problem item is, I'll get a new one. That said the prices Carl has quoted above are tempting to just replace the lot anyway.

Quoting: Roadkill

That box of stuff at Carls will be shipping very soon.

Should be timed pretty well for me then

Jamieg285 · « **Reply #15 on:** December 03, 2009, 01:59:57 pm »

Progress.... of sorts

While looking for the spare rotor (which I've not found) I found an old coil that I thought I'd chucked, still attached to the spare cap.

Swapped them over quickly this lunchtime and the issue has gone away. The problem now is the coil is weak and I can literally feel the drop in power from the old coil. Still at least this one doesn't keep stallling on me!!

That narrows it down to cap or coil. When I next get a few mins (and it's dry) I'll swap the coils over to get the final answer (I hope)

Jamieg285 · « **Reply #16 on:** December 04, 2009, 09:11:51 am »

Bugger it.

Now I remember why I swapped out this coil in the first place. Is so weak it barely starts the car in the cold mornings. In general, I'm lucky if it will start without draining the battery to a point where I've got to hook up a charger.

Took 5 mins to start it this morning. Might have to dig the bike out of the shed for next week.

Jamieg285 · « **Reply #17 on:** December 07, 2009, 08:32:28 am »

Nope, totally confused now.

I've tried every combination of cap/coil I've got, even back to the original ones that had the problem and it's all running fine now.

I'm wondering if there was a loose wire that I've fixed without knowing it.

Fieldy · « **Reply #18 on:** December 07, 2009, 08:46:44 am »

Odd, but good

Roadkill · « **Reply #19 on:** December 07, 2009, 08:58:42 am »

The problem may well resurface.

I'd been inclined to get a new cap and coil ordered as soon as possible as you now there's obviously an issue, there, somewhere.

Jamieg285 · « **Reply #20 on:** December 07, 2009, 09:06:41 am »

Quoting: Roadkill

I'd been inclined to get a new cap and coil ordered as soon as possible as you now there's obviously an issue, there, somewhere.

I would too, but money's too tight right now to just get stuff I don't need.

I have no doubt that it will resurface the day Carl has sent the box of stuff though.

Jamieg285 · « **Reply #21 on:** December 07, 2009, 09:07:27 am »

+ I've proved that I have enough spares to keep my running (of sorts).