coil pack problems

[Gesex]

a few months ago i had the head gasket changed and when we tried to start the car up, the coil pack was dead. swapped out a new coil pack onto it, and the car started up fine.
well, the head gasket didnt seal so i put on another one the other day and the coil pack was dead again.

im gettting spark from the pack that runs the #1 & #4 cylinders, but nothing from the #2 & #3 (the middle 2 cylinders). I tried swapping out 2 other coil packs in the dead ones place, but still nothing.

I dont see all 3 of those packs being dead, so im assuming that my problem lies elsewhere. I am going to try to install a brand new coil pack when it comes in. if it works then hooray, but if it doesnt then i'll just return it and look for the problem elsewhere.

any suggestions on what else to check in case the new pack doenst work also?

 

[laserblue]

BTW... What's your make/model/engine/year?

Pulses to the coil packs come from the 'power transistor unit' which is located in a little engine block cubby-hole a few inches below the packs. There is a plug connector going to it.... You'll see it. The unit is actually two power transistors. One section of it supplies pulses to the primary of coil one [1&4 cyl] and the other part sends pulses to the 2&3 cyl coil. The unit is known to become intermittent... and you'll lose spark from one of the coil packs. Check it out. There is a testing procedure in the service manual.
Here are a few of my posts:
See: http://www.dsmtuners.com/forums/showthread.php?postid=388252#post388252
See: http://www.dsmtuners.com/forums/showthread.php?postid=313654#post313654
See: http://www.dsmtuners.com/forums/showthread.php?postid=198707#post198707
See: http://www.dsmtuners.com/forums/showthread.php?postid=192412#post192412
See: http://www.dsmtuners.com/forums/showthread.php?postid=126338#post126338
There are more posts but enough is enough!!!!! My fingers are tired!!
GOOD LUCK >>> Write back with results.

 

[Gesex]

97 gsx with 1g head swap. my power transistor is zip tied to the uicp
i didnt think to check the power transistor at first because i didnt think that if it went bad it would just cause 1 of the packs to not work. i figured if it was bad it would crap out both of them.

im gonna check that transistor tomorrow and try swapping out my friends transistor and see if it works. id hate to spend the $150 or so on a new transistor and then have that not be the problem. thanks for all the help though, i really appreciate it

 

[Gesex]

tested the power transistor today with the d-cell battery and all that stuff. sure enough, the test for cylinders 2 & 3 were dead. thanks for the advice laserblue.

 

[laserblue]

YOU'RE WELCOME!

Wow at last I got one right!!!!!... AND I got a 'thank you'!!! . . .Feels gooooooood!!

 

[Gesex]

dammit! turns out i tested it wrong. my power transistor is good, along with the other one i just bought. i hooked up both transistors and still no spark on 2&3 cylinders. anyone have any other ideas of what to check?

btw-i checked all 4 coil packs, and they are all good, so my problem lies somewhere else.

 

[teg21]

ecu?

also laserblue, if the power transistor goes out would that effect only one coil pack? Are there 2, one for each coilpack? Seems like all 4 cylinders would have to not get spark if this was the problem

 

[turbobird92]

go to a junk yard and get one got mine for 20 bucks

 

[Otis]

CAS??????

 

[Gesex]

Originally posted by teg21
ecu?

also laserblue, if the power transistor goes out would that effect only one coil pack? Are there 2, one for each coilpack? Seems like all 4 cylinders would have to not get spark if this was the problem

there is only one transistor. it runs both coil packs, but it can make just one of them fail.

im going to check the cam angle sensor and the crank angle sensor, since thats about all thats left. Of the 5 things i know of that control spark (coil pack(s), power transistor, cam angle sensor, crank angle sensor, and ecu), those are the only 2 things i havent checked out yet.

btw- pulled the ecu yesterday. no leaking caps woo-woo!

 

[laserblue]

teg21,
Go up to post 2 and read, please. The power transistor unit is actually two transistors. Each works one coil pack separately, so you can lose spark to only two cylinders.