Turbo Buick Forums banner


654 Views 7 Replies 5 Participants Last post by  JRGN
hey, just purchased a 87T had the codes 13 and 34 fixed both, changed out plugs had bosch plat plugs that were fouled and blue in color, found that the coil pac was on backwards turned around, has a adj fuel reg and the pressure was 80 on stock inj lowered to 38, also replaced the kenny bell chip with a GM stock chip, car is showing no codes but when the car is not under a load it idles fine but once it is under a load it a acts like it has a miss and runs like crap, car is not throwing any codes and everything is in spec. was just woundering if it could be the module, I plan on doing a compression test and a leak down test any help would be appreciated. thanks Jr.
1 - 8 of 8 Posts
I would start by checking the resistance between each pair of coil terminals (front terminal to rear terminal). Normally the resistance is in the range of 11k-13K ohms. Check it when the engine is hot. If the resistance is outside of this range, the coil is probably bad and you need a new coil pack. Note that this test is about 75% reliable and sometimes the coil will pass the test and still be bad.

And, yes, the module could be bad as well. Without a Casper's coil/module tester, the best way to trouble shoot the thing is by swapping with someone else's coil/module pack.

You are confident the plug wires are good?

Could easily be your Module or your coil pak. If your coil pak ohms out right, it still could be bad.....
Good luck!
Oh by the way use AC Delco plugs....cheap and they work!


Best time so far: 12.78 at 107.5mph on radials, 2.05 60 ft
Car weight without driver 3610 lbs
See less See more
Do you know if anyone's been in the engine latly, cause it's real easy to set the cam sensor 180' out. With it in backwards the car will do all kinds of weird things, but that doesn't really sound like your problem.

As Steve said check the coils. The coil being backwards will not affect how the engine runs, I changed mine in '96 and and it crapped out again this summer so when I changed it I found that I had put in on backwards.
As for the module they tend to not cause this type of problem, I'm not saying it can't be your problem but with ign modules they tend to be a work or don't work situation.

Good luck
See less See more
hey guys thanks for the input I have another coil pac and put that on and see what it does, i'll let you'all know what happens. Jr.
well, I checked the coil pac that the previous owner had and it ohmed bad, checked the one one the car and it looked good, everything at 11.2, but I am going to borrow one from a friend that he knows is good, should find out tomorrow and will let everyone know.
See less See more
Here's what I do.
Use an inductive timing light just above the boots of the wires to check for firing.Run the rpm's up a bit and check again.Do this for each wire.
If two misfires are paired,check the coilpcak powers.
Now,the towers up top can Ohm out all right,but there can still be a problem on the primary side of the coilpacks.
I bought a used coilpack and module from the wreckers and here's what I found:
Primary side resistance on these packs is about 1000 Ohms.I compared it to a month old unit I bought at Cotton's,they were the same.
Secondary is about 11,400 new,13,000+ used.
While you've got the coilpack off the module,you can check between the primary and secondary sides for resistance.Should be infinite on all packs.
If the coilpack checks good on all these tests and you've got a pair of cylinders misfiring[same pair on coilpack],then you've more than likely got a bad module.
Hope that helps a bit.

Give em' hell!

[This message has been edited by The Radius Kid (edited November 24, 2001).]
See less See more
Hey, guys I believe I have found my problem, changed the coil pac and module to a known good one but that was not the grimlin
went ahead and did a comp check and didn't know if I was doing it rite because cyl #1 had 10 lbs and #3 had 0, but the rest were anywere from 140-145, so I am hoping a blown headgasket.Only thing is that I don't know how bad the the det. was to blow a head gasket and how bad he may have hammered the bearings all I can say is that time will tell. Thanks Jr.
See less See more
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.