Popping and misfire when under boost

[Mike70gtx]

The car will drive good and run smooth until you hit it hard. Somewhere over 1/2 throttle. I thought it was the ignition module again so I got one from a board member that was only supposed to have 5 passes on it. The coil checked out good and swapped the module and it is just as bad or worse. When this first started the car would start off great at wide open and then it would get sluggish after a few seconds into wide open. Now it has been misfiring. New plugs and the wire are nearly new. Any suggestions as I begin complete diagnosis.

 

[BenPutnam]

I have the same problem:

I just got my car back from getting a transmission overhaul which probably has nothing to do with this problem but now at WOT it misses, cracks and pops at high (5k+) RPM. It seems to run fine unless I'm out on the interstate and really lay into it.

Any ideas?

My Scan Master says the 02 sensor is reading around 789 so I don't think it's a lean condition.

 

[jpratt]

Double then triple check the plug wires. Crossed or loose wires play havoc.

 

[Quick6'n'-K.C.]

I would have to point to coil pack and ignition module, wires or plugs.

Usually the more load you put weak parts under, they tend to rear their ugly heads under wide open throttle.

Whats the gap in your plugs?

Have you checked the resistance in your spark plug wires? Even if they are new and one is arching against a piece of metal, then you will get a under load miss.

Check the wires for burn marks, pull the plugs and see what they look like..

I had over 35K on my last set of NGK UR5 spark plugs and wires, the car started bucking and popping and farting and backfiring soo bad, it started blowing 7/32 hoses off the map sensor and the inline check valves...

I replaced the plugs and made a set of new wires, NO MORE PROBLEMS, been problem free for 2 months

BW

 

[meanchicken]

Coilpack.
At least that's what it was on my GN last year.

 

[Mike70gtx]

New ur5's gapped at 32. Put on a "supposed to be good" ignition module and put a a good spare coil that checked out at 11.5 ohms across the board. I'll swap out the wires again. That was a problem before. I am about ready to buy the thing from caspers to check out modules and coils. I do have a Caspers cam sensor cap with the red light. I've heard some guys have problems with them. I read where you can get the car running and unhook it. If so, is it supposed to run alright with it unhooked?

 

[Quick6'n'-K.C.]

I have one of those caspers coil pack and ignition module testers and its paid for itself over and over again.

Just last week i tested 5-6 modules and over 15 coil packs, ended up having 3 bad coil packs that i had no idea they were bad....

If you own a few turbo buicks, its a must have tool.

The only down side of it, is the tester WILL NOT test the ALUMINUM FINISHED wells aftermarket ignition modules that are commonly used as replacements for our cars... It wont make it spark up the coils during testing, so if you have them, it wont do you any good.

If you have the original ones, it will test them fine.

Personally, ive thought of going to the type II 3800 series II ignition setup, 30.00 at the junk yard and there are 100's of them at the junk yard.

BW

 

[FreeBoost]

Check crank sensor for correct clearance on crank sensor. If sign of contact with interuptor replace sensor.

 

[83ttypecooled]

Hi,
I have been through this before. The symptoms seem to point to an ignition failure,but guess what guys, fuel pressure can be a big issue.Our cars need a steady supply of gas at the correct pressure, or poop! Hook a gauge with a long hose to your test port,tape it to the windshield, and take a run.Pressure should raise linearly with boost. If it doesn't, change the pump.
I fought this problem for a while, and changed all the ignition components, my fuel pump was the cause, all along.It never hurts to check; that's what medical doctors do. Good luck with your problem!

 

[bmackinnon]

Put on a "supposed to be good" ignition module and put a a good spare coil that checked out at 11.5 ohms across the board.

Agree with both 'chicken and 'KC. Symptoms perfectly describe a bad/weakening coil pack. The resistance test DOES NOT definitively confirm a good coil.... ask me how I know... Yup... casper's tester needed here... I am seriously considering the Series II ign. as well.....

 

[Quick6'n'-K.C.]

Agree with both 'chicken and 'KC. Symptoms perfectly describe a bad/weakening coil pack. The resistance test DOES NOT definitively confirm a good coil.... ask me how I know... Yup... casper's tester needed here... I am seriously considering the Series II ign. as well.....

The only thing i found on gnttype was what years to get them from, i am not sure if there is a aftermarket plug and play harness to go from the stock LC2 harness to plug into the SERIES 2 ignition module..

I prefer not to cut the wires under the hood of my car, in the future i would like to be able to switch between the two just incase something happened at the track and i didnt have spares.

BW

 

[jpratt]

The only thing i found on gnttype was what years to get them from, i am not sure if there is a aftermarket plug and play harness to go from the stock LC2 harness to plug into the SERIES 2 ignition module..

I prefer not to cut the wires under the hood of my car, in the future i would like to be able to switch between the two just incase something happened at the track and i didnt have spares.

BW

Sounds like a pigtail harness needs to be made by Mr Spina.

 

[TurboBuRick]

Check crank sensor for correct clearance on crank sensor. If sign of contact with interuptor replace sensor.

X2

 

[WINDMILL]

coil pack

i have the series 2 coil pack on my car. it just plug straight in no spliceing. these are the single coil packs?

 

[Mike70gtx]

Explain the series 2. I would have ordered the caspers tester today but I didn't get time to. By the time I get their set up to test coil and wires I will have spent close to $175. I'm pretty sure the coil I put on was good since I swapped it out when I got my new ignition module and coil 3000 miles ago. So I put the spare on the shelf. There is a chance the $75 GM module I bought from from someone on here that only had 5 passes on it was no good. By the time I get the tester and then if I have to buy a new module (over $200). That could be a lot of money I could use to convert to something else. What are the options? Series 2 and is the other one a distributer. And how major is it to do that swap and are there any advantages or disadvantages?

 

[Mike70gtx]

Explain the series 2. I would have ordered the caspers tester today but I didn't get time to. By the time I get their set up to test coil and wires I will have spent close to $175. I'm pretty sure the coil I put on was good since I swapped it out when I got my new ignition module and coil 3000 miles ago. So I put the spare on the shelf. There is a chance the $75 GM module I bought from from someone on here that only had 5 passes on it was no good. By the time I get the tester and then if I have to buy a new module (over $200). That could be a lot of money I could use to convert to something else. What are the options? Series 2 and is the other one a distributer. And how major is it to do that swap and are there any advantages or disadvantages?

 

[Quick6'n'-K.C.]

Explain the series 2. I would have ordered the caspers tester today but I didn't get time to. By the time I get their set up to test coil and wires I will have spent close to $175. I'm pretty sure the coil I put on was good since I swapped it out when I got my new ignition module and coil 3000 miles ago. So I put the spare on the shelf. There is a chance the $75 GM module I bought from from someone on here that only had 5 passes on it was no good. By the time I get the tester and then if I have to buy a new module (over $200). That could be a lot of money I could use to convert to something else. What are the options? Series 2 and is the other one a distributer. And how major is it to do that swap and are there any advantages or disadvantages?

Since i already have alot of coils and modules on hand, send your parts to and from and i will check them for free. My zip code is 66212 if you want to check shipping charges online.

WINDMILL- Are you saying you have 3 individual coils that the spark plug ends are all on one side of the top coil pack? Thats is what i was referring to as the series 2 mid 90s coil and module setup

 

[WINDMILL]

coil

yes, thats it. you can see it in the pic

 

[Quick6'n'-K.C.]

I see you dont have a air filter, but i cant really see the coil pack.

No wires were cut? Ive never put the series II on my car or any car, really had no problems with maf sensors or modules. Plugs right in and runs? Maybe i missed a few years... wouldnt suprise me one bit if i was wrong.

BW

 

[WINDMILL]

coil

i bought all the stuff from the parts store except module. it bolts straight up. the reason i have no air filter is i was putting on a trans plus and lt1 maft.