What plugs ? Im popping....

[HOTSIX]

Car is an '85 GN hotair.....

I have an awful popping / missing problem - hence my other post.....in Hot Air forum.

I currently have AC Delco R44TS plugs gapped at .035" installed.

Are these correct ????

See below :

Car sputters and pops heavily under load but not in idle. Cant drive her like this.....

I have:

-new AC Delco plugs, R44TS gapped at .035"
-new GM O2 sensor
-new 87 GN coil and IGN module
-new 8.8MM plug wires
-stock chip and ECM
-FP set to 32-35 PSI at idle (lvac line off)
-using 93 octane gas
Jeremy (NOCOOLER) sold me an 85 ECM with a Pitbull chip in it. Should I try that ECM/chip or try new plugs ? Could my stock chip be toast ?

 

[84tt]

I have a similar set-up
I use Autolite 24 sparkplugs gapped to about 31 or so works ok
but I have never really track tested(doesn't sputter)
How are your maf sensor readings?

 

[John Larkin]

It could be the plugs. It could also be that low fuel pressure. Your pump should be adequate but give the car some more fuel. How do the insulators on the plugs look? Bone white? If so then, it's very lean. Crank it up to 40 line off and see if that adjustment only helps. Does the car ever get into boost when this sputtering happens?

A Pitbull chip has alot of timing in it. You'd need 94 octane minimum with not a whole lot of boost to run ok. I've ridden in a car with a Pitbull chip and it pulled hard for a stock car but he was running 100 unleaded too.

 

[blackbuick87]

Just got done fixing the exact same problem on my 87, would idle fine but pop under ANY kind of load. Thought it might be the MAF but the SM showed the MAF was quite active.

Ended up changing the coil pack and plug wires, appears to be running fine now.

 

[FreeJack]

BlackBuick87...


When you went WOT did you hear numerous popping sounds like static discharge? That's what I am experiencing. I don't think its KNOCK but I could be wrong. What type of plug wires did you go with?

 

[HOTSIX]

Thanks guys

Hey John - I have the stock chip in it now - just bought the R43TS plugs today...not in yet tho. No boost during this sputtering...

I will pump up the gas to 40 PSI line off and let you know. Gettin' frustrated.

Checked 2 plugs last night and they looked quite normal.

Got some negative thoughts about my plug wires....Crane Cams 8MM cheap wires (on sale awhile ago). Maybe a good place to look since Blackbuick87 has same problem and changed his wires and coil.

I got a new coil and module - but cheap wires. I'm leaning towards changing the wires.

But ill up the PSI on the gas first - let ya know.

 

[Intercooler]

Where is the Scan-Tool?


It helps to have a little data!

 

[blackbuick87]

I purchased a set of 8.5 mm Magnecore wires from Ramchargers. My plugs were looking fine when I pulled them also, not fouled at all. Mine would run OK when the engine was not hot, but after about three miles would start missing and backfiring. Try testing your coilpack when its HOT, whether off the motor or heat it in the oven a little.

 

[HOTSIX]

Sorry - no scan tool yet...
Gotta do the 87 ECM conversion first...

Just changed all the plugs to R43TS plugs gapped at .035

#4 was fouled - black sooty coating on it. Checked compression on #4 - 130 PSI and it held for at least 5 mins...till I unscrewed the tester.

All the other plugs were ok and compression same on other cyls.

All the other plugs looked normal.

Why is #4 fouled ? The coilpack connection was fine. Bad plug ? Bad wire ?

 

[FlyinGN]

as crazy as it sounds try gapping the plugs a little tighter.. Like a .033 .. Its a no cost change and see if it helps.. I have seen that in the past..