So I have'nt had the car back very long. Runs flawless under normal driving conditions. As boost builds, say around 12 PSI up it starts spitting/misfiring. Boost is currently set at 16 PSI. Alcohol is off, zero knock from the gauge. On rare occasion it may clear up and pull like a freight train, but then back to misfiring. NGK plugs look clean and brand new. Installed a new Delco coil just to rule that out. Magnacore {R 100/10mm} wires look new but unsure of age. Again, car idles well, runs flawless around town. Has a Scanmaster but I'm looking for the manual to learn how to read it. Any clues where to start. Should I start with a cheap set of wires to rule that out?
Spitting and misfiring under heavy boost.
- Thread starter robertf
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TexasT
Texas, Where are you from
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scan master?
What are the readings for the maf? Does it go to 255 at wot?
What are the readings for the maf? Does it go to 255 at wot?
scgnx2
Active Member
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That is also a typical symptom of a bad coil pack/ignition module. I think most of us long time turbo Buick owners have been through this more than once...
I'll make a run in a bit and check.
Replaced the coil but don't have a spare module at the moment. Won't have the TR6 setup till latter next month so I may wait before purchasing a module.
Common items that cause this :
1) coil pack/ ignition module
2) bad maf
3) plug wires / plug gap
4) Fuel pump
plug wires plug gap is a easy check .. fuel pump can be verified with a fuel pressure gauge off the rail ( Easy check) .
bad maf usually can be picked up on the scanmaster but not always ... IMHO if its a stock MAF .. that needs to go right in the trash can .. LS1 Maf upgrade
that leaves the module .. I always have a known good one to rule that out .. bet its 1 of those 4
626gn
Well-Known Member
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Ignition module could be suspect. Attached is some reading material for your scanmaster.
http://www.vortexbuicks-etc.com/Scantool_Readings.htm
http://www.vortexbuicks-etc.com/Scantool_Readings.htm
scgnx2
Active Member
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Good move, I'm going TR6 next time I need a new ignition module or coil pack.
Just ran down the steert.
Just made a quick run. She reads 255. I did notice though it pulled really hard on a couple of runs until the temp came up a bit. Seems heat is involved so hoping for a bad module.
SCOOBY DOO
BASED CANADIAN PATRIOT!!
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On your WOT run...when you hit recall...what did it say?
It has the LS1 upgrade. Everything else has checked out. plugs/fuel psi are fine. I'm going to shoot for the module. When I purchased the car back, it came with a huge box of parts. Im sure I saw a module in the box but will contact my friend to see if it's junk.
SCOOBY DOO
BASED CANADIAN PATRIOT!!
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What are your BLM's at idle with the engine warmed up? What did your Scanmaster say when you hit recall after your WOT run?
Did'nt hit recall. Just read 255 at WOT on MAF. I will go try another run shortly.
does the fuel pressure rise 1to1?what is the afr whens the sputtering happens?does it knock?
