Engine sputters during WOT?
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Engine sputters during WOT?
Any ideas what it could be? Its a 2002 automatic highly modified with supercharger.
On take off at Wide open throttle after 3500 rpms its sputters or shakes a bit. Am I running only on 7 cylinders? Would this typically happen. I did get a P0200 code a week ago but had a faulty fuel injector. Need thoughts Thanks
On take off at Wide open throttle after 3500 rpms its sputters or shakes a bit. Am I running only on 7 cylinders? Would this typically happen. I did get a P0200 code a week ago but had a faulty fuel injector. Need thoughts Thanks
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
STEALERSHIP!?! That would be the very LAST place I would take a highly modified car to! 
If it were MY car,,, The very first thing that I would check and or change are the sparkplug wires and sparkplugs.
The last time that I helped someone who lived in France with the EXACT SAME ISSUE,, the very first thing I asked him was: " What are the conditions of the plugs and wires?" He stated they are NEW!
After a week + of having him check EVERY POSSIBLE THING THAT COULD CAUSE MULTIPLE RANDOM MISFIRES, he offered to fly me to France to fix his car!!
Before I accepted that EXPENSIVE outcome, I asked him to remove a plug and send me a picture of the condition of the plug. I wanted to see if I could see fire ring on the insulator.
The plug was the wrong one for a FI Set Up and they were ALL FOULED black!
New correct Sparkplugs solved his issue. Damn, I was so much wanting to visit France!!
SO,,,, When was the last time you looked at the SPARKPLUGS and WIRES??
Bill
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
STEALERSHIP!?! That would be the very LAST place I would take a highly modified car to! If it were MY car,,, The very first thing that I would check and or change are the sparkplug wires and sparkplugs.
The last time that I helped someone who lived in France with the EXACT SAME ISSUE,, the very first thing I asked him was: " What are the conditions of the plugs and wires?" He stated they are NEW!
After a week + of having him check EVERY POSSIBLE THING THAT COULD CAUSE MULTIPLE RANDOM MISFIRES, he offered to fly me to France to fix his car!!
Before I accepted that EXPENSIVE outcome, I asked him to remove a plug and send me a picture of the condition of the plug. I wanted to see if I could see fire ring on the insulator.
The plug was the wrong one for a FI Set Up and they were ALL FOULED black!
New correct Sparkplugs solved his issue. Damn, I was so much wanting to visit France!!
SO,,,, When was the last time you looked at the SPARKPLUGS and WIRES??
Bill
Unless I should not run a tech 2 on the car please let me know. Not getting other codes other than that P0200 which I believe was a faulty fuel injector. Haven't got it since a couple of weeks ago.
Wondering would a hairline fracture on the plug cause this as well?
Last edited by corvet786c; Jun 24, 2015 at 11:05 AM.
Le Mans Master
Joined: Feb 2004
Posts: 8,629
Likes: 16
From: York PA
Thanks Bill, They are NGK TR 6 plugs. I recently changed them and look at them about a month ago. And they looked brownish at the time. I am using MSD 8.5 conductor plug wires, They are also new about 2 weeks ago. The gap on the plugs are .35
Unless I should not run a tech 2 on the car please let me know. Not getting other codes other than that P0200 which I believe was a faulty fuel injector. Haven't got it since a couple of weeks ago.
Wondering would a hairline fracture on the plug cause this as well?
Unless I should not run a tech 2 on the car please let me know. Not getting other codes other than that P0200 which I believe was a faulty fuel injector. Haven't got it since a couple of weeks ago.
Wondering would a hairline fracture on the plug cause this as well?
Faulty injector could blow your motor
Replace the plugs & try not to crack them (again)
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Thanks Bill, They are NGK TR 6 plugs. I recently changed them and look at them about a month ago. And they looked brownish at the time. I am using MSD 8.5 conductor plug wires, They are also new about 2 weeks ago. The gap on the plugs are .35
Unless I should not run a tech 2 on the car please let me know. Not getting other codes other than that P0200 which I believe was a faulty fuel injector. Haven't got it since a couple of weeks ago.
Wondering would a hairline fracture on the plug cause this as well?
Unless I should not run a tech 2 on the car please let me know. Not getting other codes other than that P0200 which I believe was a faulty fuel injector. Haven't got it since a couple of weeks ago.
Wondering would a hairline fracture on the plug cause this as well?
A cracked plug is NOT going to cause you a P-200 DTC.
Recommend that you find the FUSES and REALY that provide POWER to the Injectors and COILS and make sure that they are:
1. Not loose, corroded in the fuse box slot.
2. Check the ACTUAL voltage being supplied to and from the fuse by reading the TEST POINTS on top of the fuse to chassis ground If it not full battery voltage, you are going to have issues.
3. Check the coil and injector wiring harness that runs down the drivers and passengers side of the engine between the heads and intake manifold. Make sure that its not damaged and has exposed wires. Especially in the area where it bends around or use to bend around the black metal bracket behind the drivers side fuel rail.
Fuses and relays:
Coils:
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Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
Might check with Gene at Cutrag and get some GM Red Performance wires, plugs and heat sox while your at it...
http://www.cultragfactoryparts.com/
http://www.cultragfactoryparts.com/
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Might check with Gene at Cutrag and get some GM Red Performance wires, plugs and heat sox while your at it...
http://www.cultragfactoryparts.com/
http://www.cultragfactoryparts.com/
If the wire, and boot insulation is good and they still SNAP properly on the coil and plug and you can OHM out the wires end to end and see very low resistance (I think MSD advertises like 20 ohms resistance) on every wire,, the wires are good for now.
I still prefer and use GM Performance RED wires!
Racer
Joined: Jan 2012
Posts: 398
Likes: 22
From: Las Vegas NV
Good advice so far. Never a bad idea to check your grounds. I had some high rpm sputtering issues not too long ago...ground to the back of drivers side cylinder head had worked itself loose. Wasnt getting any codes.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If you look at the injector schematic, you will see that G-106 is that ground and YEP,,, that ALSO can cause a P0200 DTC
Heres what it looks like attached to the head (head is removed for mods
)
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,136
Likes: 139
From: Port St Lucie Florida
Thanks for all the help and replies, *Problem fixed*
Under boost and massive fuel from the custom tune, it was blowing out the spark. I had to close the gap some on the spark plugs. From .35 to .22-.25, Idle is much better and does not sputter as bad. from a 50 mph roll.
Under boost and massive fuel from the custom tune, it was blowing out the spark. I had to close the gap some on the spark plugs. From .35 to .22-.25, Idle is much better and does not sputter as bad. from a 50 mph roll.