Misfire??
Thread Starter
Intermediate
Joined: Oct 2001
Posts: 29
Likes: 0
From: Bixby OK
Misfire??
I am new to posting, but I have been a forum member since I bought my 99 MN6 coupe over two years ago. The car was completely stock until last month when I opted for a Procharger P-1SC. I still even have the stock exhaust. The car was tuned by Ed Wright and I want to share the before and after results and get some opinions. Stock SAE RWHP was 299.6 and stock torque was 311.1. After the S/C installation, the RWHP jumped to 440 at 5500 rpm and the torque was 434.5. Above 5500 the engine had some misfiring but then smoothed out and topped out at 477.5 HP at 6400 rpm with 7 pounds of boost. I can duplicate the misfiring on the street and Ed’s people think it is ignition related (stock metal shields arcing). It feels like it does when the rev limiter kicks in. I have ordered some MSD wires, but after reading on the forum I am wondering if I might have fuel delivery problems. Has anybody experienced a similar situation after installing a supercharger? Sorry for the long post!
Supporting Vendor
Joined: Jul 2003
Posts: 6,486
Likes: 2
From: http://www.mphparts.com 800-364-1975
Re: Misfire?? (motorokie)
I am new to posting, but I have been a forum member since I bought my 99 MN6 coupe over two years ago. The car was completely stock until last month when I opted for a Procharger P-1SC. I still even have the stock exhaust. The car was tuned by Ed Wright and I want to share the before and after results and get some opinions. Stock SAE RWHP was 299.6 and stock torque was 311.1. After the S/C installation, the RWHP jumped to 440 at 5500 rpm and the torque was 434.5. Above 5500 the engine had some misfiring but then smoothed out and topped out at 477.5 HP at 6400 rpm with 7 pounds of boost. I can duplicate the misfiring on the street and Ed’s people think it is ignition related (stock metal shields arcing). It feels like it does when the rev limiter kicks in. I have ordered some MSD wires, but after reading on the forum I am wondering if I might have fuel delivery problems. Has anybody experienced a similar situation after installing a supercharger? Sorry for the long post!
Pro
Joined: Dec 2002
Posts: 667
Likes: 0
From: her AK
Re: Misfire?? (motorokie)
Without driving the car it's hard to say...but after my Mag/heads/cam/long tube etc install at Cartek I drove for about two weeks and it was solid...then I noticed hesitation/misfire....turned out to be a bad plug wire....replaced the plug wires and a month later same thing happened...finally nailed it down to high temps melting the plug wires....bought a new set of wires and the koolsox insulators and have been AOK ever since.
:cheers:
:cheers:
Le Mans Master
Joined: Jun 2003
Posts: 5,409
Likes: 0
From: Kentucky basketball is life the rest is just details
Re: Misfire?? (99C5ragtop)
Good numbers. :thumbs: Go with plugs and wires first. I don't know if you still have stock plugs in, but I had the same kind of problem with the high rpms due to the increased air coming in blowing out the spark. It sounded exactly like the rev limiter. I replaced the stock plugs with NGK TR6 plugs gapped at .35 and the problem went away. I'd bet you're having the same problem. :cheers:
Thread Starter
Intermediate
Joined: Oct 2001
Posts: 29
Likes: 0
From: Bixby OK
Re: Misfire?? (jpas)
Will do! I got my new MSD plug wires yesterday. I think I will install those before I change the plugs (they are only 2 week old Autolite copper) and see if the wires fix it. I want to know what the problem actually was (is).
Le Mans Master
Joined: Jun 2003
Posts: 5,409
Likes: 0
From: Kentucky basketball is life the rest is just details
Re: Misfire?? (motorokie)
Will do! I got my new MSD plug wires yesterday. I think I will install those before I change the plugs (they are only 2 week old Autolite copper) and see if the wires fix it. I want to know what the problem actually was (is).
