misfire / stumble at low rpm

[sweetride]

I'm getting a misfire while driving at low rpm (<2k) if the engine comes under load climbing a grade or light acceleration . WOT seems fine and no CE codes are displaying . A search of these forums indicates the problem might be plug wires . It's possible the plugs/wires are original (67k miles).

 

[PioneerCrazed]

Sounds exactly like mine when my plug wires went bad. At about 1800 RPMs I think it was the worst when under load. Is your car a first gen(93-96) or a 2nd gen(97-98)? If you have a 2nd gen, you will have coil packs and I've heard there short "plug wires" going bad also.

 

[jerryjfunk]

Yeah, I got a stumbles/misfires at low RPM without throwing a check engine code when my coil boot cracked on my '98. It's most likely wires ('93-'96) or the coil boots ('97-'98).

 

[JC1994]

Sounds exactly like mine when my plug wires went bad. At about 1800 RPMs I think it was the worst when under load. Is your car a first gen(93-96) or a 2nd gen(97-98)? If you have a 2nd gen, you will have coil packs and I've heard there short "plug wires" going bad also.

:I

 

[sweetride]

Thanks for the replies . It's a gen1 96 LSC with the 290 hp engine option . Would you recommend oem wires and should i change the plugs while i'm at it ? I let the car go off-lease at 50k kilometers and got it back at 97k km . I don't have the service record for that 47k km gap .

 

[PioneerCrazed]

If you're doing wires, I'd definitley do plugs while you are at it; cheap insurance. The plugs most use are autolite 754's gapped .054. Wires, you can pretty much use any you like. I used NAPA's brand, they seemed to be pretty nice. A lot on here use MSD wires because they're pretty cheap for what you're getting.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=MSD-32219&N=115&autoview=sku

Quoted from BlackIceLSC:

do 1 cylinder at a time, gap your plugs to .054, and by all means, buy a magnetic spark plug socket...makes it much easier...especially if your tower seals have dripped a bit of oil onto the old plugs.

anti-sieze the threads, smear some dielectric grease on the wire boots, and install the new plug.

it takes longer to remove the beauty cover and intake tube, than it does to swap plugs.

Gen 1-15 minutes
Gen 2-10 minutes.

these are accurate numbers...but it isnt a race. take your time, and do them carefully.

FWIW, the Mark VIII DOHC engine is easier to install plugs in than a pushrod V8...especially a big block Mopar engine in a A body!(one of the few cars that it WOULD be easier to change plugs with a lift!)

 

[Frogman]

Thanks for the replies . It's a gen1 96 LSC with the 290 hp engine option . Would you recommend oem wires and should i change the plugs while i'm at it ? I let the car go off-lease at 50k kilometers and got it back at 97k km . I don't have the service record for that 47k km gap .

Man, you shoulda gone for the 350HP engine option on that LSC... :lol:

ALL LSC's had the 290HP engine.

 

[sweetride]

Pioneercrazed : thanks for the info .

Frogman : thats more info than the local dealers could tell me . If i keep the car very long this time , it'll have a lot more than 350 hp .