Every now and then my car starts to buck and stutter. Mostly when going from a stop, in second or first gear. I start going, and then it revs and drops, and bucks, almost like i'm tapping the gas. Other than that, the car is fine and drives fine, with no strange noises or anything like that. Anyone had this problem before? I have some ideas on what it could be, but i want to see what everyone else thinks. Thanks.

Yup i had it happen to me a bunch of times. Try changing your sparkplugs and check your wires. 9 times out of 10 its the sparkplugs. Oh yah stay away from v-power sparkplugs because they cause stuttering also.

im having that problem...AGAIN. the first time i changed the plugs (which were almost electrode-less) and it fixed it. but im pretty sure the wires are going bad. it looks like the spark is jumping from the top of the plug to the base where it site flush with the head. sucks.

Check the usual plugs and wires. IF thats not the problem, then check to make sure that one of the wiring harnesses is not getting burned by the EGR pipe and shorting out, Thats what mine is doing right now. Hope this helps.

I had that problem for a year, and replaced things until it died on the road eventually. It turned out being the ECU. If that's what it turns out for you, I've got my old one and I'll send it to you if you want to have it rebuilt. Can't hurt to try. Otherwise look for ignition problems. I know it sounds retarded, but I drove around the neighborhood with my timing light strapped to my hood to watch the ignition. You know there's something wrong when one wire sparks 4 times as fast as the other three :thumbsdown

along with the plugs and wires also check the ignition coil. I had a problem sorta like that and i replaced the coil, plugs and wires and it fixed it right up.

the plugs and wires arent that old. i know it's not the wires, but i'll check the plugs. i could be having some problems that messed one of them up or something. after that, I think I'll try a coil. How much are they? It's wierd because most of the time it drives normal, sometimes it will only buck or stutter once, and sometimes it seems like it's close to stalling. i have it some gas in third on the highway, and it would rev, and pull, and then stop for a second and no it again. it did it until I let off the gas. it sucks with this busy weekend, i dont know when i'll get a chance to look at it.

yea, i thought i had bought some bad/watery gas at first. but yes, its gotta be my wires. actually its just the #2 wire. the spark is arcng from the top to the base. sorry POS. off to the junkyard this weekend. if no luck, i'll be visiting Howellautomotive.com. =/

Just an added note, if you want to try replacing the coil pack, I want everyone to know that you can get a bolt on MSD coil pack that has the same plug and everything for us 420a's. Besides, it's cheaper than OEM, so why not have it. AND IT'S RED!!! :shrug Manicshift = Ricer:shrug

the msd coils are $65 at summitracing.com while the oem coils are like 100. The coil should help tho.

the coil pack isn't the same on all models, the earlier models have a diffent plug than the later models.

95 and some 96 models have the round part for the plug while the later ones have the flat plugs.

Yes, but if you talk to msd they can get you the right one. They sell two models, one for each plug. It's worth the call, because if you get the right plug, you'd have to be retarded to take longer than 3 minutes to swap them out.

howell offers a screamin demon coil that puts out 40k volts(?) compared to the stock 36k volts. im probably going this route and its only $64.95. Check my post in engine/performance.

wellit's not the coil. i'll have to check the plugs and wires. if it's neither one of those, then what?

the trick is to follow all of the wiring up back to the source. if it's not plugs->wires->coils it could be some wiring from some of the sensors thats fucked, might be a fucked sensor, or your ECU may be FUBAR

once i got home it was too dark to check my plugs. i changed the coil in the dark, and same with the wires, but no dice. still doing it. i'll have to check the plugs tomorrow afternoon. i wish I had some good lights in my garage.

well its not the plug, coil, or wires. this sucks. any more ideas?

If someone wants a set of plug wires, e-mail me. These are stock that I replaced with Magnecores. I kept them just in case, as a backup.

jholifield2003@comcast.net

Getting back to the issue, if your problem shows up at idle, check vacuum lines first. My car ran like shit at idle, tried to die, then ran fine above 1500 rpm. Turned out to be a bad EGR valve. If it's a timing problem, you will feel it throught the rpm range. In that case replace plugs, wires, and coil. Not familiar with ECU problems. I'll bet it's your EGR valve. Hope you get it running good.

btw, how many miles do you have?

somewhere around 98,000. it idles fine, and drives fine until i get on the gas. in neutral, it revs to redline just fine under full throttle. only under load does it stutter and jerk. No CELs (although I wish I did so I would know what the hell is wrong). I'm stuck now, I dont want to go replacing all kinds of shit that I dont need to. I already spend close to $100 on plugs and the coil pack, and neither did a damn thing.

well i finally got a CEL. did the key dance, and got the codes.

11- Loss of Cam angle sensor, or crank angle sensor.

31- EVAP solenoid circuit

42- No MFI relay output voltage at the PCM

not that that really helps me any. this is pissin me off.

as crazy as it sounds, a couple weeks ago i had the same problem and the problem was a fuse. it just so happened that my parking/gauge cluster lights went out and the jerking/hesitation started at the same time. when i replaced the fuse it fixed it. i have no idea how a fuse would affect something like that, but it sure as hell did.

hmmmmm. actually, the check engine light flashes with the stuttering. when it jerks forward, the light shuts off, but when it goes back to normal the light comes back on.

EDIT: just to clear that up, as the car bucks forward, the CEL shuts off, but when it drives normal for a split second, the light comes on, and the cycle repeats until I let off the gas.

well i would check the cam and crank angle sensors out, you got a cel for them so why not? If either are going bad you will get hesitation like that

yeah, make sure those sensors arent loose or something. ive heard of that situation happening after a few rebuilds when the cam or crank angle sensors werent tightened down properly. have you checked to make sure no wires are shorting out on your EGR tube? that happened to me. if not for the CEL, i may have guessed MAP sensor or O2 sensor as well. goodluck with it.

1999 Black C5
1997 Silver RS
Wiseco 8.8:1 Pistons(back to low compression!)
Eagle Rods
T3/T4 Turbo
Custom FMIC
Greddy Exhaust
390's
Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)

i checked both sensors, and the seemed fine. none of the EGR wires are shorting out. i think i'm going to go have it scanned at auto zone to get a better idea of whats wrong.

check your coolant temp sensor, not the sending unit, THE sensor if it is gunked up could cause this kind of problem, btw it wont throw a CEL to tell you it is messed up and scanners might not be able to detect it because it doesnt throw the CEL, but if you remove it and it looks bad replace it, it is only 8 bux, and i spent i dont know how much trying to fix this problem, i replaced-

FPR
fuel filter
plugs (three times)
coil pack
cam sensor (and all wires)
crank sensor (and all wires)
spark plug wires
ASD/Fuel pump relays
IAT sensor
tps sensor
ECU
..and just about the entire wiring harness

but did you get ANY cel's at all?

just a EGR CEL, and of course the CEL would blink when it wanted to die, or when it did die, but after it died and i did the "key dance" nothing showed up, for 8 bux just look into it it only takes 5 minutes to fix:thumbsup

i have this same problem, ive actually had it twice. the first time was caused by melted 02 sensor wires, got too close to the manifold. the 2nd time(currently) is because of a head gasket leak. do a compression check, if one cylinder is less than the others, thats probably it.(low compression can mean terrible things like fried rings/pistons as well, just pray beforehand)
crutan

my compression was 190 all the way across. I'll have to check the o2 sensor wire, but if that was the case, i would think it would throw a CEL related to the o2 sensor.