Misfire!
crb806
03-10-2006, 07:07 PM
My 1995Z28 has started misfire after it gets warmed up, for example on the interstate it will start stumbing at low rpms, jumping up then back down, then it just gets worse and worse and worse, and it is throwing no codes, i just got plugs changed and i am not ready to get an opti because it could be something else causing it, really aggrevating me!
malletslinger
03-11-2006, 04:17 PM
Check wires, coil, and make shure the dizzy isnt loose.
crb806
03-11-2006, 05:36 PM
drove the car to turn a movie in and was fine on the way there but down the right the road from my house all of sudden missed once then two more times, awww crap, just coasted down the road into my driveway. could bad 02 sensors be causing this, i read somewherre that the ones up front will switch into a different mode when the car reaches a certain temp and if they are bad could it cause this problem? anyone ever hear of this... just trying to eleminate things it could be...
ChipMaker
03-12-2006, 01:01 PM
This sounds a lot like something that has been happening to me. I think I've solved it and resolved the last of the codes from coming up. I have a 93 LT1 Formula that has had a misfire for a long time. Some other symptoms were, lights flicker at night (dimming) with no apparent reason. Exhaust backfire from time to time. (indicator too that your cat-conv is dead). Very difficult to idle at different temps. Sometimes when cold, sometimes when hot. Etc.
I spoke to a friend yesterday who has been helping me on this and I just got a code 53 which is a Voltage Regulator gone haywire. He said that it's not uncommon for them to fail slowly and spike volteage at times. This appears to be what is going on with my car. I'll have the alternator tomorrow. Story goes tho that when this happened 10 days ago, it blew my ignition module, loaded the exhaust with fuel (new in dec) and blew it up. I have a new exhaust as of friday, resolved some other issues and now I'm faced with this same trouble. I have been getting no codes. I drove the car last night and it made it three miles and back with the volt gauge a little high. I was just waiting for it to go nuts but the two times it's had this problem have been after the 25 mile point so I doubt that everything was warmed up enough last night to cause it again.
I suspect that the voltage regulator weakened my ignition module and killed that. I did have an air pump issue but that's now resolved. That was a code 26. The 53 code has only ever come up once. According to the info I've seen, you have to go over 17 volts to get that (or under 10). Either could be true I guess. With the battery so well charged, I doubt it's undervoltage. Who knows.
If the ignition module is on the way out, you'll probably pick up that stumbling frequently at a particular temp or time. Look out when it goes, they go in a hurry. At $90 tho, it's not an item you just go replace for fun.
I spoke to a friend yesterday who has been helping me on this and I just got a code 53 which is a Voltage Regulator gone haywire. He said that it's not uncommon for them to fail slowly and spike volteage at times. This appears to be what is going on with my car. I'll have the alternator tomorrow. Story goes tho that when this happened 10 days ago, it blew my ignition module, loaded the exhaust with fuel (new in dec) and blew it up. I have a new exhaust as of friday, resolved some other issues and now I'm faced with this same trouble. I have been getting no codes. I drove the car last night and it made it three miles and back with the volt gauge a little high. I was just waiting for it to go nuts but the two times it's had this problem have been after the 25 mile point so I doubt that everything was warmed up enough last night to cause it again.
I suspect that the voltage regulator weakened my ignition module and killed that. I did have an air pump issue but that's now resolved. That was a code 26. The 53 code has only ever come up once. According to the info I've seen, you have to go over 17 volts to get that (or under 10). Either could be true I guess. With the battery so well charged, I doubt it's undervoltage. Who knows.
If the ignition module is on the way out, you'll probably pick up that stumbling frequently at a particular temp or time. Look out when it goes, they go in a hurry. At $90 tho, it's not an item you just go replace for fun.
ChipMaker
03-12-2006, 01:12 PM
Oh, and since I see you're looking into a new distributor, I'll say this. I just got one for $159 that was a remanf. Good as new, was not my problem. It was going to be tho with the bearing in it that was shot. probably had but a few days left to live anyhow.
My point was, years back there was no aftermarket or reman stuff to buy. When I called the dealership for mine it was $670. From the parts store it was $159 with exchange. Much better. (core was more than the dist tho).
If you're getting no codes, I highly doubt that you have an issue with the distributor and in 95, they had fixe the water issue that caused mine to go bad.
Last note. IF you decide to get one. Be sure to have an E3(i think) in a screwdriver form BEFORE you start. I bought a socket to get the dist cap off and that was ok for 2 of the screws but the other two I had to put the socket in a external grinder to get it in to the screw heads. Thats a long hole you have to reach in and a 1/4" socket won't fit. Just fyi. The screws are like an inside out torx. All the rest is easy stuff. But your misfire is most likely coming from elsewhere.
One other question, does it ever just completely cut out and come right back on? If so, Just go the the module and change it out. It's right on the coil assembly and real easy to change.
My point was, years back there was no aftermarket or reman stuff to buy. When I called the dealership for mine it was $670. From the parts store it was $159 with exchange. Much better. (core was more than the dist tho).
If you're getting no codes, I highly doubt that you have an issue with the distributor and in 95, they had fixe the water issue that caused mine to go bad.
Last note. IF you decide to get one. Be sure to have an E3(i think) in a screwdriver form BEFORE you start. I bought a socket to get the dist cap off and that was ok for 2 of the screws but the other two I had to put the socket in a external grinder to get it in to the screw heads. Thats a long hole you have to reach in and a 1/4" socket won't fit. Just fyi. The screws are like an inside out torx. All the rest is easy stuff. But your misfire is most likely coming from elsewhere.
One other question, does it ever just completely cut out and come right back on? If so, Just go the the module and change it out. It's right on the coil assembly and real easy to change.
crb806
03-12-2006, 03:23 PM
I am not lookign at buying an opti because alot of people have had this problem an opti was not the cause, i want to try the inexpensive things first. It doesnt cut out. after it has been warmed up for a while it miss fire once, then again then and get worse and worse, doesnt seem to missfire as bad in acceleration as when i am tring to keep a steady speed with low rpms. Its wierd because it will be warmed up good and still be running fine then all of a sudden, here we go MISFIRE:crying:
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