Mechanics

MISFIRING RANDOMLY

1996 Chevrolet Corsica

Hey, I was hoping someone could help me with my problem. I have a 1996 Corsica 2.2L with 120,000 miles. At first we believed this to be water in the gas/bad gas because there was a little in the gas from the filter when it was replaced. Or it was dirty fuel injectors. But here's the problem.

The problem will happen from various degrees of severity. But, the car will usually misfire on one cylinder when I start it after it has been sitting for a while. Then when I accelerate, the problem will clear out. As I drive the car may misfire very briefly every few miles and I will lose some power for a split second. Occassionally the cylinder will misfire for several seconds, these periods are more rare while driving but usually occur while I'm going up, just stopped or went around a sharp curve. I have no idea where to begin with this.

I've never taken a car into a shop for anything other than very quick repairs where I get it back the next day. If I had to take it in on Thursday if I can't figure this out, how much longer might it take to get the car back. It would hurt a lot to be without the car longer than Thursday to Monday.
Avatar
Willv28
October 15, 2007.



You should let the shop know you need the car by Monday

When was it its last tune up
Do you add coolant
Good luck

BMRFIXIT
Oct 16, 2007.
It sounds like one of two possible problems! Have the fuel pressure checked and make sure it can hold the pressure, or it maybe a sign of a bad crank sensor or bad conector to the sensor!

Well, a proper tune up was a while ago. I always change oil, oil filter, check and add fluids, coolant has been full for a while and hasn't had any added in a while. Recently I changed air filter, fuel filter, plugs and wires. This was after the problem started.

I'll take it to them Thursday afternoon. I do want to replace the fuel pump relay first. Is. One of them was not There's a group of 4 relays under the hood on the passenger's side near the firewall. One of them I know is the fuel pump relay, I just don't know which one it is. One of them was not attached to the holder and was sitting on the frame and was free to bounce around. I put it back and things seemed to run a little better. I just don't know which one that was I put back and when it came off. I might have some faulty wiring or relay to that. But I can hear the pump turn on for the two seconds when I put in start before I crank the engine. So, I doubt it.

I'm by no means a car expert, I can do things if someone explains it to me and instructs me. Figuring out what IS causing a problem is a different story. Heh

Know of a way I can test the relay to see if it's working?

Tiny
Willv28
Oct 17, 2007.
How can I check to see if that's the case with the crank sensor?

Tiny
Willv28
Oct 17, 2007.
Well, a proper tune up was a while ago. I always change oil, oil filter, check and add fluids, coolant has been full for a while and hasn't had any added in a while. Recently I changed air filter, fuel filter, plugs and wires. This was after the problem started.

I'll take it to them Thursday afternoon. I do want to replace the fuel pump relay first. Is. One of them was not There's a group of 4 relays under the hood on the passenger's side near the firewall. One of them I know is the fuel pump relay, I just don't know which one it is. One of them was not attached to the holder and was sitting on the frame and was free to bounce around. I put it back and things seemed to run a little better. I just don't know which one that was I put back and when it came off. I might have some faulty wiring or relay to that. But I can hear the pump turn on for the two seconds when I put in start before I crank the engine. So, I doubt it.

I'm by no means a car expert, I can do things if someone explains it to me and instructs me. Figuring out what IS causing a problem is a different story. Heh

Know of a way I can test the relay to see if it's working?[/Quote: 7e9b5011c0]
check the coil s
And if it’s a crank sensor will cause stalling or no start
But everything is possible you can check that
As for the relay if the fuel pump relay stops working the car will no start
Until oil pressure built up
And if you can scan the car for codes that will help pin point the trouble area
Good luck

BMRFIXIT
Oct 17, 2007.
I took it to the only place I know has a code scanner, the nearest Advance. Like last time when I went to an Auto Zone, the only thing that the print out said was misfire on cylinder 1. Only the previous time I swear they said cylinder 3. But they had people who did not want to be there working and I couldn't hear I word they said and they didn't print it out. I know they can get more than just that with the good scanners they have and actually read some data. I'm nervous of sounding stupid so I don't ask.

I have a sneaky suspicion that it may the the pressure regulator. That's what I'm going to check. I check the vacuum tube and reset it and it seemed to run better longer. The screen could be clogged up. It could have corroded from the water that was likely in the tank. If not, I guess I'll take it in.

Tiny
Willv28
Oct 17, 2007.
I took it to the only place I know has a code scanner, the nearest Advance. Like last time when I went to an Auto Zone, the only thing that the print out said was misfire on cylinder 1. Only the previous time I swear they said cylinder 3. But they had people who did not want to be there working and I couldn't hear I word they said and they didn't print it out. I know they can get more than just that with the good scanners they have and actually read some data. I'm nervous of sounding stupid so I don't ask.

I have a sneaky suspicion that it may the the pressure regulator. That's what I'm going to check. I check the vacuum tube and reset it and it seemed to run better longer. The screen could be clogged up. It could have corroded from the water that was likely in the tank. If not, I guess I'll take it in.[/Quote: 01b6bb8bdc]

If you have a misfire on cylinder # 1
You should start by checking that cylinder
And the cause of the misfire is it
Spark or fuel or compression or vacuum leak
Check if you have spark on that cyl
Check plug and wire and coil
Check injector check for vacuum leak that may affect this cylinder
Check compression.
Good luck

BMRFIXIT
Oct 18, 2007.