FuzzyFish
Member
Where to start, anyways a few weeks ago I had my brother take my 89' in to do some work that I could not as had access to a lift. Later I get a call from him that it died on him. So I go out, and it's running but sounds as if it is dropping a cylender or two. So slowly we get the car home, and it keeps getting worse and worse until it loses all power and I have to shove it the rest of the way home.
I get it home and turn the key. And hear the fuel pump whine like it is out of gas. So I add some gas it fires up. However it is still running on what sounds like 4 or 5 cylenders. So just to be safe I follow it in my truck. We get to the station and fill it up. And go to leave. As soon as we leave I notice it is back-firing quite severely. Basically a solid blue flame (NOTE: There is no exhaust system beyond the y-pipe at this point) almost, and assuming this is around 3000rpms. And it starts losing cylenders as we get closer to home until it stops firing and needs a shove. (1/8th mile each way) I notice it's glowing underneath I take a look and the almost the entire y-pipe is glowing orange!
So two days later I finally get a chance to look at it. I get in fire it up, and sounds like it is running on 4 or 5 cylenders. And pull it in, first thing I try to do is pull codes, but I can not get any codes from it. However it does run through the self-test (fans on-off, various relays, fuel pump.)
Next I test for spark, and find that the center cyl. on the front bank was not firing at first. And everything almost appeared to be fine asides from that. After a few minutes it starts to backfire and sputter more. So I test the coil pack for any shorts. After testing it appears fine when cold. After a bit more testing I notice the following.
-All of the spark plugs on the rear bank are firing as they should.
-The rightmost plug (Assuming you are facing the smae direction as the car) seems to fire too often, with occasional missing.
-The center plug does not fire.
-The left plug fires for a bit very erratically for awhile and then stops after running for a bit.
After trying to swap plugs/wires there was not a noticable effect.
Accoring to my brother, the only things he did was try to help a friend (Who just so happens to have the same problem on his 93mtx for the past month) and swaped modules (Having no effect). And that it started to die on the highway so he got off and it died, and started a bit later.
However it was not the module, as I happen to have a spare one which I tried just in-case. I always thought the coil pack fired two plugs at once, whice only furthered my confusion as to why it is doing this.
The engine is definatly getting fuel, as it can easily be found on the offending plugs. I tested the wires to the coil pack and those were good. I even went so far as changing the cam sensor as it seem to fix the problem for many people that have had misfiring/hard start issues.
So my question is what else could be causing it to misfire on just one, or two cylenders.
Also is there anything normally near the y-pipe that could be damaged by the 700+ degree temperatures that could be caused by the pipe overheating(glowing).
I'm quickly running into a dead-end here, and tomarrow I'm about to tear into the wiring to fix a few other issues so that I can see stored codes.
Also to note this engine is due for it's 60k
Anyone ideas would be greatly appreciated, thanks.
-FuzzyFish
<small>[ December 30, 2003, 01:16 AM: Message edited by: FuzzyFish ]</small>
I get it home and turn the key. And hear the fuel pump whine like it is out of gas. So I add some gas it fires up. However it is still running on what sounds like 4 or 5 cylenders. So just to be safe I follow it in my truck. We get to the station and fill it up. And go to leave. As soon as we leave I notice it is back-firing quite severely. Basically a solid blue flame (NOTE: There is no exhaust system beyond the y-pipe at this point) almost, and assuming this is around 3000rpms. And it starts losing cylenders as we get closer to home until it stops firing and needs a shove. (1/8th mile each way) I notice it's glowing underneath I take a look and the almost the entire y-pipe is glowing orange!
So two days later I finally get a chance to look at it. I get in fire it up, and sounds like it is running on 4 or 5 cylenders. And pull it in, first thing I try to do is pull codes, but I can not get any codes from it. However it does run through the self-test (fans on-off, various relays, fuel pump.)
Next I test for spark, and find that the center cyl. on the front bank was not firing at first. And everything almost appeared to be fine asides from that. After a few minutes it starts to backfire and sputter more. So I test the coil pack for any shorts. After testing it appears fine when cold. After a bit more testing I notice the following.
-All of the spark plugs on the rear bank are firing as they should.
-The rightmost plug (Assuming you are facing the smae direction as the car) seems to fire too often, with occasional missing.
-The center plug does not fire.
-The left plug fires for a bit very erratically for awhile and then stops after running for a bit.
After trying to swap plugs/wires there was not a noticable effect.
Accoring to my brother, the only things he did was try to help a friend (Who just so happens to have the same problem on his 93mtx for the past month) and swaped modules (Having no effect). And that it started to die on the highway so he got off and it died, and started a bit later.
However it was not the module, as I happen to have a spare one which I tried just in-case. I always thought the coil pack fired two plugs at once, whice only furthered my confusion as to why it is doing this.
The engine is definatly getting fuel, as it can easily be found on the offending plugs. I tested the wires to the coil pack and those were good. I even went so far as changing the cam sensor as it seem to fix the problem for many people that have had misfiring/hard start issues.
So my question is what else could be causing it to misfire on just one, or two cylenders.
Also is there anything normally near the y-pipe that could be damaged by the 700+ degree temperatures that could be caused by the pipe overheating(glowing).
I'm quickly running into a dead-end here, and tomarrow I'm about to tear into the wiring to fix a few other issues so that I can see stored codes.
Also to note this engine is due for it's 60k
Anyone ideas would be greatly appreciated, thanks.
-FuzzyFish
<small>[ December 30, 2003, 01:16 AM: Message edited by: FuzzyFish ]</small>
