car hits 4600rpm and POW, backfire and shuts off???
#42
LS1Tech Co-Founder
iTrader: (34)
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Answer these questions:
-It backfires out the (a) intake or (b) exhaust?
-Afterwards it stays running Y or N?
-It breaks up going through the rpms, Y or N?
-If I manually hold a gear, like leave it in 2nd, and just accelerate the car slowly, it still does this Y or N, and it does it at ____rpm?
Possible culprits:
-Bad reluctor wheel, side or end play
-Harness is bad
-Power to crank sensor is grounding out somewhere
-Thrust bearing is wortn, and the crank has too much endplay as a result
-Bad crank
Mine was a loose reluctor wheel back in 2002.
-It backfires out the (a) intake or (b) exhaust?
-Afterwards it stays running Y or N?
-It breaks up going through the rpms, Y or N?
-If I manually hold a gear, like leave it in 2nd, and just accelerate the car slowly, it still does this Y or N, and it does it at ____rpm?
Possible culprits:
-Bad reluctor wheel, side or end play
-Harness is bad
-Power to crank sensor is grounding out somewhere
-Thrust bearing is wortn, and the crank has too much endplay as a result
-Bad crank
Mine was a loose reluctor wheel back in 2002.
#43
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Answer these questions:
-It backfires out the (a) intake or (b) exhaust?
-Afterwards it stays running Y or N?
-It breaks up going through the rpms, Y or N?
-If I manually hold a gear, like leave it in 2nd, and just accelerate the car slowly, it still does this Y or N, and it does it at ____rpm?
Possible culprits:
-Bad reluctor wheel, side or end play
-Harness is bad
-Power to crank sensor is grounding out somewhere
-Thrust bearing is wortn, and the crank has too much endplay as a result
-Bad crank
Mine was a loose reluctor wheel back in 2002.
-It backfires out the (a) intake or (b) exhaust?
-Afterwards it stays running Y or N?
-It breaks up going through the rpms, Y or N?
-If I manually hold a gear, like leave it in 2nd, and just accelerate the car slowly, it still does this Y or N, and it does it at ____rpm?
Possible culprits:
-Bad reluctor wheel, side or end play
-Harness is bad
-Power to crank sensor is grounding out somewhere
-Thrust bearing is wortn, and the crank has too much endplay as a result
-Bad crank
Mine was a loose reluctor wheel back in 2002.
With my PCM, the car shuts down totally. With my buddys PCM the car would just cut out completly but would stay running.
The car is smooth going through the RPMs, right before is shuts down, I might get one miss.
It does this in any gear usually about 5000 rpms.
Reluctor wheel was tight when I tried moving it with my finger.
Crankshaft had NO play when I tried using a crow bar to pry it forward.
fuel pressure stays at 58psi the entire time
#45
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Not yet. The guy that tuned my car is being a *** and basically told me he's too busy working on his house and doesnt give a **** about his company (PCMFORLESS) right now...yes those are his exact words. ![MAD](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_mad.gif)
![Punch](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_punch.gif)
It looks like I might take it to a dealership and have it done.
Question: In order for a new crank sensor to work, do you need to do a relearn?? anybody??
my buddy installed a new crank sensor and never did a relearn, he has no problems at all.
![MAD](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_mad.gif)
![Punch](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_punch.gif)
It looks like I might take it to a dealership and have it done.
Question: In order for a new crank sensor to work, do you need to do a relearn?? anybody??
my buddy installed a new crank sensor and never did a relearn, he has no problems at all.
#46
Banned
iTrader: (10)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Not yet. The guy that tuned my car is being a *** and basically told me he's too busy working on his house and doesnt give a **** about his company (PCMFORLESS) right now...yes those are his exact words. ![MAD](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_mad.gif)
![Punch](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_punch.gif)
It looks like I might take it to a dealership and have it done.
Question: In order for a new crank sensor to work, do you need to do a relearn?? anybody??
my buddy installed a new crank sensor and never did a relearn, he has no problems at all.
![MAD](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_mad.gif)
![Punch](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_punch.gif)
It looks like I might take it to a dealership and have it done.
Question: In order for a new crank sensor to work, do you need to do a relearn?? anybody??
my buddy installed a new crank sensor and never did a relearn, he has no problems at all.
#50
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Not yet. The guy that tuned my car is being a *** and basically told me he's too busy working on his house and doesnt give a **** about his company (PCMFORLESS) right now...yes those are his exact words. ![MAD](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_mad.gif)
![Punch](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_punch.gif)
It looks like I might take it to a dealership and have it done.
Question: In order for a new crank sensor to work, do you need to do a relearn?? anybody??
my buddy installed a new crank sensor and never did a relearn, he has no problems at all.
![MAD](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_mad.gif)
![Punch](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_punch.gif)
It looks like I might take it to a dealership and have it done.
Question: In order for a new crank sensor to work, do you need to do a relearn?? anybody??
my buddy installed a new crank sensor and never did a relearn, he has no problems at all.
#52
11 Second Club
iTrader: (4)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Backfires out the exhaust
With my PCM, the car shuts down totally. With my buddys PCM the car would just cut out completly but would stay running.
The car is smooth going through the RPMs, right before is shuts down, I might get one miss.
It does this in any gear usually about 5000 rpms.
Reluctor wheel was tight when I tried moving it with my finger.
Crankshaft had NO play when I tried using a crow bar to pry it forward.
fuel pressure stays at 58psi the entire time
With my PCM, the car shuts down totally. With my buddys PCM the car would just cut out completly but would stay running.
The car is smooth going through the RPMs, right before is shuts down, I might get one miss.
It does this in any gear usually about 5000 rpms.
Reluctor wheel was tight when I tried moving it with my finger.
Crankshaft had NO play when I tried using a crow bar to pry it forward.
fuel pressure stays at 58psi the entire time
Those are the exact symptoms my friend is having also. His factory harness should be fine but his bottom end was rebuilt and the mechanic may have put it in wrong or damaged a wire.
#53
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Jesus Christ, you call me on a SUNDAY when I am hanging a ceiling fan in my children's bedrooms that were built 2 months behind schedule due to weather and contractor delays so they can move into warm bedrooms instead of sleeping out in our camper during the construction/renovation and you want me to kiss your butt? I told you to come on up on Saturday and I would be around all day to help you with your car, instead you decide to call me on Sunday???? Hell, I've been overly nice trying to help you diagnose this car that had multiple melted wire issues, then the messed up fuel injector install that could have killed us all with the leaking fuel, plus if I remember correctly a few plug wire issues. This sure is the thanks I get for trying to help. Guess it is time for someone else to help you if you don't like the fact that I chose my FAMILY over your car on a Sunday
Dude, theres so much bullshit in what you wrote. Stay out of my thread. We'll take this to the PMs.
Last edited by 30th t/a; 10-30-2007 at 09:59 PM.
#55
Registered User
Join Date: Oct 2007
Location: K-State University
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Hey this is the "buddy" with the same problem. I dont even have 2000 miles on my 2000 camaro's re-built motor, and one day it all happened. Every thing you have decribed about the drivability is idendical to my situation.
I was wondering if your car threw a code for the crank shaft sensor right when it happened? Mine did, and I got a new sensor, and it ran great for about an 30 min. then it shot the ***** again! After that I did a crank relearn and that did nothing.
My buddy dataloged it with EfI live and it showed I had split O2 sensors, thats about as far as I've gotten.
So dont feel like your the only one who is putting up with this bull ****.
I was wondering if your car threw a code for the crank shaft sensor right when it happened? Mine did, and I got a new sensor, and it ran great for about an 30 min. then it shot the ***** again! After that I did a crank relearn and that did nothing.
My buddy dataloged it with EfI live and it showed I had split O2 sensors, thats about as far as I've gotten.
So dont feel like your the only one who is putting up with this bull ****.
Last edited by CompCamaro; 10-30-2007 at 09:21 PM.
#56
FormerVendor
iTrader: (45)
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Well, this has not been mentioned but... find a friend who's f-body runs right and swap his MAF onto your car. Easing into the upper RPMs, the car is not in PE and fuel trimming is keeping mixture inline, then, as you go into PE, at 4K RPMs and above, all fueling comes from the MAF unless it fails diagnostic tests (then you run off the VE). Heck, for grins, just try unplugging your OWN MAF and drive (so that the car fails into speed density; referencing tables rather than MAF signal for fueling calcs). See what happens, maybe the MAF is failing in a way that does not trigger a DTC.
#57
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hey this is the "buddy" with the same problem. I dont even have 2000 miles on my 2000 camaro's re-built motor, and one day it all happened. Every thing you have decribed about the drivability is idendical to my situation.
I was wondering if your car threw a code for the crank shaft sensor right when it happened? Mine did, and I got a new sensor, and it ran great for about an 30 min. then it shot the ***** again! After that I did a crank relearn and that did nothing.
My buddy dataloged it with EfI live and it showed I had split O2 sensors, thats about as far as I've gotten.
So dont feel like your the only one who is putting up with this bull ****.
I was wondering if your car threw a code for the crank shaft sensor right when it happened? Mine did, and I got a new sensor, and it ran great for about an 30 min. then it shot the ***** again! After that I did a crank relearn and that did nothing.
My buddy dataloged it with EfI live and it showed I had split O2 sensors, thats about as far as I've gotten.
So dont feel like your the only one who is putting up with this bull ****.
#58
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Well, this has not been mentioned but... find a friend who's f-body runs right and swap his MAF onto your car. Easing into the upper RPMs, the car is not in PE and fuel trimming is keeping mixture inline, then, as you go into PE, at 4K RPMs and above, all fueling comes from the MAF unless it fails diagnostic tests (then you run off the VE). Heck, for grins, just try unplugging your OWN MAF and drive (so that the car fails into speed density; referencing tables rather than MAF signal for fueling calcs). See what happens, maybe the MAF is failing in a way that does not trigger a DTC.
#59
TECH Fanatic
iTrader: (17)
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Just to clarify... did you replace the wires for the crank sensor? Im talking 100%. From the PCM all the way out to the senor, and including a NEW plug?
Sounds like you "let the smoke out" when you hit the wire to positive by accident. That could cause issues along the entire circuit.
It sounds like you might have to wipe the slate clean. Try to grab a good harness, and a fresh PCM. See if the car runs with that. Then get a re-tune.
Or have a tuner check out the tune like you've been trying to do. Its a weird problem...and its weird that it just popped up. But these PCMs do weird things sometimes. Ive learned that. Like mine having VATs disabled...but then all of a sudden it working...then again all of a sudden being disabled. Wacky crap.
Keep us updated!
J.
P.S... The MAF sensor is a good suggestion too.
Sounds like you "let the smoke out" when you hit the wire to positive by accident. That could cause issues along the entire circuit.
It sounds like you might have to wipe the slate clean. Try to grab a good harness, and a fresh PCM. See if the car runs with that. Then get a re-tune.
Or have a tuner check out the tune like you've been trying to do. Its a weird problem...and its weird that it just popped up. But these PCMs do weird things sometimes. Ive learned that. Like mine having VATs disabled...but then all of a sudden it working...then again all of a sudden being disabled. Wacky crap.
Keep us updated!
J.
P.S... The MAF sensor is a good suggestion too.
#60
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Just to clarify... did you replace the wires for the crank sensor? Im talking 100%. From the PCM all the way out to the senor, and including a NEW plug?
Sounds like you "let the smoke out" when you hit the wire to positive by accident. That could cause issues along the entire circuit.
It sounds like you might have to wipe the slate clean. Try to grab a good harness, and a fresh PCM. See if the car runs with that. Then get a re-tune.
Or have a tuner check out the tune like you've been trying to do. Its a weird problem...and its weird that it just popped up. But these PCMs do weird things sometimes. Ive learned that. Like mine having VATs disabled...but then all of a sudden it working...then again all of a sudden being disabled. Wacky crap.
Keep us updated!
J.
P.S... The MAF sensor is a good suggestion too.
Sounds like you "let the smoke out" when you hit the wire to positive by accident. That could cause issues along the entire circuit.
It sounds like you might have to wipe the slate clean. Try to grab a good harness, and a fresh PCM. See if the car runs with that. Then get a re-tune.
Or have a tuner check out the tune like you've been trying to do. Its a weird problem...and its weird that it just popped up. But these PCMs do weird things sometimes. Ive learned that. Like mine having VATs disabled...but then all of a sudden it working...then again all of a sudden being disabled. Wacky crap.
Keep us updated!
J.
P.S... The MAF sensor is a good suggestion too.
yep, I replaced the entire length of the crank sensor wires. All three of them. I didnt replace the Pigtail connector part though that snaps into the sensor itself.
I did install my buddys working PCM but the car still would "cut out" and fall on its face at the same RPMs that it would shut off with my PCM. However, the funny thing is, the car would not shut completly off. it would stay running. Also with his PCM, the car would not backfire either.
Even though I replaced the crank sensor wires, my harness has been through alot so Im planning on replacing it.