Need help please....
Thread Starter
Joined: Jul 2003
Posts: 4,613
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From: Deer Park Tx
Need help please.... LS3 416 stroker.
Car runs fine at start up.
after it reaches its operating temp the motor starts to sputter, backfire, hesitate, and basically feel like it is not firing at all..
No codes are being thrown, no limp mode message..
let the car cool down and then start it back up and it runs fine until it gets to operating temp..
then its back to sputtering and backfiring...
any suggestions..
I took it to a friend of mine mechanics shop, and he couldn't find anything wrong. but he said there was something going on...
Car runs fine at start up.
after it reaches its operating temp the motor starts to sputter, backfire, hesitate, and basically feel like it is not firing at all..
No codes are being thrown, no limp mode message..
let the car cool down and then start it back up and it runs fine until it gets to operating temp..
then its back to sputtering and backfiring...
any suggestions..
I took it to a friend of mine mechanics shop, and he couldn't find anything wrong. but he said there was something going on...
It would but I have no idea how many cycles it would take. I've had one break on me and it acted very similar. Maybe log the coolant temp pid and see what's reported or just swap it out. They are pretty cheap
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Joined: Mar 2013
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From: Mooresville, NC
Not necessarily. Had a LSX swapped bel air in the shop yesterday with no IAT period and no codes.
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Verdad Gallardo Thread Starter
Joined: Jul 2003
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From: Deer Park Tx
i found a code last night B1S1 CODE low voltage?
so I bought an O2 last night and put it in and no dice..
still same problem..
the o2's stop moving around after it warms up.. stays bottomed out at around 50 and every so often it jumps up to 800 or so.. and them bottoms out again for a while.. i think this might explain why it felt like it was going in and out of limp mode.. but it appears the one o2 I replaced was not the problem..... that was $140 lost....
so I bought an O2 last night and put it in and no dice..
still same problem..
the o2's stop moving around after it warms up.. stays bottomed out at around 50 and every so often it jumps up to 800 or so.. and them bottoms out again for a while.. i think this might explain why it felt like it was going in and out of limp mode.. but it appears the one o2 I replaced was not the problem..... that was $140 lost....
Thread Starter
Joined: Jul 2003
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From: Deer Park Tx
I could give it a try.. has to be a hell of a lot cheaper than an O2 sensor
Thread Starter
Joined: Jul 2003
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From: Deer Park Tx
when I get home later today I am going to look at these things to see if maybe one of these could be it....
-The MAF (Mass Air Flow) Sensor is dirty or faulty
-Vacuum leak downstream of the MAF sensor
-Possible cracked vacuum or PCV line/connection Faulty or stuck open PCV valve
-Failed or faulty oxygen sensor (bank 1, sensor 1)
-Sticking/plugged or failed fuel injector
-Low fuel pressure
-Exhaust leak between engine and first oxygen sensor
-The MAF (Mass Air Flow) Sensor is dirty or faulty
-Vacuum leak downstream of the MAF sensor
-Possible cracked vacuum or PCV line/connection Faulty or stuck open PCV valve
-Failed or faulty oxygen sensor (bank 1, sensor 1)
-Sticking/plugged or failed fuel injector
-Low fuel pressure
-Exhaust leak between engine and first oxygen sensor
Thread Starter
Joined: Jul 2003
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From: Deer Park Tx
well I change out the coolant temp sensor in the side of the block..
seemed to work at first.. took it alot longer to start to stutter, and back fire..
but this time instead of the AFR going to 12:5 and staying there it went WAY lean????
any ideas???
any help???
seemed to work at first.. took it alot longer to start to stutter, and back fire..
but this time instead of the AFR going to 12:5 and staying there it went WAY lean????
any ideas???
any help???
Thread Starter
Joined: Jul 2003
Posts: 4,613
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From: Deer Park Tx
took maf out and cleaned it..
still doesnt run right?
Tune runs way lean when at normal operating temp.
should I replace the maf any ways?
I am blind here... stumbling in the dark...
any ideas?
still doesnt run right?
Tune runs way lean when at normal operating temp.
should I replace the maf any ways?
I am blind here... stumbling in the dark...
any ideas?
Thread Starter
Joined: Jul 2003
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From: Deer Park Tx
if the car runs well for 5-10 minutes. would it still be the pump? I would figure it to be the pump if it did this from start up.
Sounds like the wiring to B1S1 is the problem - judging from the code and the O2 sensor action you are describing... check and make sure you haven't burnt a wire somewhere...
Thread Starter
Joined: Jul 2003
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From: Deer Park Tx
I am leaning more and more to the O2's.
replaced maf no difference.
check fuel pressure at fuel rail, and it is at 58 PSI constant.
replaced coolant temp sensor. (didnt change the car going into limp mode, but it did cause the A/F to go from rich when it was stumbling to dead lean when stumbling.)
I have run out of daylight today but will check the wiring tomorrow afternoon..
thanks for the suggestion..
If wiring is not the problem I am up that creek with out a paddle....