Need help/ suggestions with my lt4
11-15-2012, 06:25 AM
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Need help/ suggestions with my lt4 i have a 97 camaro with a an original lt1 block but has lt4 heads, throttle body, and injectors... the camaro is thorwing a few codes and i beleive they are all related to one issue. the codes are (P0420 catalyst system efficiency below threshold-Bank 1) (P0336 cranksfat position sensor A circuit range/performance) (P0335 Crankshaft position sensor A circuit) (P1371 ICM 4x reference too few pulses). the car fires RIGHT up and drives fine but i feel a lack of power. this camaro dynoed @400HP and i dont feel 400HP at all.i think this is all due to the crankshaft sensor mainly throwing everything else off. i also think the previous owner may have mishifted to an skipped a tooth an threw the timing off maybe as well. I DONT KNOW for sure. its possible its the opti, but im PRAYING it isnt. hoping its either the ignition coil maybe or crankshaft sensor. what do you guys think?
11-15-2012, 06:56 AM
#2
A few things going on here.
From what you described there's no way the car dyno'd at 400HP, especially if it only has LT4 heads. Either a.) you're failing to list several other mods or the more likely scenario b.) whoever told you it dyno'd 400HP was outright lying.
The codes you are seeing, specifically P0420, P0336 and P0335 are not crucial and won't cause any problems with how the PCM controls fueling and timing. The CPS is only there to detect misfires - the PCM doesn't even use it. The likely scenario here is that there's a wiring issue, the sensor is unplugged or broken or there is a problem with the CPS reluctor ring behind the timing cover (unlikely).
Skipping a tooth on the timing chain is very very unlikely - almost impossible.
The P1371 is more the problem as that points to the loss of low resolution pulse from the optispark. I would suspect the wiring harness that connects to the opti first. It's possible that the harness pins are corroded and create an intermittent connection.
I doubt it's the coil since the car starts fine and it certainly is not the CPS.
Conclusion: tell us more about the car. More specifics, what cam (if any), any tuning, etc.
Truthfully if the only symptom you're seeing is a few stored codes it's hard to believe your butt dyno since someone obviously inflated your expectations with that "400HP."
From what you described there's no way the car dyno'd at 400HP, especially if it only has LT4 heads. Either a.) you're failing to list several other mods or the more likely scenario b.) whoever told you it dyno'd 400HP was outright lying.
The codes you are seeing, specifically P0420, P0336 and P0335 are not crucial and won't cause any problems with how the PCM controls fueling and timing. The CPS is only there to detect misfires - the PCM doesn't even use it. The likely scenario here is that there's a wiring issue, the sensor is unplugged or broken or there is a problem with the CPS reluctor ring behind the timing cover (unlikely).
Skipping a tooth on the timing chain is very very unlikely - almost impossible.
The P1371 is more the problem as that points to the loss of low resolution pulse from the optispark. I would suspect the wiring harness that connects to the opti first. It's possible that the harness pins are corroded and create an intermittent connection.
I doubt it's the coil since the car starts fine and it certainly is not the CPS.
Conclusion: tell us more about the car. More specifics, what cam (if any), any tuning, etc.
Truthfully if the only symptom you're seeing is a few stored codes it's hard to believe your butt dyno since someone obviously inflated your expectations with that "400HP."
11-15-2012, 07:41 AM
#5
What cam?
What custom programming?
LT4 TB was the same as an LT1 TB.
You said.
so all further comments are based on RWHP as it would be measured with the car not just engine.
As said the LT4 full kit wont make anything approaching 400rwhp so right off the bat it sounds as if the guy you bought from was flatly dishonest, I would also suspect the car was put together wrong and that was the likely reason for the sale.
It gave you a CAT code but you didn't say it had longtubes and was catless, chances of making 400rwhp with stock manifolds is impossible NA or shorties through cats is still way outside the realm of possible unless you are forgetting to tell us about nitrous.
I am wondering about possibly Injectors not tuned for, which will ruin an engine, no reprograming atall or hypercrap, stock gears and or stall just a general bad setup assembled badly and a dishonest person claiming it made 400hp. Betting the car never ran right and that is why it was sold.
What custom programming?
LT4 TB was the same as an LT1 TB.
You said.
this camaro dynoed @400HP
As said the LT4 full kit wont make anything approaching 400rwhp so right off the bat it sounds as if the guy you bought from was flatly dishonest, I would also suspect the car was put together wrong and that was the likely reason for the sale.
It gave you a CAT code but you didn't say it had longtubes and was catless, chances of making 400rwhp with stock manifolds is impossible NA or shorties through cats is still way outside the realm of possible unless you are forgetting to tell us about nitrous.
I am wondering about possibly Injectors not tuned for, which will ruin an engine, no reprograming atall or hypercrap, stock gears and or stall just a general bad setup assembled badly and a dishonest person claiming it made 400hp. Betting the car never ran right and that is why it was sold.
11-15-2012, 07:58 AM
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A few things going on here.
From what you described there's no way the car dyno'd at 400HP, especially if it only has LT4 heads. Either a.) you're failing to list several other mods or the more likely scenario b.) whoever told you it dyno'd 400HP was outright lying.
The codes you are seeing, specifically P0420, P0336 and P0335 are not crucial and won't cause any problems with how the PCM controls fueling and timing. The CPS is only there to detect misfires - the PCM doesn't even use it. The likely scenario here is that there's a wiring issue, the sensor is unplugged or broken or there is a problem with the CPS reluctor ring behind the timing cover (unlikely).
Skipping a tooth on the timing chain is very very unlikely - almost impossible.
The P1371 is more the problem as that points to the loss of low resolution pulse from the optispark. I would suspect the wiring harness that connects to the opti first. It's possible that the harness pins are corroded and create an intermittent connection.
I doubt it's the coil since the car starts fine and it certainly is not the CPS.
Conclusion: tell us more about the car. More specifics, what cam (if any), any tuning, etc.
Truthfully if the only symptom you're seeing is a few stored codes it's hard to believe your butt dyno since someone obviously inflated your expectations with that "400HP."
From what you described there's no way the car dyno'd at 400HP, especially if it only has LT4 heads. Either a.) you're failing to list several other mods or the more likely scenario b.) whoever told you it dyno'd 400HP was outright lying.
The codes you are seeing, specifically P0420, P0336 and P0335 are not crucial and won't cause any problems with how the PCM controls fueling and timing. The CPS is only there to detect misfires - the PCM doesn't even use it. The likely scenario here is that there's a wiring issue, the sensor is unplugged or broken or there is a problem with the CPS reluctor ring behind the timing cover (unlikely).
Skipping a tooth on the timing chain is very very unlikely - almost impossible.
The P1371 is more the problem as that points to the loss of low resolution pulse from the optispark. I would suspect the wiring harness that connects to the opti first. It's possible that the harness pins are corroded and create an intermittent connection.
I doubt it's the coil since the car starts fine and it certainly is not the CPS.
Conclusion: tell us more about the car. More specifics, what cam (if any), any tuning, etc.
Truthfully if the only symptom you're seeing is a few stored codes it's hard to believe your butt dyno since someone obviously inflated your expectations with that "400HP."
yea that was my next thought abouut not REALLY bein 400, he did show me the dyno on the car and its also blue printed and remapped and i beleive he said it has a cam, ill have to ask specifically which one. sorry i dont know all the details onf the car.
11-15-2012, 08:02 AM
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11-15-2012, 08:07 AM
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What cam?
What custom programming?
LT4 TB was the same as an LT1 TB.
You said.
so all further comments are based on RWHP as it would be measured with the car not just engine.
As said the LT4 full kit wont make anything approaching 400rwhp so right off the bat it sounds as if the guy you bought from was flatly dishonest, I would also suspect the car was put together wrong and that was the likely reason for the sale.
It gave you a CAT code but you didn't say it had longtubes and was catless, chances of making 400rwhp with stock manifolds is impossible NA or shorties through cats is still way outside the realm of possible unless you are forgetting to tell us about nitrous.
I am wondering about possibly Injectors not tuned for, which will ruin an engine, no reprograming atall or hypercrap, stock gears and or stall just a general bad setup assembled badly and a dishonest person claiming it made 400hp. Betting the car never ran right and that is why it was sold.
What custom programming?
LT4 TB was the same as an LT1 TB.
You said.
so all further comments are based on RWHP as it would be measured with the car not just engine.
As said the LT4 full kit wont make anything approaching 400rwhp so right off the bat it sounds as if the guy you bought from was flatly dishonest, I would also suspect the car was put together wrong and that was the likely reason for the sale.
It gave you a CAT code but you didn't say it had longtubes and was catless, chances of making 400rwhp with stock manifolds is impossible NA or shorties through cats is still way outside the realm of possible unless you are forgetting to tell us about nitrous.
I am wondering about possibly Injectors not tuned for, which will ruin an engine, no reprograming atall or hypercrap, stock gears and or stall just a general bad setup assembled badly and a dishonest person claiming it made 400hp. Betting the car never ran right and that is why it was sold.
Last edited by Lt4Joe; 11-15-2012 at 08:18 AM.
11-15-2012, 09:00 AM
#9
You still didn't tell us what tranny it has.
I understand having to ask what cam.
the engine work and larger injectors both require reprogramming and I still haven't heard that said.
Larger injectors with stock programming can foul O2 sensors, and wash all the fuel from the cylinder walls removing protection from the rings which will then eat the cylinders and then the extra fuel will dilute the oil and start destroying bearings, it is even possible for too much fuel to cause detonation and destroy an engine like that.
3.73s are not a stock ratio, they might be appropriate if it has an A4 but are wrong if it is an M6.
If the guy had the A4 rebuilt as well as it seems everything else is done I give it a year.
If he had the shortblock gone through I would expect it to be screwed up too.
Auburn is NOT what I would go to for an aftermarket posi clutches to wear and not rebuildable.
If the gears and posi are that new does this confirm what I suspected that the car was sold almost as soon as the mods were done or sat awhile and was sold, never driven much with the mods?
a LOT of people completely **** up cars trying to "improve" things and what you are saying has all the hallmarks of exactly that sort of build.
Roughly where are you located, maybe someone competent can see the car and help you out.
You still haven't told us specifically what the car is even, we can guess 96-97 and you said Camaro.
Please make a list of everything you know about the car.
I understand having to ask what cam.
the engine work and larger injectors both require reprogramming and I still haven't heard that said.
Larger injectors with stock programming can foul O2 sensors, and wash all the fuel from the cylinder walls removing protection from the rings which will then eat the cylinders and then the extra fuel will dilute the oil and start destroying bearings, it is even possible for too much fuel to cause detonation and destroy an engine like that.
3.73s are not a stock ratio, they might be appropriate if it has an A4 but are wrong if it is an M6.
If the guy had the A4 rebuilt as well as it seems everything else is done I give it a year.
If he had the shortblock gone through I would expect it to be screwed up too.
Auburn is NOT what I would go to for an aftermarket posi clutches to wear and not rebuildable.
If the gears and posi are that new does this confirm what I suspected that the car was sold almost as soon as the mods were done or sat awhile and was sold, never driven much with the mods?
a LOT of people completely **** up cars trying to "improve" things and what you are saying has all the hallmarks of exactly that sort of build.
Roughly where are you located, maybe someone competent can see the car and help you out.
You still haven't told us specifically what the car is even, we can guess 96-97 and you said Camaro.
Please make a list of everything you know about the car.
11-15-2012, 04:34 PM
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You still didn't tell us what tranny it has.
I understand having to ask what cam.
the engine work and larger injectors both require reprogramming and I still haven't heard that said.
Larger injectors with stock programming can foul O2 sensors, and wash all the fuel from the cylinder walls removing protection from the rings which will then eat the cylinders and then the extra fuel will dilute the oil and start destroying bearings, it is even possible for too much fuel to cause detonation and destroy an engine like that.
3.73s are not a stock ratio, they might be appropriate if it has an A4 but are wrong if it is an M6.
If the guy had the A4 rebuilt as well as it seems everything else is done I give it a year.
If he had the shortblock gone through I would expect it to be screwed up too.
Auburn is NOT what I would go to for an aftermarket posi clutches to wear and not rebuildable.
If the gears and posi are that new does this confirm what I suspected that the car was sold almost as soon as the mods were done or sat awhile and was sold, never driven much with the mods?
a LOT of people completely **** up cars trying to "improve" things and what you are saying has all the hallmarks of exactly that sort of build.
Roughly where are you located, maybe someone competent can see the car and help you out.
You still haven't told us specifically what the car is even, we can guess 96-97 and you said Camaro.
Please make a list of everything you know about the car.
I understand having to ask what cam.
the engine work and larger injectors both require reprogramming and I still haven't heard that said.
Larger injectors with stock programming can foul O2 sensors, and wash all the fuel from the cylinder walls removing protection from the rings which will then eat the cylinders and then the extra fuel will dilute the oil and start destroying bearings, it is even possible for too much fuel to cause detonation and destroy an engine like that.
3.73s are not a stock ratio, they might be appropriate if it has an A4 but are wrong if it is an M6.
If the guy had the A4 rebuilt as well as it seems everything else is done I give it a year.
If he had the shortblock gone through I would expect it to be screwed up too.
Auburn is NOT what I would go to for an aftermarket posi clutches to wear and not rebuildable.
If the gears and posi are that new does this confirm what I suspected that the car was sold almost as soon as the mods were done or sat awhile and was sold, never driven much with the mods?
a LOT of people completely **** up cars trying to "improve" things and what you are saying has all the hallmarks of exactly that sort of build.
Roughly where are you located, maybe someone competent can see the car and help you out.
You still haven't told us specifically what the car is even, we can guess 96-97 and you said Camaro.
Please make a list of everything you know about the car.
I will call the previous owner today and get ALL the infor possible an contact you, I'm in California. Area code 94564. Anyone good out this way?
11-15-2012, 05:06 PM
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Yea I know EXACTLY what shopp your talking about, dude builds some pretty crazy ****, hes good for sure
11-16-2012, 12:23 AM
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You still didn't tell us what tranny it has.
I understand having to ask what cam.
the engine work and larger injectors both require reprogramming and I still haven't heard that said.
Larger injectors with stock programming can foul O2 sensors, and wash all the fuel from the cylinder walls removing protection from the rings which will then eat the cylinders and then the extra fuel will dilute the oil and start destroying bearings, it is even possible for too much fuel to cause detonation and destroy an engine like that.
3.73s are not a stock ratio, they might be appropriate if it has an A4 but are wrong if it is an M6.
If the guy had the A4 rebuilt as well as it seems everything else is done I give it a year.
If he had the shortblock gone through I would expect it to be screwed up too.
Auburn is NOT what I would go to for an aftermarket posi clutches to wear and not rebuildable.
If the gears and posi are that new does this confirm what I suspected that the car was sold almost as soon as the mods were done or sat awhile and was sold, never driven much with the mods?
a LOT of people completely **** up cars trying to "improve" things and what you are saying has all the hallmarks of exactly that sort of build.
Roughly where are you located, maybe someone competent can see the car and help you out.
You still haven't told us specifically what the car is even, we can guess 96-97 and you said Camaro.
Please make a list of everything you know about the car.
I understand having to ask what cam.
the engine work and larger injectors both require reprogramming and I still haven't heard that said.
Larger injectors with stock programming can foul O2 sensors, and wash all the fuel from the cylinder walls removing protection from the rings which will then eat the cylinders and then the extra fuel will dilute the oil and start destroying bearings, it is even possible for too much fuel to cause detonation and destroy an engine like that.
3.73s are not a stock ratio, they might be appropriate if it has an A4 but are wrong if it is an M6.
If the guy had the A4 rebuilt as well as it seems everything else is done I give it a year.
If he had the shortblock gone through I would expect it to be screwed up too.
Auburn is NOT what I would go to for an aftermarket posi clutches to wear and not rebuildable.
If the gears and posi are that new does this confirm what I suspected that the car was sold almost as soon as the mods were done or sat awhile and was sold, never driven much with the mods?
a LOT of people completely **** up cars trying to "improve" things and what you are saying has all the hallmarks of exactly that sort of build.
Roughly where are you located, maybe someone competent can see the car and help you out.
You still haven't told us specifically what the car is even, we can guess 96-97 and you said Camaro.
Please make a list of everything you know about the car.
its a 97 camaro. the tranny is just a ws6 rebuild, the motor is balanced and blue printed, bored 30over, it has an lt4 cam/lt4 kit, ported and polished cast heads, i called a shop that specializes in ls an lt and told him whats going on and he said the opti being faulty is causing alot of loss of power and that i may need to replace the water pump becuase i guess they leak on that sensor and can cause damage and that may be what of happened.
11-16-2012, 06:59 AM
#16
He means to ask if it is auto or manual trans. The lt4 topend kit from edelbrock claims 425 crank hp, or about 360rwhp. It souns like you have an auto trans. Did it ever run like you think it should or are you saying it doesnt feel like the amount of horsepower the seller claimed? If it is just a REAL lt4 top end they only had 330 CRANK hp from the factory, even if it is the edelbrock kit though, you do not have 400rwhp.
11-16-2012, 07:01 AM
#17
dohhhh...
ws6's came auto and man...is it an A4 or M6 and what did this guy do...rub his crystal ball and yell... OPTIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
Come on...no one can diagnose over the phone...most idiots just blame opti out of pure ignorance...not saying that it couldn't be..just saying
ws6's came auto and man...is it an A4 or M6 and what did this guy do...rub his crystal ball and yell... OPTIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
Come on...no one can diagnose over the phone...most idiots just blame opti out of pure ignorance...not saying that it couldn't be..just saying
11-16-2012, 07:03 AM
#18
Yeah my thoughts exactly. I don't know maybe a WS6 car was only available with one of the trannies?
YOU are in no way qualified to own this car and paying someone to sort it out is going to cost a LOT. You still can't answer the question as to what tranny is in it, not ******* complicated automatic or manual
Given the thought and care put into everything the "rebuilt" shortblock is likely a step backwards from stock.
If I saw a for sale description that said this.
I would RUN. The entirety of the way that is written just says NO knowledge whatsoever , you said he showed you a 400hp chart, that pretty much proves dishonesty on his part.
YOU are in no way qualified to own this car and paying someone to sort it out is going to cost a LOT. You still can't answer the question as to what tranny is in it, not ******* complicated automatic or manual
Given the thought and care put into everything the "rebuilt" shortblock is likely a step backwards from stock.
If I saw a for sale description that said this.
its a 97 camaro. the tranny is just a ws6 rebuild, the motor is balanced and blue printed, bored 30over, it has an lt4 cam/lt4 kit, ported and polished cast heads,
11-18-2012, 07:20 PM
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Yeah my thoughts exactly. I don't know maybe a WS6 car was only available with one of the trannies?
YOU are in no way qualified to own this car and paying someone to sort it out is going to cost a LOT. You still can't answer the question as to what tranny is in it, not ******* complicated automatic or manual
Given the thought and care put into everything the "rebuilt" shortblock is likely a step backwards from stock.
If I saw a for sale description that said this.
I would RUN. The entirety of the way that is written just says NO knowledge whatsoever , you said he showed you a 400hp chart, that pretty much proves dishonesty on his part.
YOU are in no way qualified to own this car and paying someone to sort it out is going to cost a LOT. You still can't answer the question as to what tranny is in it, not ******* complicated automatic or manual
Given the thought and care put into everything the "rebuilt" shortblock is likely a step backwards from stock.
If I saw a for sale description that said this.
I would RUN. The entirety of the way that is written just says NO knowledge whatsoever , you said he showed you a 400hp chart, that pretty much proves dishonesty on his part.
Last edited by Lt4Joe; 11-18-2012 at 08:08 PM.
11-18-2012, 07:25 PM
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He means to ask if it is auto or manual trans. The lt4 topend kit from edelbrock claims 425 crank hp, or about 360rwhp. It souns like you have an auto trans. Did it ever run like you think it should or are you saying it doesnt feel like the amount of horsepower the seller claimed? If it is just a REAL lt4 top end they only had 330 CRANK hp from the factory, even if it is the edelbrock kit though, you do not have 400rwhp.