DESPERATE! new head cam package will not start
Thread Starter
Launching!
Joined: Nov 2003
Posts: 272
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DESPERATE! new head cam package will not start got my car back together... 97 corvette
ms4
prc heads
underdrive
ls6 intake
headers
car cranked GREAT first time and idled great, ran it to the top of the road. idled great, but when i got it back to the house it would not find idle and just kind of ran crappy - missing, puking, bucking ... but now will not do anything. it is deader the hell and throwing p1571 p0171 p0174 will not even start
please help!!!!
ms4
prc heads
underdrive
ls6 intake
headers
car cranked GREAT first time and idled great, ran it to the top of the road. idled great, but when i got it back to the house it would not find idle and just kind of ran crappy - missing, puking, bucking ... but now will not do anything. it is deader the hell and throwing p1571 p0171 p0174 will not even start
please help!!!!
What's funny is the initial start working. Kind of says the
original state of tune was kind of OK but it's (mis)learned
something - like idle trims, fuel trims etc. Though start
should be open loop regardless. The gross lean codes say
either the O2 sensors are left unhooked or bugger cold and
this would for sure whack closed loop (+25 LTFTs before
this code sets) and who knows, maybe corrupt startup
fueling?
original state of tune was kind of OK but it's (mis)learned
something - like idle trims, fuel trims etc. Though start
should be open loop regardless. The gross lean codes say
either the O2 sensors are left unhooked or bugger cold and
this would for sure whack closed loop (+25 LTFTs before
this code sets) and who knows, maybe corrupt startup
fueling?
Thread Starter
Launching!
Joined: Nov 2003
Posts: 272
Likes: 0
Originally Posted by jimmyblue
What's funny is the initial start working. Kind of says the
original state of tune was kind of OK but it's (mis)learned
something - like idle trims, fuel trims etc. Though start
should be open loop regardless. The gross lean codes say
either the O2 sensors are left unhooked or bugger cold and
this would for sure whack closed loop (+25 LTFTs before
this code sets) and who knows, maybe corrupt startup
fueling?
original state of tune was kind of OK but it's (mis)learned
something - like idle trims, fuel trims etc. Though start
should be open loop regardless. The gross lean codes say
either the O2 sensors are left unhooked or bugger cold and
this would for sure whack closed loop (+25 LTFTs before
this code sets) and who knows, maybe corrupt startup
fueling?
car is tuned by texas speed... i got their all inclusive package.
now the car will not even start.... only code is p1571 h c
Thread Starter
Launching!
Joined: Nov 2003
Posts: 272
Likes: 0
Originally Posted by See5
i can clear the codes all day long and it will still do the same thing... only code that it is throwing now is p1571
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Sounds like a huge vacuum leak to me. So, just to be clear, you bought the heads, cam, associated hdw and a tuned pcm for your 97 vette from TSP? All things considered TSP is a good crew, a vacuum leak would play this kind of havoc. Do you still have the stock PCV system or did you upgrade to the LS6 style? Catch can, breathers...details. "Works" fine-what kind of idle are we talking about 1k+ after a proper warm up? That's not good. So you drive down the road and your Fuel Trims are going crazy and set the codes. Some sort of leak, weather exhaust or vacuum.
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Originally Posted by Doc
Sounds like a huge vacuum leak to me. .
i posted that same idea in his other thread in internal forum. With each bank throwing a lean code there has to be a huge vacuum leak. Thread Starter
Launching!
Joined: Nov 2003
Posts: 272
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Originally Posted by jimmyblue
Nothing going on with the security light etc. is there? Can you
verify fuel pressure and presence of spark (even if not right, at
least showing up)?
verify fuel pressure and presence of spark (even if not right, at
least showing up)?
yeah, my security light has been on for two years. you think it could be from that?
Thread Starter
Launching!
Joined: Nov 2003
Posts: 272
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Originally Posted by Doc
Sounds like a huge vacuum leak to me. So, just to be clear, you bought the heads, cam, associated hdw and a tuned pcm for your 97 vette from TSP? All things considered TSP is a good crew, a vacuum leak would play this kind of havoc. Do you still have the stock PCV system or did you upgrade to the LS6 style? Catch can, breathers...details. "Works" fine-what kind of idle are we talking about 1k+ after a proper warm up? That's not good. So you drive down the road and your Fuel Trims are going crazy and set the codes. Some sort of leak, weather exhaust or vacuum.
Dude, I hope you won't take this the wrong way but I can't help but think what an amazing time we live in where this firehose of information exists that makes us feel comfortable about diving into our motors yet, at the same time shawdos the simplest of truths.
The PCV system is the Positive CrankCase Ventilation system. In a nutshell, your motor is made up of 3 main chambers, main block and the two respective heads. I guess you could add the intake too. The PCV system of hoses and a valve "equalizes" these zones relative pressures so to speak in the most elementary of explanations. A leak in this system(s) will add unfiltered, unmetered air to your engine. A stock, non calibrated pcm might.../I have personally witnessed will "idle" @ around 15k+. It will surge like an old *****. Smaller but equally frustrating leaks will fool you/ your tuner into thinking that the car wants "...this..." until these issues are resolved you will chase your tail in perpeptude.
Given your situation where you have a packaged tune setup for the physical package you bought, this only reinforces this logic path of the grande and not so sexy leak you are fighting.
Next question, did you use a calibrated torque wrench with the factory aprroved pattern on the intake? New intake manifold gaskets?
The PCV system is the Positive CrankCase Ventilation system. In a nutshell, your motor is made up of 3 main chambers, main block and the two respective heads. I guess you could add the intake too. The PCV system of hoses and a valve "equalizes" these zones relative pressures so to speak in the most elementary of explanations. A leak in this system(s) will add unfiltered, unmetered air to your engine. A stock, non calibrated pcm might.../I have personally witnessed will "idle" @ around 15k+. It will surge like an old *****. Smaller but equally frustrating leaks will fool you/ your tuner into thinking that the car wants "...this..." until these issues are resolved you will chase your tail in perpeptude.
Given your situation where you have a packaged tune setup for the physical package you bought, this only reinforces this logic path of the grande and not so sexy leak you are fighting.
Next question, did you use a calibrated torque wrench with the factory aprroved pattern on the intake? New intake manifold gaskets?
Thread Starter
Launching!
Joined: Nov 2003
Posts: 272
Likes: 0
Originally Posted by Doc
Dude, I hope you won't take this the wrong way but I can't help but think what an amazing time we live in where this firehose of information exists that makes us feel comfortable about diving into our motors yet, at the same time shawdos the simplest of truths.
The PCV system is the Positive CrankCase Ventilation system. In a nutshell, your motor is made up of 3 main chambers, main block and the two respective heads. I guess you could add the intake too. The PCV system of hoses and a valve "equalizes" these zones relative pressures so to speak in the most elementary of explanations. A leak in this system(s) will add unfiltered, unmetered air to your engine. A stock, non calibrated pcm might.../I have personally witnessed will "idle" @ around 15k+. It will surge like an old *****. Smaller but equally frustrating leaks will fool you/ your tuner into thinking that the car wants "...this..." until these issues are resolved you will chase your tail in perpeptude.
Given your situation where you have a packaged tune setup for the physical package you bought, this only reinforces this logic path of the grande and not so sexy leak you are fighting.
Next question, did you use a calibrated torque wrench with the factory aprroved pattern on the intake? New intake manifold gaskets?
The PCV system is the Positive CrankCase Ventilation system. In a nutshell, your motor is made up of 3 main chambers, main block and the two respective heads. I guess you could add the intake too. The PCV system of hoses and a valve "equalizes" these zones relative pressures so to speak in the most elementary of explanations. A leak in this system(s) will add unfiltered, unmetered air to your engine. A stock, non calibrated pcm might.../I have personally witnessed will "idle" @ around 15k+. It will surge like an old *****. Smaller but equally frustrating leaks will fool you/ your tuner into thinking that the car wants "...this..." until these issues are resolved you will chase your tail in perpeptude.
Given your situation where you have a packaged tune setup for the physical package you bought, this only reinforces this logic path of the grande and not so sexy leak you are fighting.
Next question, did you use a calibrated torque wrench with the factory aprroved pattern on the intake? New intake manifold gaskets?
oh well i knew that there was vetilation for the motor, just never really had to deal with it... intake was brand new as well as the gaskets. but was taken off and put on about 7 times due to a head issue.