stock LS1 getting 10mpg??? WTF
03-14-2007, 09:17 PM
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stock LS1 getting 10mpg??? WTF 10 mpg...
idles like doo-doo
had a P0307 code a few weeks ago... only once, erased & never came back
02's are swiching fine
MAP @ idle is 3.9psi ish (which i think is really low, but im not sure what spec is)
car only has SLP lid & Magnaflow catback
changed plugs & wires, fuel filter, pcv valve, air filter about 8 months & 13,000 miles ago
any ideas???
ive gone over a bunch of sh*t but im wondering what im forgetting
idles like doo-doo
had a P0307 code a few weeks ago... only once, erased & never came back
02's are swiching fine
MAP @ idle is 3.9psi ish (which i think is really low, but im not sure what spec is)
car only has SLP lid & Magnaflow catback
changed plugs & wires, fuel filter, pcv valve, air filter about 8 months & 13,000 miles ago
any ideas???
ive gone over a bunch of sh*t but im wondering what im forgetting
Last edited by 1baddls1; 03-14-2007 at 10:04 PM.
03-14-2007, 09:27 PM
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I'd double check that all of your wires are on good. Also, maybe test and make sure your fuel pressure is correct and maybe check injectors to see if one is stuck open...
03-14-2007, 09:27 PM
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WTF is a 307 code, I dont see anything 307 in my list of codes?
Your MAP reading at idle is correct for a stock car. I would be searching for a vacuum leak or if you still have EGR connected I would check that over too, leakt EGR valves can cause a car to idle like crap. Are you experiencing any knock retard? Knock retard can kill mileage. If you havent checked yet scan and see. Also test the spark strength at the plug boot by pulling the boot off the plug and hold it to the block and see if the spark looks weak, if you find a weak one that coil may be bad.
Your MAP reading at idle is correct for a stock car. I would be searching for a vacuum leak or if you still have EGR connected I would check that over too, leakt EGR valves can cause a car to idle like crap. Are you experiencing any knock retard? Knock retard can kill mileage. If you havent checked yet scan and see. Also test the spark strength at the plug boot by pulling the boot off the plug and hold it to the block and see if the spark looks weak, if you find a weak one that coil may be bad.
03-14-2007, 09:37 PM
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Originally Posted by jamesSS
check your gas cap. mine doesnt even tighen up, giving me about 12 MPG. im getting a new cap 2marrow. just a thought. hope you figure it out. good luck.
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03-14-2007, 09:42 PM
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Originally Posted by 1baddls1
P0307
misfire cylinder # 7
misfire cylinder # 7
03-14-2007, 09:47 PM
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Originally Posted by 97MysticZ
I'd double check that all of your wires are on good. Also, maybe test and make sure your fuel pressure is correct and maybe check injectors to see if one is stuck open...
fuel system will certianly need a good checking out
Originally Posted by brad8266
I would be searching for a vacuum leak or if you still have EGR connected I would check that over too, leakt EGR valves can cause a car to idle like crap.
Are you experiencing any knock retard? Knock retard can kill mileage. If you havent checked yet scan and see.
Also test the spark strength at the plug boot by pulling the boot off the plug and hold it to the block and see if the spark looks weak, if you find a weak one that coil may be bad.
Are you experiencing any knock retard? Knock retard can kill mileage. If you havent checked yet scan and see.
Also test the spark strength at the plug boot by pulling the boot off the plug and hold it to the block and see if the spark looks weak, if you find a weak one that coil may be bad.
no knock retard - scan car often (with real time data too)
spark strength... hmm
03-14-2007, 09:48 PM
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Originally Posted by brad8266
Something may be wrong with that cylinder, #7 is known to be the cylinder to go bad on the LS1. Do a quick compression test to compare 7 to another 1 or 2 cylinders.
God help me
comp test will be done when full bolt ons get swapped over in a few weeks
03-14-2007, 10:04 PM
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Originally Posted by JBsZ06
This may sound stupid but check the pcv valve.
Made a huge difference in mileage and performance on my car.
I don't know why but it did.
HTH
JB
Made a huge difference in mileage and performance on my car.
I don't know why but it did.
HTH
JB
doesnt hurt to double & triple check everything though
any other insight?
03-14-2007, 10:31 PM
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I ve done a lot of searching on this subject and sometimes the hoses (that connect pcv valve etc) can leak on the underside and that would create a vacuum leak...Not easy to find spraying starter fluid....I read that guys intermitently get lucky and find the leak on the underside...of hose...
Just a suggestion but checking for a vacuum leak even on the underside of on the hose connecting the pcv to the engine etc....as some ls1owners have mentioned they found an issue..
The vacuum leak would set the car to a lean mixture...setting off knock sensors and then the pcm would dump fuel into the engine to control knock...
At least that scenerio was what was happening with me and when I fixed the leak..the lean condition went away...the pcm stopped dumping in fuel to compensate and the car got considerably better gas mileage...
This is just what I saw recently and the gas mileage went up...and the car drove better too.
Good luck
Just a suggestion but checking for a vacuum leak even on the underside of on the hose connecting the pcv to the engine etc....as some ls1owners have mentioned they found an issue..
The vacuum leak would set the car to a lean mixture...setting off knock sensors and then the pcm would dump fuel into the engine to control knock...
At least that scenerio was what was happening with me and when I fixed the leak..the lean condition went away...the pcm stopped dumping in fuel to compensate and the car got considerably better gas mileage...
This is just what I saw recently and the gas mileage went up...and the car drove better too.
Good luck
03-15-2007, 05:55 AM
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Originally Posted by JBsZ06
I ve done a lot of searching on this subject and sometimes the hoses (that connect pcv valve etc) can leak on the underside and that would create a vacuum leak...Not easy to find spraying starter fluid....I read that guys intermitently get lucky and find the leak on the underside...of hose...
Just a suggestion but checking for a vacuum leak even on the underside of on the hose connecting the pcv to the engine etc....as some ls1owners have mentioned they found an issue..
The vacuum leak would set the car to a lean mixture...setting off knock sensors and then the pcm would dump fuel into the engine to control knock...
At least that scenerio was what was happening with me and when I fixed the leak..the lean condition went away...the pcm stopped dumping in fuel to compensate and the car got considerably better gas mileage...
This is just what I saw recently and the gas mileage went up...and the car drove better too.
Good luck
Just a suggestion but checking for a vacuum leak even on the underside of on the hose connecting the pcv to the engine etc....as some ls1owners have mentioned they found an issue..
The vacuum leak would set the car to a lean mixture...setting off knock sensors and then the pcm would dump fuel into the engine to control knock...
At least that scenerio was what was happening with me and when I fixed the leak..the lean condition went away...the pcm stopped dumping in fuel to compensate and the car got considerably better gas mileage...
This is just what I saw recently and the gas mileage went up...and the car drove better too.
Good luck
also recently cleaned the MAF
03-15-2007, 04:50 PM
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Originally Posted by Specialized
If you have taken off your TB, I would think its the gasket (oring). Get a new one and swap it out, be sure to keep the mating surfaces clean.
anyone else have any ingenius ideas???
