ls1 rough start
ls1 rough start Ive been having issues with my ls1 camaro starting lately. I had my buddy from a Chevrolet dealership look at it and use their fancy scan tools to check it out. At first my camaro would attempt to start once, but if it failed to start it would refuse to start for at least 24 hours. We ended up finding a chaffed wire to the temp sensor that goes into the head and replaced that.
Now when i attempt to start it i MUST give it some gas or it just refuses to start.
in the process my buddy checked and all were good.....
-Fuel pump, fuel regular and fuel pressure
-Starter and ignition
-Relays, there were no hidden check engine codes that only the dealership can see
- no missfires or anything like that.
Are there any sensors that would cause this rough start?
Now when i attempt to start it i MUST give it some gas or it just refuses to start.
in the process my buddy checked and all were good.....
-Fuel pump, fuel regular and fuel pressure
-Starter and ignition
-Relays, there were no hidden check engine codes that only the dealership can see
- no missfires or anything like that.
Are there any sensors that would cause this rough start?
TECH Regular
Joined: Dec 2011
Posts: 423
Likes: 1
From: Wildomar, CA
The attempt to start, then shutdown makes me think security system is a possibility. Anything with the security light? I'd try making a VATS bypass just to see, it only cost me $10 to make mine. Worst case scenario you rule it out.
Clean the MAF maybe? another cheap and easy idea. Everything you can rule out is one step closer
Clean the MAF maybe? another cheap and easy idea. Everything you can rule out is one step closer
The security light never comes on except for when i turn the key to the on position. It disappears shortly after and does not come on again.
I have not messed with my MAF at all. perhaps a cleaning would be a shot worth taking.
I have not messed with my MAF at all. perhaps a cleaning would be a shot worth taking.
Have you tried turning the key into the ON position a few times to see if starts better? THat should help pressurize the fuel line/rails and help you eliminate the fuel part of the equation.
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Well i just replaced the fuel filter (the old one was quite dirty and has been on there for wayyy too long) I will see if anything changes when i drive it to work tomorrow.
It runs like pure ****. During the first 5-10 seconds it runs as if it has a big cam in it (stock cam), then it builds the idle to around 1,000 rpms, then jumps to around 1300 rpms. Sometimes a little higher. If i drive it within a minute of idle its running very rich (i guess from all the pedal pumping required to get it to start). After all the unburned fuel is out of the exhaust it drives pretty smooth.
I have tried this, it seems to be getting fuel but not enough to start. I know the system is not leaking because i had it pressure tested @ 60psi and it was holding pressure just fine.
-I just replaced a bad clutch pedal position sensor as well.
Does anyone know what would make my car idle so high? perhaps i need to have it retuned. Recently i swapped out an ebay 92mm throttle body for a Nick Williams 92mm Throttle Body and it hasent idled quite right since the swap. But i had a few other issues from the idle that have been solved since then so im not sure.
It runs like pure ****. During the first 5-10 seconds it runs as if it has a big cam in it (stock cam), then it builds the idle to around 1,000 rpms, then jumps to around 1300 rpms. Sometimes a little higher. If i drive it within a minute of idle its running very rich (i guess from all the pedal pumping required to get it to start). After all the unburned fuel is out of the exhaust it drives pretty smooth.
-I just replaced a bad clutch pedal position sensor as well.
Does anyone know what would make my car idle so high? perhaps i need to have it retuned. Recently i swapped out an ebay 92mm throttle body for a Nick Williams 92mm Throttle Body and it hasent idled quite right since the swap. But i had a few other issues from the idle that have been solved since then so im not sure.
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TECH Enthusiast
Joined: Nov 2012
Posts: 555
Likes: 0
From: NearHouston, TX
I apoligize if this msg is duplicated, thought I responded but can't find it. Anyway I had a friend with very similar problems recently and it turned out to be bad gasoline she just filled up with, but obviously you'd rule that out if you didn't fill up before problems, and hopefully someone didn't pour something in your gas tank or something stupid like that. They drained her tank, refilled and problem solved.
Regarding fuel pump troubleshooting, I was going thru a similar episode a couple years ago and it turned out to be a oily MAF from the oiled K&N filter I was running. Anyway I installed a $18 gas pressure gauge on the stock fuel rail, pressure was there, but I left it in and is a good tool for troubleshooting.
If it was the VATS, I'm pretty sure the key would never turn over if your ignition is stock, unless you bypassed module and went straight from ignition to starter. My security light came on a few times, but stayed on while driving, then just stranded me at my daughter's gym! Good that you are bypassing the VATS tho, a worn key pellet could be a life or death situation. Good luck hope it's resolved.
Regarding fuel pump troubleshooting, I was going thru a similar episode a couple years ago and it turned out to be a oily MAF from the oiled K&N filter I was running. Anyway I installed a $18 gas pressure gauge on the stock fuel rail, pressure was there, but I left it in and is a good tool for troubleshooting.
If it was the VATS, I'm pretty sure the key would never turn over if your ignition is stock, unless you bypassed module and went straight from ignition to starter. My security light came on a few times, but stayed on while driving, then just stranded me at my daughter's gym! Good that you are bypassing the VATS tho, a worn key pellet could be a life or death situation. Good luck hope it's resolved.
I apoligize if this msg is duplicated, thought I responded but can't find it. Anyway I had a friend with very similar problems recently and it turned out to be bad gasoline she just filled up with, but obviously you'd rule that out if you didn't fill up before problems, and hopefully someone didn't pour something in your gas tank or something stupid like that. They drained her tank, refilled and problem solved.
Regarding fuel pump troubleshooting, I was going thru a similar episode a couple years ago and it turned out to be a oily MAF from the oiled K&N filter I was running. Anyway I installed a $18 gas pressure gauge on the stock fuel rail, pressure was there, but I left it in and is a good tool for troubleshooting.
If it was the VATS, I'm pretty sure the key would never turn over if your ignition is stock, unless you bypassed module and went straight from ignition to starter. My security light came on a few times, but stayed on while driving, then just stranded me at my daughter's gym! Good that you are bypassing the VATS tho, a worn key pellet could be a life or death situation. Good luck hope it's resolved.
Regarding fuel pump troubleshooting, I was going thru a similar episode a couple years ago and it turned out to be a oily MAF from the oiled K&N filter I was running. Anyway I installed a $18 gas pressure gauge on the stock fuel rail, pressure was there, but I left it in and is a good tool for troubleshooting.
If it was the VATS, I'm pretty sure the key would never turn over if your ignition is stock, unless you bypassed module and went straight from ignition to starter. My security light came on a few times, but stayed on while driving, then just stranded me at my daughter's gym! Good that you are bypassing the VATS tho, a worn key pellet could be a life or death situation. Good luck hope it's resolved.
Last edited by Tzone21; Apr 1, 2013 at 09:26 PM.
I bought a MAF cleaner spray from Autozone and cleaned it up good along with the connectors. It wasn't too dirty but could use a cleaning regardless. I cleaned the screen as well and put it back on the car after drying. I drove the car around a bit seeing if there was any difference and i did not notice any. The idle was still just as high as before.
Would cleaning the MAF require some time or would it show instant results?
Would cleaning the MAF require some time or would it show instant results?
yep, been there...sometimes it would start and run, then die suddenly when driving/would not restart. Replace IGN relay and fixed it for awhile, but as it turned out in my case, the fuse block itself had a loose contact for the IGN relay.
TECH Enthusiast
Joined: Nov 2012
Posts: 555
Likes: 0
From: NearHouston, TX
The cleaning of the MAF should be quick result if that is the problem. Do you have the stock 78mm or the SLP 85mm MAF?. Does it change when you disconnect the MAF while running? I didn't see any codes reported on the thread, did your buddy test the codes, if not you can go to autozone and they can see what is happening if a sensor or something.
The cleaning of the MAF should be quick result if that is the problem. Do you have the stock 78mm or the SLP 85mm MAF?. Does it change when you disconnect the MAF while running? I didn't see any codes reported on the thread, did your buddy test the codes, if not you can go to autozone and they can see what is happening if a sensor or something.
I actually replaced the IGN relay a lil while ago and that did not do anything. My alternator just went bad so i swapped it with a brand new one (lifetime warranty) and its running much smoother surprisingly.