Shitty Drivability
08-16-2007, 06:33 PM
#1
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Shitty Drivability Hey guys. I did a head/cam swap a month ago and everything was good. My setup:
TEA TFS heads, assembled
228/230 cam
LS6 chain and oil pump
caddy lifters
TFS pushrods
Harland Sharp rockers
ARP head studs
ARP crank pulley
ARP rod bolts
SLP pulley
MTI lid
XS stainless headers
no cats
true duals
Lucas 42# injectors
Anyways. I've been tuning it and getting the idle and AFR in order, and it started to get REALLY hot down here in Houston(like 150* IAT), and the car started to drive like ****. At first it would barely idle, and I figured it was because the pcm was pulling timing.
Then it started missing at WOT high rpm. Now it won't even go above 4500 rpm. WILL NOT GO, even in neutral. It's almost like im hitting a rev limiter.
It sounds very weak and missing, but it's not throwing any codes relevant to the problem.
It's pulling 15" of vacuum at idle, so I think the valvetrain is ok.
Maybe a fuel pump? How can I diagnose this?
Thanks for everyone's help.
TEA TFS heads, assembled
228/230 cam
LS6 chain and oil pump
caddy lifters
TFS pushrods
Harland Sharp rockers
ARP head studs
ARP crank pulley
ARP rod bolts
SLP pulley
MTI lid
XS stainless headers
no cats
true duals
Lucas 42# injectors
Anyways. I've been tuning it and getting the idle and AFR in order, and it started to get REALLY hot down here in Houston(like 150* IAT), and the car started to drive like ****. At first it would barely idle, and I figured it was because the pcm was pulling timing.
Then it started missing at WOT high rpm. Now it won't even go above 4500 rpm. WILL NOT GO, even in neutral. It's almost like im hitting a rev limiter.
It sounds very weak and missing, but it's not throwing any codes relevant to the problem.
It's pulling 15" of vacuum at idle, so I think the valvetrain is ok.
Maybe a fuel pump? How can I diagnose this?
Thanks for everyone's help.
08-16-2007, 09:35 PM
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TPS has been normal on the logs. WOT is about 96%, and idle is 0%.
Also, if I cold start it, the car will buck SO BAD while trying to get up to say...30, it's almost painful to my neck, and I'm not exagerating at all. Almost breaking the tires loose, the bucking is so bad.
Anyone else have any input?
Also, if I cold start it, the car will buck SO BAD while trying to get up to say...30, it's almost painful to my neck, and I'm not exagerating at all. Almost breaking the tires loose, the bucking is so bad.
Anyone else have any input?
08-17-2007, 12:33 AM
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Originally Posted by edcmat-l1
Did you disable the LT fuel trim? Tried resetting the fuel trims? Have a log you can post? What software you using?
Provide some more info and try posting in the scan and tune section.
Provide some more info and try posting in the scan and tune section.
I have reset the fuel trims. Thing is, I actually had the car running very well. Then it got REALLY hot in Houston and the car started to idle like crap. I dismissed this as the PCM pulling timing because of the heat. Then the idle got worse and the higher rpm sputtering and now it will sputter at any rpm and high load(WOT).
I will be putting a fuel pressure gauge on the car tomorrow. I can only hope that would be my ONLY problem. I would love to upgrade to a Racetronix PnP pump and have no more problems. Aren't they only like $230 now?
EDIT- I'm using HPT.
Last edited by 3.4camaro; 08-17-2007 at 12:40 AM.
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08-17-2007, 01:19 AM
#8
The tune we are tossing back and forth is for stock injectors,I told ya to tell me before you popped those 42s in there, just looked at logs you sent and your cruise is 30-40% trimmed - guessing it MUST be injectors already swapped
edit
feel free to post your tune, just keep the spreadsheets I gave you to yourself.
edit
feel free to post your tune, just keep the spreadsheets I gave you to yourself.
Last edited by Frost; 08-17-2007 at 01:28 AM.
The computer compensates, right? Thats what its for, right? (sarcastic).......
08-17-2007, 11:20 AM
#13
I'm sure the poster knows that these injectors require changes and I'm sure that this was some mis-communication between the two of us via PM and email. Looking at his trimming and his O2s hit 998-1002mV at WOT tell me.... well, you know. 
He has a pretty rad setup for a daily driver, I'm just trying to help him get it moving 
He has a pretty rad setup for a daily driver, I'm just trying to help him get it moving
08-17-2007, 11:41 AM
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I did some changes to the tune for the injectors. I changed the min pulse width and the flow rate vs. KPA. I'm not an idiot. 
Anyways. I did some of the changes and sent it back to you(Frost), maybe they got changed back for some reason, and that's where my problems lie. Anyways, I'm going to load my new tune and we'll see whatsup.
Anyways. I did some of the changes and sent it back to you(Frost), maybe they got changed back for some reason, and that's where my problems lie. Anyways, I'm going to load my new tune and we'll see whatsup.