Just Bought 99 c5. having accel. issues
Thread Starter
Cruising
Joined: Aug 2008
Posts: 12
Likes: 0
Just Bought 99 c5. having accel. issues
Seems like when I accelerate, i get instances where the engine seems to bog for a split second, making for uneven acceleration. Usually in the lower gears. Also, when i accelerate somewhat harder than normal, i smell exhaust in the cab. I dont know if this is relevant, but it may help. Also, I was told upon buying it that the 99 c5 6 speed's exhaust was swapped out for a z06 exhaust. Just did oil change and injector cleaning, still seems to idle a little harsh sometimes, and like I said, uneven acceleration. Any takers??
Thanks alot guys. Much appreciated.
Thanks alot guys. Much appreciated.
Tech Contributor
Joined: Sep 2005
Posts: 1,731
Likes: 82
From: New Market AL
It's hard to make a solid diagnosis off just that description, but it sounds similar to my '94 Corvette when I first bought it. I changed plugs and wires and it smoothed out big time. Any idea how many other upgrades it might have? Has the tune been modified? Does it show any codes on the diagnostic information center (DIC). Do a search on displaying diagnostic codes if you haven't already done that.
Thread Starter
Cruising
Joined: Aug 2008
Posts: 12
Likes: 0
84k miles. just z06 brakes and exhaust as far as i know. Not too sure about tuning, he didnt mention it. no codes beside my ebtctm that popped up. no engine light. yea, I think Ill start with the plugs and wires. Thank you guys SOO much. Any other ideas would be appreciated. Good to know you guys take care of eachother.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Take a quick look at the pcv valve connection tube to the intake. Holes will appear in it, especially on the bottom of it, out of sight. After that, wires, plugs, spray clean the maf.
Melting Slicks
Joined: Aug 2006
Posts: 2,167
Likes: 11
From: Powell TN
Cruise-In VIII Veteran
84k miles. just z06 brakes and exhaust as far as i know. Not too sure about tuning, he didnt mention it. no codes beside my ebtctm that popped up. no engine light. yea, I think Ill start with the plugs and wires. Thank you guys SOO much. Any other ideas would be appreciated. Good to know you guys take care of eachother.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Read and post your DTCs. When you feel it hesitate, take a look at the Check Engine Light (CEL) and see if it is flashing. That would indicate that you have an engine misfire.
You can check the air filter and clean the MAF and TB with MAF cleaner. Just sprap it in the MAF and let the solvent evaproate.
Yes,,
the PCV pluming can deteroriate and thats something that should be checked.
BC
You can check the air filter and clean the MAF and TB with MAF cleaner. Just sprap it in the MAF and let the solvent evaproate.
Yes,,
the PCV pluming can deteroriate and thats something that should be checked.BC
Thread Starter
Cruising
Joined: Aug 2008
Posts: 12
Likes: 0
2 questions.
Since Ive never dealt with an LS1 before, and before i start spraying random parts, is there a link to a forum that explains where I can check the pcv, and same with how to clean the MAF sensors. No engine lights, just feels like Im getting robbed of power horribly and wasting gas like crazy. Im thinking too that the timing may be off a little? I had a 4.3l chevy that used to do about the same thing when the distributor cap spun out of place a little, but Ive heard that c5 engines are capless. I dont know, I guess its time to dive head first into this one!!
Since Ive never dealt with an LS1 before, and before i start spraying random parts, is there a link to a forum that explains where I can check the pcv, and same with how to clean the MAF sensors. No engine lights, just feels like Im getting robbed of power horribly and wasting gas like crazy. Im thinking too that the timing may be off a little? I had a 4.3l chevy that used to do about the same thing when the distributor cap spun out of place a little, but Ive heard that c5 engines are capless. I dont know, I guess its time to dive head first into this one!!
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Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Yeah, there is no distributor and no timing that you can adjust without an interface and software, or other devices like a TechII Scan Tool. Yes, as Bill suggested, you should pull the codes.
Pro
Joined: Oct 2004
Posts: 538
Likes: 0
From: Edmond Ok
You said wasting gas, what kind of MPG are you getting?
no codes at all?
I would recommend you invest in a set of service manuals, you can buy new in the $100 - 150 range or go to ebay or try the forum used part site.
Have you tried taking it off traction control to see what it does. I was currious in your first post you said you get instances where it bogs down. If the computer senses wheel spin it trims your throttle. Be carefull when you get on it hard without traction control.
Simply tune up, plugs,filters, wires, pvc is not a bad place to start imo.
Good luck
no codes at all?
I would recommend you invest in a set of service manuals, you can buy new in the $100 - 150 range or go to ebay or try the forum used part site.
Have you tried taking it off traction control to see what it does. I was currious in your first post you said you get instances where it bogs down. If the computer senses wheel spin it trims your throttle. Be carefull when you get on it hard without traction control.
Simply tune up, plugs,filters, wires, pvc is not a bad place to start imo.
Good luck
Melting Slicks
Joined: Aug 2006
Posts: 2,167
Likes: 11
From: Powell TN
Cruise-In VIII Veteran
Like dgeng said, did you take the traction control off when you got on it? That would cause the problems you are having.
Thread Starter
Cruising
Joined: Aug 2008
Posts: 12
Likes: 0
i believe the codes were 2250. maybe if I just unplug the module altogether then it will fix this, until I get the absfixer guys to rebuild it. Also, my tires were low in air, and when i filled them all up, it helped alot, but i can still feel the hiccup in the power when accelerating. I tend to hit traffic alot, which SUCKS! So alot of stop go for the last month. But we can start with the plugs n wires and go from there. Like you said, couldnt hurt since my miles are getting up there anyway. WOO! excited to get my power back!!!
Advanced
Joined: Nov 2007
Posts: 70
Likes: 0
From: San Mateo Ca
yeah go for the plugs and wires. I got the msd from autozone for 63 and the copper plugs and they made a world of difference on my car. I have a 97 6 speed i got with 108k and after I did that the biggest problem I had was the runflats. Switch to a set of bfg kdw's or extreme performance summer tire and you will feel a huge difference. I also have red paint but calling them zo6 brakes sounds so much bettter
Thread Starter
Cruising
Joined: Aug 2008
Posts: 12
Likes: 0
haha, well they are slotted rotors and whatnot, but youre right, z06 makes it sound... spiffy haha. And you guys were right, one of the wires was arc-ing and causing it to run really rough and burn excess fuel. Excellent call guys, thanks a ton!!!!