WTF :bang:? New 408 Problems
#1
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
WTF :bang:? New 408 Problems
Ok so as some of u know i wrapped up my first LS build a while ago. So the motor runs good and has now major problems that i can find. Heres what is wrong. 1: So i went to start my car tonight after it had sat for probly 7-8 hours. It started right up then died. So i restarted it and it sputtered for a sec then idled like normal. So i drove it to a gas station thats was like 1 mile away ran inside for a couple minutes came out and started it and it died. So i restarted it and it sputtered and then idled. So is this normal on cold starts? I read somewhere on here a while back that camed cars sometimes do this, so i just want to know if this is something to worry about?
2: So the next issue is occasiinally when i do a wot pull the motor will just fall on its face around 3500 RPM's and a check engine light will flash and so will the low oil light, they flash on for like 2 seconds then turn off leaving no codes. Now this is only at wide open throttle and it doesnt do this at all if i accelerate gently. Now the car isnt fully tuned but it has a base tune and my tuner said its safe to drive its just not going to be making maximum power. I suspect that this might be a bad cat because i knew my stock cat was going out when i bought the car a year ago. So is this a symptom of a bad cat? If not what in the hell is it?
3: The next issue that has been driving me CRAZY is the ASR Off light, i mean it comes on randomly when im driving and i cant turn it off. It eventually shuts itself off. I mean i cant figure out whats causing it. The tires are stock size and my rear end is the stock ten bolt. Any ideas guys?
So thats the issues in a nut shell. Oh and im about ready to replace my entire exhaust system with tsp true duals and there 1 7/8" long tubes as well as improving my entire drive train.
2: So the next issue is occasiinally when i do a wot pull the motor will just fall on its face around 3500 RPM's and a check engine light will flash and so will the low oil light, they flash on for like 2 seconds then turn off leaving no codes. Now this is only at wide open throttle and it doesnt do this at all if i accelerate gently. Now the car isnt fully tuned but it has a base tune and my tuner said its safe to drive its just not going to be making maximum power. I suspect that this might be a bad cat because i knew my stock cat was going out when i bought the car a year ago. So is this a symptom of a bad cat? If not what in the hell is it?
3: The next issue that has been driving me CRAZY is the ASR Off light, i mean it comes on randomly when im driving and i cant turn it off. It eventually shuts itself off. I mean i cant figure out whats causing it. The tires are stock size and my rear end is the stock ten bolt. Any ideas guys?
So thats the issues in a nut shell. Oh and im about ready to replace my entire exhaust system with tsp true duals and there 1 7/8" long tubes as well as improving my entire drive train.
#3
TECH Senior Member
iTrader: (71)
I wouldn't be getting on it with a base tune... You're asking for big trouble. Load is good to seat the rings but i wouldn't advise anything past 4000 rpms or so. You have zero clue what your af looks like.
Are you sure you have enough oil?
The dying on the first start should be fixed with a proper tune.
Take it easy until you get a full tune and check everything man.
Are you sure you have enough oil?
The dying on the first start should be fixed with a proper tune.
Take it easy until you get a full tune and check everything man.
#4
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
I wouldn't be getting on it with a base tune... You're asking for big trouble. Load is good to seat the rings but i wouldn't advise anything past 4000 rpms or so. You have zero clue what your af looks like.
Are you sure you have enough oil?
The dying on the first start should be fixed with a proper tune.
Take it easy until you get a full tune and check everything man.
Are you sure you have enough oil?
The dying on the first start should be fixed with a proper tune.
Take it easy until you get a full tune and check everything man.
#6
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
Well since i three w a couple rods on my old motor i didnt want to take any chancea of puting anythingback on the motor that could have metal on it. Oil preasure is strong and it drives smooth. When it lost power it droped from like 60psi to a little above 40psi and when i shifted and gently accelerated to mantain speed the oil preasure went back up. Like i said this is my first build and i cant think of what could cause this. Everything seems to check out from what i can tell. Any things i should check?
Trending Topics
#8
TECH Enthusiast
iTrader: (17)
Personally I wouldn't drive it until it gets dynoed. Your just asking for trouble, sounds like most of the issues are in your tune. Even if you tell yourself I won't beat on it you will still find yourself getting on it lightly, still not good with a half *** tune. If you keep doing WOT with a half *** tune, your next thread will be I blew my motor up.... If you have another vehicle drive it...period....
As far as your oil pressure it's good still, but I'm curious as to why it drops 20??? When you say looses power, do you mean it just stumbles or it physically has the power cut from the motor then comes back in?? If so could very well be a short or a pinched wire.
As far as your oil pressure it's good still, but I'm curious as to why it drops 20??? When you say looses power, do you mean it just stumbles or it physically has the power cut from the motor then comes back in?? If so could very well be a short or a pinched wire.
#9
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
When the oil pressure drops it is when the engine loses power. Like the car is idling right now at like 45psi but with load it raises to 60. Basically when i say that the engine loses power i mean it just stops accelerating like it just hit a wall and the rpms drop about 500rpms. And no its not tge rev limiter because the rev limiter is set at 4k. My tuner reworked the maf and told me i could drive it around it just wouldnt make peak power. So ur saying i shouldnt drive it until it gets a full dyno tune.
#11
TECH Regular
Thread Starter
Join Date: Dec 2012
Location: San Diego
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
Hes been tuning LS cars for about as long as they have been around. He is highly recomended here in southern California. And what exactly is a wide band?
#12
TECH Enthusiast
iTrader: (17)
Wideband oxygen sensor, it basically measures your exhaust fumes to tell if your car is running rich or lean, in short. They are very accurate for timing vehicles and getting the fuel maps and parameters set. Without your basically just guessing. It without live data and reading it, it's difficult.
Did your tuner actually hook it up and take it for a spin??? Or did he just download a pre-set map and say your fine?
Did your tuner actually hook it up and take it for a spin??? Or did he just download a pre-set map and say your fine?
#17
TECH Apprentice
iTrader: (1)
Join Date: Jan 2010
Location: Arlington, TX
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
On C5's there is 1 ground on the frame pretty close to the head lights on each side. There is also at least 1 ground to the block on the drivers side of the block under the head. There might be one on the passenger side also but I am not sure and this is for c5's
#19
TECH Senior Member
iTrader: (71)
One ground on alternator that goes to frame. iirc two on frame rail by fuses under ps.. one behind pass light. three on back of pass head.. One by battery and one that gets moved when you do wire mod.
i have some of mine moved around though in order to clean the bay up. But Im pretty sure if you have those accounted for you are good.
i have some of mine moved around though in order to clean the bay up. But Im pretty sure if you have those accounted for you are good.