Cobalts SS banner

1 - 20 of 113 Posts

·
Registered
Joined
·
1,111 Posts
Discussion Starter #1
so as a few of you know, i had some crazy problems with the ss. i thought i had fixed it, but it happened again.

when the car gets heat soaked, it starts backfiring and sputtering. it only runs correctly from 2-4k rpm, with vaccum only! every tech has looked at it, and have argued over who has to attempt to fix it. everyone says the car works fine and couldnt replicate the problem. so we had a vette in a few weeks back, that was there for months..... every tech, even GM reps came to check it out, everyone was stumpted. well our performance tech, angel, finally figured it out. it was due to defective/cheap wiring and connectors in the fuel system. when they get hot, they cannot carry sufficent current for the high gas demand of performance motors. we believe my car has the same issue. also, the stage kit has caused increased fuel consumption and boost, so anyone with the kit that experiences symptoms like this, tell me immediatly. this could end up as a possible issue for staged vehicles, but it might just be my car, so dont get scared lol. i am having it completely torn apart and looked at tomorrow, so i will let you all know :D
 

·
Registered
Joined
·
91 Posts
i might have had something like that happen. i have the stage 2, and injen cai. other day went to start the car, started fine and idled okay....after about 2 minutes trying to find a cd to play it starts to sputter. drops from 2000rpm to almost stall back to 2000. does that a few times so i try to give it a little gas and i get nothing....... same thing happen to you?? was last week when it almost got to about 98 outside.
 

·
Registered
Joined
·
1,111 Posts
Discussion Starter #3
YES! good lord i feel sorry for you man. i have had all the techs look at it AGAIN as of last night, nothing except every curse word and flying tools. then i had our head performance tech who no longer works for us come in to look at it, even he was perplexed. so, its in the shop until its fixed. also, there is no CELs, all circuits check out fine, and the problem only happens when im driving it!
 

·
Registered
Joined
·
91 Posts
happened to me again this afternoon, the temp reading on my dash read 102. this time when i tried giving it a little gas the car acted like i wasnt even pushing on the pedal?!?!?!?! if this is the same problem the vette guy had, cant we just replace those connectors??
 

·
Registered
Joined
·
1,111 Posts
Discussion Starter #5
it is much deeper than that. each time i take apart one section of the fuel system i find more issues. this time i was going to take my injector harness out to look it over. got in my car, started it, drove it to 7-11, then into the garage. turned it off, 30 seconds later went to releive the pressure in the fuel rail. NO PRESSURE! it should be near operating pressure! so that lead me to believe the check valve in the fuel pump is bad, which would also account for the other issues we are having. the check valve basically wont allow the fuel to flow backwards, back into the tank. otherwords, if your car is 50% duty on the injectors, using most of the pressure, the flow will be ok. but if u let off, the pressure suddenly changes, sending fuel backwards, causing the sputtering (fuel starvation) i am going to pull the tank monday, and i will tell you what i find.
 

·
Registered
Joined
·
293 Posts
Good God...that is friggin mess. All in all though. You guys are the GMPP guiney pig's right now, I'm sure you'll find out the caper eventually. At any rate I'm sorry to hear about it.
 

·
Registered
Joined
·
3,049 Posts
WOW! I am having my stage 1 installed on Monday.......makes me want to reconsider.....
 

·
Registered
Joined
·
1,111 Posts
Discussion Starter #8
dont worry about it, think i fixed it. had nothing to do with the staged kit. i ran the crap outa the car yesterday, and held boost on as much as possible. then got the car heat soaked, nothing happened. so i will keep u all updated if anything happens. however, make sure your installer for the stage kits is good, or you could end up like me
 

·
Registered
Joined
·
139 Posts
Hey John, so what was the problem if it wasn't related to the stage 2 kit?
 

·
Registered
Joined
·
3,049 Posts
soccer1061287 said:
Hey John, so what was the problem if it wasn't related to the stage 2 kit?

Or is it related to running the 2.8" instead of the 3.0"?

I am looking into putting on the 2.8", but I may not if after going with the 3.0"*I already have Stage 1*, Cat-back and then CAI. I might do the GMPP headers but I'm not into drone when on the highway or cruising.
 

·
Registered
Joined
·
3,049 Posts
Also are the injectors on the stage 1 5.64 gallon per second? I am looking at the build book from gmperformancedivision.com, I don't know where I'd be able to do all of that in the build nor could afford to.
 

·
Registered
Joined
·
284 Posts
This has happened to me twice in May. My car is in the shop right now. This is so aggravating.

First Time: May 10, 2006
To night the wife and I drove the Cobalt to the restaurant for dinner. The drive there was great, the car ran fine. After dinner we got in the car and it started up just fine as usual. So we head out, after being on the road for about a quarter of a mile we have to stop at a light. Everything seemed fine. The light turn green, I go to take off and the car stalls out. Start it back up, no problem, go to take off and it stalls. It did this three times. So, I start it up the fourth time and away we go. The car sputtering and jerking all the way home like it was misfiring. By the time we got home it sounded like a back fire. This is the first time I have had any problem like this with the car. I hope that it will fine in the morning after it set overnight. Has this happened to anyone else?

Second time: May 31, 2006
It did it again tonight on my way home from work. About 15 minutes after leaving the parking lot I had to stop at a red light. When the light turned green, I went to take off and it stalled. Restarted fine, it took around 3500 - 4000 RPM’S to get it to move and not stall out.

Then it started to sputter like it was missing. I checked the temp, it was 202 F. I had about a mile more to go to get home. Every time I stopped, it stalled out but would restart with no problem. The hotter it got the worst it got. By the time I got home the temp was 210 F and almost a like a constant back fine / miss and the supercharger would make a very loud whine and then back to normal.

I let the car set for an hour and a half and it stated up fine and no more sputtering. The temp was 168 F. I took it for a 10 mile drive and the temp never got above 189 F.

Maybe it has some thing to do with the temperature. I will be keeping an eye on the temp to see if they could be related.

Is this still happening to you?
 

·
Registered
Joined
·
15 Posts
do the vehicle go into limp mode? if so it is probably the drive by wire gas pedal cause my car would do the same thing with a 3.0 pulley. they replaced the gas pedal unit and now im running a 2.8 pulley with a stock computer and injectors and have not had one problem. pulley has been in for about 4 months.
 

·
Registered
Joined
·
3,223 Posts
sorry to hear about that, i know the fans come on at 210 but stay on till for a little while, maybe there is something wrong with the wiring to the fan? is it on the same wiring diag with the injectors or fuel pump????
 

·
Registered
Joined
·
91 Posts
this would be my third time. my car sits outside my office from 8am to about 530-6pm everyday in direct sunlight. avearge temp in fl right now is about 90. last week went to drop money off at the bank, all is fine until i pull out of the teller window, just like last time...i push the pedal and nothing. all i get is the rpms trying to recover every time the drop below 1k rpms. from 1k to 3k about 6 times. the only thing i have noticed is that when this does happen, i can turn the car off then restart it right after and all is well!?!?!?! do we know of ANYTHING that might be causing this?

Has this happened to anybody in colder weather????
 

·
Registered
Joined
·
284 Posts
Well I picked the car up from the dealer yesterday and they found nothing. I knew that they wouldn’t. But the reason I took it in was because I wanted to paint my rear calipers and I could not get two of the rear passenger lug nuts off. They replaced them and told me that they were striped out. Covered under warranty.
 
1 - 20 of 113 Posts
Top