jfox

took my 2005 cobalt ss to the chevy dealership the other day to have them put it in time after i replaced the head on it it has good compression and started up but was one tooth out of time , and now for some reason im not getting spark. i cant afford to have the chevy dealership fix this and im out of ideas , so far ive checked all the grounds replaced all 4 coils new pcm and reflash new plugs checked all the fuses , im clueless this is killing me i just want to drive my car, any ideas or suggestions would be very much so appreciated

brian.olsson

I"m in, having the same issue, someone's got some ideas on this, I know its gonna be something stupid and easy

Validater

iTrader: (1)

Just gonna throw this out there. Did ya check the fuses? Also bad ground maybe?

BankerBalt

i'm gonna guess ignition relay/fuse

brian.olsson

well, for me, I know its not fuses, relays, or grounds, somehow, something blew the curcuit board for the fuse box, so I replaced that, while I had it out, I pulled the entire engine harness and checked everything, no cuts, or anything crazy, all grounds are hookedup, all fuses are brand new, and I've tried the relays everywhere, what trips me out is I just put the engine in, got it started and it ran just fine when I still had it on jackstands, but I had a clutch line leaking, so I had to pull the tranny to fix that, put the tranny back in, and thats when I had the rest of the problems with the fuse box and it not starting, everything is hooked up as it should be, just no spark

BankerBalt

that's how my car was when i rebuilt the engine. put it back in, hooked everything up and no spark. i replaced the ignition relay and it started right up. if it's not getting spark and your harness is fine, maybe you have a bad ground on the battery or the block

brian.olsson

yeah, I've been messing with all the grounds, I've got power with the switch on to the coils, I need to test for power to my cam sensor, but I need another person to do that

Pepsi

iTrader: (3)

that is weird. Ive replaced two cobalt engines for customers and never had this problem

brian.olsson

yeah, only thing that i'm tossing around is somehow, ecu

bratboy90

iTrader: (7)

Try plugging in the coilpack harness....LOL That was my problem

Validater

iTrader: (1)

Just gonna put this out there. I know there are 2 ground cables that attached to my buddies G5 going through the trans bolt. It was the main ground then a small feed ground. If you forget that small ground. I guarantee it won't fire.

I remember working on a Duramax at work one day. I had it running to warm up the coolant to remove all air locks. I think I was in the process of replacing 1 of the 2 ground cables that were cut by the fire department (for the record they only isolated one of the batteries. so I wasn't harming anything removing that one batter cable that was already cut) well I didn't notice the stupid small ground ribbon cable attached to the same bolt as the ground. The motor choked, stuttered, and shook, Caught for a second as it got ground again, then straight died and wouldn't fire till I noticed what had happened. It turned every light on the dash on. except airbag. So yeah. 1 missing ground and you're gonna have problems.

brian.olsson

hmmm, I"m gonna have to check that, I mean I tested at the coil packs for power with the ignation switch on, and they have power. but maybe their not plugged in.


yeah I know about the grounds, their hooked up, but I do have the main ground and the harness ground in two different locations, I"m gonna change it tomorrow I hope and put them on the same spot, but I highly doubt its gonna work, since I had the engine running already the way it is now.

jfox

make sure to check your injector wires very carefully .... i had one pinched in the valve cover wont get spark if the injectors arnt firing

brian.olsson

Hmmm, didn't know that, I'm sure mine are firing, when I crank it over I can smell fuel, also I had it running on e already, and haven't touched anything around the injectors, all I did after I had it running was drop the fuel tank and swap to a aremotive stealth pump, and pull the check ball out, and dropp the tranny to fix a hydraulicleak

OneCOLDBIZL272

iTrader: (2)

Make sure your coil harness is plug into the coils .And that the maf harness isnt pluged into the injectors. for they are the same style plug and can be easily wrong. Also make sure the supercharger inlet and barometric sensor are correct. They share the same plug style.

This might not be the problem but worth looking at to make sure.

Maf and injector share same style plug. Car will not start.
And inlet pressure and barometric pressure share the same style plug harness.

brian.olsson

Checked them, and all good, I never unhooked them when I dropped the trans, and before I dropped the trans it ran perfect, I've got power to the coils, just not getting a signal for them to fire, I'm kinda leaning towards low fuel pressure since I pulled the check ball out when I swapped the pump, or no power to the cam sensor

OneCOLDBIZL272

iTrader: (2)

Have you tried reflashing the ecu. Make sure the ecu plugs are plugged in securely as well. Have you done the crank relearn? Also if you took the cam angle sensor off and back on did you have the hex at the right spot. If it's off one tooth car will not fire.

brian.olsson

Yes, I've tried different tunes, and I"ve checked the plugs plenty of times, I can't do a crank relearn atleast with hp tuners cause I can't run the car to get the coolant temp to 170 degress, and the cam sensor was my first problem trying to get it to fire the first time, but it would still try to fire even though it was off, but I realigned it, and it fired right off, and I haven't pulled it off since it fired, just swapped in a new sensor.

OneCOLDBIZL272

iTrader: (2)

Do you have good grounds. Specially on the ground strap coming from the head. Paint cleaned off all surfaces where grounds are? Guess check fuel pump. Make sure the fuse box and clips are all pluged in if you removed the fuse box at all or took it out of the bay.

OneCOLDBIZL272

iTrader: (2)

Throttle body on the right way? If it came off doesn't hurt to check to make sure the butterfly's not stuck shut.

OneCOLDBIZL272

iTrader: (2)

And this might be something to check. The crank sensor. And or the the cam angle sensor again. If you got it to start once than when you tried to start it again and arnt getting anything your off pos by a full 180* ive seen that happenthe car cranks and fired the initial time but never again. Your 110% it's correct thou.

brian.olsson

I ended up putting new crank and cam's sensors in, and I"ve checked and rechecked the wireharness, and fuse box, I've pulled the wire harness like three times just to check for cracked or broken wires, lol I"m pretty good at it now, lol

and the cam sensor I had 180 off the first time I tried starting it, and it still attempted to fire, did a little looking on here, relized that when I put the engine together the gm build book tells you a unclear way to set the cam sensor, so I went out, put the engine at tdc, pulled the housing, seen it was off, flipped it 180, stuck it back on, and bam, car fired right up like the engines been in their since 2006, since than, I"ve rerun vacuumns, dropped the tranny to fix a hydrulic leak, dropped the fuel tank to put a new fuel pump in and pull the check valve out of the sender, changed the fuse box cause somehow the circuit board fried, still have no clue how that happened, and that led me to pulling the wireharness a couple times to make sure their were no shorts, everythings all good.

Tomorrow, I"m gonna check to make sure I have enough fuel pressure at the rail, cause pulling that check ball drops your idle pressure to 42 or so its suspossed to and iirc anything less than that and it won't fire. and I'm gonna check the power to the cam sensor, all in all, buy the end of this week, its gonna be running, or tore back apart, lol

Will Strom

So some months ago i had my trans replaced. I got the car back and it started acting up, like the shop installed a two step on my car, died abput 30 minutes of having it and finally started up again. Ran good for like 4 days (made a nearly 1,000 mile trip with no issues) got back from the trip and the car started dying while decelerating and finally died and wouldn't start. Took it to a pro shop, where the replaced the crankshaft sensor and threw a new computer in it. They assured me all grounds and fuses are good (verified the fuses for myself) I don't really know where all the grounds are though. I can smell gas when i try to start it, but it just cranks never any start. The new ecu throws a code for "crankshaft position relearn" tried the old way and no codes come back. Hoping someones figured this out to help. Thanks for taking time to read and sugggestions are always welcome! Thanks again

cobaltssdude420

Sounds like you need to purchase HP tuners and contact a remote tuner. It's well worth the money. I've heard good things about SSKEV and mine is in Alberta which is good as well