Robotech

Doc, yes you may and I have a futon with your name on it (and if it's not on it I have a can of spray paint to fix that...)

fivepoint, that may, in a way, be the problem but in a backwards kind of sense. See, his Manifold Air Pressure (MAP) sensor is reading just a bit of vacuum under WOT...about 97 KPh. 100 is static air pressure (whatever the barometer says current pressure is on startup). However, his stand alone boost gauge is reading 13 lbs of boost which translate into a MAP reading of about 180 KPh or so. This means the MAP sensor is not seeing the right amount of air pressure going into the car.

Now, I'm not sure what the ECM in the Cobalt SS/SC or Ion RLs does with the MAP reading in accordance to fueling but if it affects fueling at all then the ECM is seeing a heck of a lot less air than what is really being pushed into the engine which, of course, would mean it wouldn't send in as much fuel as it should and thus lead to a huge lean condition. O2s back this up that at 3K they go EXTREMELY lean even for a narrow band O2. Usually double digits. The plummet from around the 900 range down to like 18! however, it is hard to say if this is something then ECM is doing to protect the engine or if it is because of the faulty MAP reading and it's just running lean.

I think I'll have Shaun do a run tonight and have him watch the mechanical boost gauge to see what it does when he hits 3K. If it stays constant at 13 lbs as the engine falters it's going to make me wonder. Actually, maybe I'll design a second MAP device to run into his HPT unit in the analog digital mode and see if it can collaborate what the on board MAP is seeing. Yea...that will work.

Shaun, time to hit up E-bay for a 3-bar GM MAP sensor and pigtail like the one I have on the GP.

fivepointohman

I see what your saying, here is my question, So before 3k rpm and after 3k rpm the car runs strong or is it after 3k that it runs like crap? My basis is on if its just at exactly 3k rpm then i would push towards a PC glitch. I definetly am watching this post carfully.

06blackg85ss

iTrader: (1)

yeah but at 3k is when it would starting making good boost. I hope it's not PCM related, but also there was no 04 cobalt ss/sc only started in 05. Damn rl's lol. But I still think it's a pinched harness somewhere on the MAP leads. either that or the PCM is done and won't fuel. That going lean is because the PCM isn't seeing the boost so isn't adding the fuel needed. I hope you get it figured out man, or you lived a bit closer to me. I'd def take a look at it if ya did

fivepointohman

I see what your saying, But i think he stated that the car will fun strong after 3K too right?

Robotech

Well, now the car is really going fubar. Now it's going pig rich! So much so it's killing the engine. It's missing at idle and if you rev it up then let it come back to idle the engine just floods out.

This one has me stumped. Shaun pulled plugs last night to confirm and they were wet.

I did check the harness and it looked like it was getting the proper readings. Only question, on these cars do the ground lines coming out of the ECM for the sensors remain grounded when the car is off? I'm assuming so and it would make sense but I would like verification. With the car off the only wire that was grounded was the ground wire. The IAT2 signal wire, 5V power wire, and MAP signal wire were not grounded out. (Used a volt meter to trace for shorts.)

But now this flooding issue is really driving us nucking futs.

fivepointohman

Well with this being said, You checked your TPS correct? That is in range? Also, what about ignition, cause if the plugs are wet, then you have some sort of issue with spark and or ECM firing the injectors. something is definetly wrong. If the MAP is way off too, then it would think your at WOT all the time and dump serious fuel obviously if it sees no vacuum. What about the cam sensor and what not, firing plugs at the wrong time. DO you have another ECM you guys can try just for giggles?

Doc

interesting....I know that the wires coming from the fuse box get chaffed sometimes, check the bottom of the fuse box, passenger side right in the middle. There is a bundle of wires that comes out at an awkward angle and can get rubbed wrong.

rukkee

iTrader: (3)

This might be stupid but it almost sounds like a crankshaft position sensor .

Psykostevo

When DOC is done, it may have more than his name on it!

fivepointohman

I agree with the crank sensor could be an issue. I would check all those sensors and there adjustments. Sounds to me like maybe your off timing and its not firing your injectors and spark at the correct time.

Robotech

ROFLOL...Okay, I only laugh because of the possibility of it being the CPS. The BIGGEST PITA of a problem I had with my Grand Prix...and it took a year to figure it out...was the CPS going bad. I had just shared this story with Shaun the other day too. LOL

We may have to swap that out. Do you need to pull the crank pulley to get to it? Will check the wiring too. It is getting spark because once it dries out it will fire and run. When it starts it runs smooth but then it gets rougher and rougher as it starts flooding.

We have another ECM we can borrow so long as we can get through the pass key stuff.

fivepointohman

Ok this is good, looks like your stepping in the right direction.

shaunmcdee

Whelp, the car is back down to stock now, Im going to try to take it into saturn and see if they will honor my extended warranty, looks stock as can be except a dual pass endplate, lol. But as soon as i have any word on whats wrong with the car i will let you all know.
I owe you all a great thanks for putting up with me and my crying about my car, lol
Paul, Frank, Dan, get my utmost respect for sticking with it till the end. Ill keep you all posted, wish me luck!

06blackg85ss

iTrader: (1)

no prob man, good luck and def let us know what was wrong

Doc

hows it run now that its back to stock..?

Robotech

This is ShaunMcdee and Frank the car still runs like poo, the car struggles and floods out while idleing.

Doc

there goes that theory

Robotech

Well, found the problem. Dieing ECM. Was covered under the emmissions warranty and replaced by the dealer. Car runs fine now. May have gotten water in the ECM at some point in time and that would have been what caused the problem. Now the re-mod begins. Wish we would have been able to get the borrowed ECM to work...we would have known this sooner.

Now to convince Shaun to get himself a second ECM just in case that this happens again.

Doc

thanks for the update.

shaunmcdee

Ya man, no problem.
Ran the car for a good hour, works well.
let it relearn the fuel trims, feels slow for bieng stock, lol.
tommorow is the big night for me to put back on my blower and injectors (im borrowing my buddies, hes stock)
then a retune. I think i want to learn how to make my own, and not just modify other ppls tunes. I mean im grateful for all the ppl whos shared them with me (Frank this is huge for you) but i wanna stop relying on others and just know my car, so things like this dont happen again. Maybe il write a thread on it, or ill Pm some of you tuner guys to get me started.
Anyways, heres the sum of the story.
Car started to run terrible. After 2 weeks of solid troubleshooting, we take it to Saturn of Riverside (great dealership btw) they have it figured out, diagnosed and back to me in less than 24 hours.
the cause was a fried ecm
the solution: a brand spanking new one, free of charge to boot. Hopefuly hptuners supports it, lol.
Again thanks to everyone that helped me out with this, your help is greatly appreciated!

Robotech

In my defense I believe I mentioned to you that it could be the ECM going bad...we just didn't have a spare to check it out. HINT HINT HINT

Which reminds me, I need to get my spare one back from the folks up in LV that borrowed it.

shaunmcdee

You Mentioned Nothing of the Sort!!!!!
Silence, for my foot find your backside!

fivepointohman

I believe I mentioned the ECM theory... LOL... glad all is working out now.. Why can't America stick with the basics of Fuel and Vacuum, Old carburator days??? Yes, I am 26 and know how to build up a carb...

Robotech

Only problem is that was a couple days after we had tried to swap them which was also a couple days after I mentioned he may want to try and swap it with a different one. LOL

And yes, I did mention to try to swap the ECMs...IIRC

"Hey Shaun, do you have a spare ECM you could swap in for this one to rule that out?"

"No, why would it be the ECM?"

"Sometimes they can go bad when you start reflashing them. Why do you think I have a spare sitting around?"

So...Boot to the head for you.