shadow95

This is going to be a lengthy, but thorough post on my issues with my '06 supercharged L61. I recommend watching the videos first and then reading to prevent biases as to what it might be.
I appreciate any and all help.

Here are three videos demonstrating the issue.
https://youtu.be/aOUoiKvPmXE
https://youtu.be/r8BVt3Xllj8
https://youtu.be/DnTua6DKc68

The story/history:
Mostly unknown, it was an auction buy (final price $2k). Was moved around from dealer to dealer and I don't have contact with previous owners. I purchased it with a check engine light and the code it gave back was for a failed crankshaft position sensor. When driving it would seem to randomly misfire/sputter depending on throttle position and RPMs causing it to hesitate. To remedy this all I had to do was let off and reapply the throttle and it would catch on again. So I replaced the crankshaft sensor and got a crankshaft relearn. It seemed to help slightly, but the problem persisted. One night I was testing and pushing it. It would constantly make around 12 psi of boost. Then all of the sudden it lost all power. It was continuously misfiring and threw a check engine light. I nursed it home and got a scan the next morning. The number one cylinder was misfiring. Checked the plugs and they looked burnt. Asked my stepdad (old time mechanic) about it and he said it was because it is running rich, but he said that shouldn't cause it to misfire. I checked for a spark in the boots and number one was not sparking. So I got an ignition coil housing from the scrap yard and swapped it out. This fixed the constant misfire; however, I am not able to build and go into boost now. I did a compression test and all cylinders came back fine.

The problem
Revving the car in while neutral to high RPMs and normal nonaggressive driving the car runs just as it should. It is just when I put it into gear and it starts to build boost pressure the car stutters and will not put down power.

Possible reasons include:
My spark plugs are a bit burnt.
My #1 injector might have a small fuel leak (it always seems damp at the bottom of the injector).
My IC auxiliary water pump is broken (tapping on it turns it on, but it instantly fails).
It is running an unknown custom tune that might be outdated and cause all kinds of issues. (I'm not familiar with how tuning works yet)
I doubt this one, but it could be. I took off the header that was on the car and put a stock 2.2 manifold on it because someone cut the 4th cylinder's header for extra noise probably.

Known Mods:
Eaton M62 supercharger
LSJ intercooler
LSJ Intake & TB
LSJ Header?
Unknown 3' Muffler
K&N Typhoon intake
Upgraded fuel injectors?
Single din gauge pod w/ boost vac gauge
Unknown tune

jdbaugh1

iTrader: (1)

So are you actually building boost or not?

Fueling is probably way off because the car doesn't even have a wideband gauge so I don't know how they would have dialed it in. If you're not building boost your bypass solenoid could be malfunctioning but your car is still dumping excess fuel causing it to misfire.

If you aren't throwing codes other than misfire I would guess it is a fueling problem as long as your spark plugs and ignition coil module are fine.

royce777

iTrader: (29)

looks like it might be a badmab header

Foximus

iTrader: (13)

Thats a badmab header. fairly common for them to crack sadly.

shadow95

Thanks royce777 and Foximus for the info on the header. Do you know if getting it welded at a muffler shop will hold it back together or will it probably just crack again?

Quote:

Originally Posted by jdbaugh1

So are you actually building boost or not?

Fueling is probably way off because the car doesn't even have a wideband gauge so I don't know how they would have dialed it in. If you're not building boost your bypass solenoid could be malfunctioning but your car is still dumping excess fuel causing it to misfire.

If you aren't throwing codes other than misfire I would guess it is a fueling problem as long as your spark plugs and ignition coil module are fine.

I tested it again just to be sure. The car does actually go into boost and makes around 5-6 psi.
Here's the another video. The first part is in gear second part is neutral with WOT.

You Tube

I took off the bypass solenoid and tested it and it itself functions properly. I am going to check voltage on the solenoid wiring and put the old ignition control module on the new ignition coil housing to see if it changes tomorrow hopefully. The car actually hasn't thrown any codes since I changed the ignition coil housing I forget to mention this in the first post that the car also has terrible mpg. Had some code for cat converter, but I have no info on it anymore. It was getting anywhere from 5-10 mpg even without boost. I am thinking I should rule out spark plugs just to be sure. What plugs do you recommend for my current setup?

jdbaugh1

iTrader: (1)

In your pictures that is not the bypass solenoid. Pretty sure that is your Evap purge valve. 2.2 setups with superchargers don't use a bypass solenoid but they do use a bypass valve that is attached to the intake kneck of the supercharger. That is what you should check. The first part of your video made it look like it could almost be sticking open. But then your revs at the end looked normal so idk.

When you are cruising what is your boost gauge reading? If you are getting horrible mileage I would assume you are dumping too much fuel and need a tune adjustment. After you look at your bypass valve you really should get a wideband gauge so you can see where your fueling is at. Unfortunately you are an 06 so as far as I know Trifecta is your only option and they don't appear to be taking new customers for our year of Cobalt. You may be able to make a plea to them idk. Else all you can really do is revert to stock setup and stock tune or go crazy like Foximus and setup a standalone ECM.

shadow95

The bypass valve opens and closes as it should. It also holds suction so it should be good to go. I checked voltage and that is fine. As for boost readings while driving, I haven't taken it out in probably a month and a half, so I don't know.
I am going out town until Monday, so I will not be with the car until Tuesday for a test drive. I don't have access to a wideband gauge. But if I were to buy one at this point though I don't see a reason considering we can pretty much guarantee it is fueling related no one tunes '05-'06 cobalts anymore. And a standalone is probably way over my head.

At this point, I want to swap ICM when I get back to see if there is any change, then one last test drive (and maybe pull). After that, I only see making it stock again and getting a reflash. Then one day taking the supercharger and bolting it onto my daily '07 2.2.

jdbaugh1

iTrader: (1)

Yeah you are right the only thing a wideband would be good for is confirming that fueling is the problem. I probably have all the stock parts you need for cheap if you do go that route as I have an 06 supercharged Cobalt and kept all the old parts I took off. Let me know if you are interested.

shadow95

Success!!!

I finally figured it out after about 25 weeks since I bought her I finally figured out what was wrong. I'd tell you all the things I did to figured it out, but that would be a little boring.
So it took almost half a year of on and off trying to fix it, I tried so many things and asked so many people but when I figured it made me so mad I wanted to punch a baby seal.
I don't know why I did this but it worked. I took off my air filter and she ran like a champ. boosting to around 6psi. A simple air filter was the cause of all my grief.

She has a couple of small issues that I need to work out, but she is alive and purring.

jdbaugh1

iTrader: (1)

Unless your filter is all clogged up for some reason I would think the only thing you might change by doing that is the way the MAF reads. You should take a picture of your intake setup. Also look into getting a real tune. Canned tunes on these L61 SC builds are typically far from ideal.

shadow95

I cleaned the air filter, but that didn't work. I found a box in the car for a RU-5147, so I bought that and it works great until about 80-100% throttle then the sputters like before. I have a video of it I'll post tonight when I get off work. Another thing I found out is that the TMAP is not one from the LSJ manifold. I checked what its readings were on a tech-2 and it was reading around 60-65 kPa key on engine off, so I don't know whats up with that.

jdbaugh1

iTrader: (1)

I was looking through your pictures of the intake and i don't see a MAF anywhere. Do you have one installed? If so where is it?

As far as the TMAP I am not sure which one is right for your tune. I am running stock MAP sensor tapped into a different spot on the IM. I am pretty sure my tune is mostly based off of the MAF though. One time I took the intake assembly off to clean my filter (my intake was configured close to what you have here) and I clocked it a little differently going back and it threw off fueling completely. It was running super lean and sputtering. That is why I am so curious about your MAF sensor.

chevygirl2006

Where is your maf? Lol and post a picture of your engine bay. I want to check something.

chevygirl2006

And I'm almost positive that's not a K&n intake. Looks like a no name brand.

shadow95

MAF is there it is just on the back side of the filter. I've run the MAP unplugged and there is no change in performance if anything it is slightly better. When I had it on the scanner with the old filter at idle my a/f ratio was running perfect 14.7, but I wasn't allowed to give it a pull or rev it up while I was there. I have some MAF sensors that I picked up from the scrap yard that I could see if anything changes.
(video of engine bay)

You Tube

chevygirl2006

That intake needs to be replaced. Cheap intakes like that make our cars run bad sometimes. Maf sensors are sensitive. They require to be a certain distance from the filter and throttle body. My friends car would sputter like yours after she bought a no name. Put stock back on and it was fine. What are your plugs gapped at?

chevygirl2006

What are your codes?

shadow95

I'm running AcDelcos 41-103 stock gap at .043?. I put a new set in to see if anything changed a while back, but only improved throttle response. They got blacked over within a week or two probably from her running rich and backfiring like a boss. I probably should use different ones, but everyone has their own opinion on what's best for a supercharger.
Code wise I got P0128 (she doesn't get to operational temp fast enough) I also got P0420 blasin (she's got no cat). I haven't checked since the new filter's been on.
Another thing I was thinking is that I had to take the header off her because it had a crack in the 4th cylinder. Now I am just using a stock 2.2 exhaust mani.

chevygirl2006

You can't run stock gap plugs after it's boosted. You need a smaller gap. .032-.035. Stock lnf plugs also work.

jdbaugh1

iTrader: (1)

Like Chevy girl said the location and orientation of your MAF filter can really throw things off. It is even more likely with the MAF so close to the filter. Just changing your style of filter could throw it off. I know you probably don't want to do it but that thing needs a wideband gauge and you need to get your tune adjusted. That intake you have could probably work if the MAF settings were calibrated for it. Your spark plugs aren't quite right but until your fueling is corrected those aren't your problem. It won't matter how many parts you throw at it if your fueling is off because your ECU tune isn't dialed in.

shadow95

I've got some sad news, emailed Trifecta and they straight up said no, so tuning is out of the question unless this local shop nearby says yes. But I guess I'll bite the bullet now. What ones do you recommend? Even if my '06 doesn't work out I plan on someday swapping the kit over to my '07 for fun. So I want something that's worthwhile. Oh, and I really do appreciate you guys helping me out on this it really means a lot to me.

Crav3

iTrader: (1)

It sounds to me like an issue with your tune. And its unfortunate but trifecta are the only ones that tuned the 06 2.2 cobalt. Be better off putting it to stock and getting a newer 2.2 for the kit.

​​​​​​​trifecta didnt even want to re tune my brother 06 after he upgraded his supercharger after we had paid them for a tune. They said they only do LNF cobalts now. So he put his back to stock and gave up trying to make his cobalt fast haha

shadow95

That sucks I was really hoping they would help out, but they don't like our cobalt's enough I guess. I'm probably going to put it up for sale nearby and see if anyone's interested. If I get not takers I'll strip her down and part her out.
Anyways, I thank everyone for their help. You guys are awesome!