ok guys. so my car was misfiring really badly a week or so ago and we traced the problem to my wastegate on my supercharger not opening and closing properly. it was stuck shut and we were able to force it open and this cured the problem for a little bit but now my car is misfiring again and im sure its the waste-gate this time too. has anyone else had this problem before? is there any advice that anyone can give me to fix this issue once and for all?

 

By "wastegate" do you mean the Boost by pass valve and actuator?


photo credit to jdbaugh1


My car had been in storage for a year, when I got it out my BPV was stuck in bypass for months, with no missfire, when I found out it was stuck I drove around with it bypassed untill the replacement arrived (ill advised, I know) still no missfire

If that's the part your talking about, I'd say something else is a miss

If its stuck open, you just won't build boost, if its stuck closed you'll build boost all the time.
We found mine was stuck when we put it on the dyno and it only had 133HP to the wheels.... bypassed the bypass and I hit 225whp

 

yes. this is what i am talking about. i believe mine was stuck shut though. so you think something else is causing my missfire? because once we got this open, the misfire went away.

 

All I can say for certain is that in my 06, I drove for months with is stuck open, and about 2 months with it stuck closed, and never once had a missfire.

While it was open I had this feeling like the car was gutless, but I just figured it was because I was away from the car for a year... I should of trusted my gut, might of found it sooner. Of course my non-functioning boost gauge was no help.

 

well i for sure have a misfire and this is what seemed to be the cause of the problem.

 

Try replacing it, GM #89018120, you'll need the SC gasket (GM#12584342) too because the whole SC has to come off

ZZP sells a kit that comes with all the hoses you need, I don't know if the GM one does or not, it was faster for me to get it from ZZP, my local dealer said it was weeks to get it. You'll have to buy the gasket on your own, not included in the kit.
Ecotec Parts EATON LSJ Bypass Valve

Good time to change the solenoid too, GM#1997244

When I got mine all apart the valve was sticky without the actuator attached. I dripped some 3in1 oil around the shaft and then worked it in by opening and closing the valve by hand a bunch of times. Before I started I had to use channel locks to move it, when I was done I could easily move it by hand.

 

i will def do it then. but you dont think that it is the problem of my misfire?

 

I have my doubts, like I said, I drove with it stuck in both positions and never got a missfire or even a CEL.

The only issue I had during that time was totally unrelated, I had my throttle body crap out on me.

 

Are you throwing a code for misfire? Or does it just feel like it's misfiring?

 

CEL flashing. only codes are for my thermostat and Coolant Temp Sensor ECT (which i am replacing now)

 

If the CEL is flashing for misfire it should set at least a random misfire. I'd start with replacing the Bpv and see if the replacement deals with the issue.

 

okie dokie. so a bad BPV can def cause a misfire then Ecaulk?

 

I'm saying you don't have a misfire issue. If the CEL flashes for a misfire it will store a misfire code, a flashing misfire is just an indication that something is way off and can cause serious damage to the emissions system. If the bpv is open then it would be dumping significant amounts of extra fuel which will damage your cat quickly.

Since you don't have a code for misfire, and once you freed the bpv it starting acting ok, replace the bpv and ECT and see if the issue goes away.

 

ok cool. that is where i will start then. thanks man.