Too much alky!

[bishir]

For a few daysnow I've been working on and cussing my car. I thought it was a coil pack.. I thought it was hoses popping off... and I even though it was vacuum leaks. The car was popping at high RPMS and sometimes blowing off a wastegate hose.

Well, the problem was too much alcohol. I turned the pump speed down and I was set. Moral of the story? Next time your car is popping and everything looks good on the scanmaster, check the alcohol!

James

 

[Kevin Turch]

I know that feeling all too well, same thing happined to me a few months back

Glad u got it fixed.

 

[Razor]

Too little is as bad as too much..need just the rite amount..

O2's usually will show when its way rich..

 

[bishir]

That's the thing... O2s aren't rich. They are low 700s... That seems to be what my car likes. Anything higher is pop city on alky...

James

 

[Razor]

Sounds like bad O2 or chip issue..low 700's is way too lean typically....High 700's are more typical..750-760's is usually optimal.

EGT's will show a lying O2''they do everytime..Target 1600-1625

 

[bishir]

Yeah, I thought that was too lean, but the car runs fine there w/o excessive knock. Perhaps I replace the O2 sometime. I don't think it's a chip issue but I'll try a swap.

Also, could a bad 02 or one that is going bad cause an off idle stumble?


Thanks,

James

 

[Razor]

yes becuase your ecm is constantly making fueling adjustments based on readings from your O2..after the engine has warmed up.

try this..when the car is cold see how it runs in open loop..should run same or better when it reaches temp to go closed loop. If the stumble only happens in closed you have your answer..typically

Original GM or denso O2's..dont buy the Bosch.

Lastly..if there are any issues with the way the car is running, I would advise againt any high boost flogging... if it aint rite..dont beat on it..it will never fix the problem..

 

[bishir]

Thanks Razor,

I'll try the open loop vs. closed in the morning. My next question is could I get similar results from a cracked header or header leak? I still haven't sent you that chip you were going to read for me. I've got to get that in the mail soon....


Thanks,

James

 

[Razor]

Cracked header will skew your BLM's and ecm cal's..so yes it an cuase your motor to give you fits.

 

[Crazi]

My car tends to run leaner then most I have seen. I am right on at about high 600 to 750 O2's...

I posted a while back trying to figure out what the problem was and the response I got was if it isn't knocking, keep driving. I watch the O2 for anything lower then mid 600's and as long as its above that, its fine.

 

[bishir]

Got it fixed.. it was spark plugs..