Navy David SS

iTrader: (13)

3 weeks ago finally went 11 - actually 11.73 . Car ran like a champ - I am using a 100 shot on a TNT wet system. Ran out of 104, put some 93 just to keep the car running the next day, but made no runs. Noticed the car was 'stumbling' a little. Put on the A-tap. Showed perfect on passenger's side, but very lean on the driver's side. Ltrm: B1S1 +25; B2S1 .08. Only an occasional misfire on passenger side. 'Burn' some of my old 02's seemed to be ok. Next weekend ran a couple more 11.7 & 11.8. On the last qualifing run the car leaned out again on the driver's side. Turned off the nitrious and just ran on the engine. Seemed slower, but still OK. Got my *** beat

Autotapped it again at home the next day. Same: perfect Ltrim on the passenger side from -1.8 to .08; lean on the driver's side +25. Didn't get a WOT run on Atap. Idles perfect at about 800 +/- rpms.

I have tried to track the lean condition down. I have done the following:

Changed oil
Changed plugs (TR-6 gapped to .040)
Put in brand new O2's - both sides
Changed fuel filter
Got rid of the A.I.R and EGR systems
Changed PCV
Brand new MAF (SLP 85MM - I have been running this 2 years
Ensured valve cover vacuum hoses are hooked up
Ensured the MAFT is working properly
Lid is sealed
No leaks from lid thru tottle body

Same thing

What is going on? Any suggestions?

Couple of questions. Could one of the injectors being fouling out? Is it possible that a valve spring broke? On a 98, how many vacuum lines should I being looking for (some say 2, some say 3 lines??) ??

I am only getting an occasional misfire on the passenger's side, if I richen up the MAFT to much. No misfires on driver's side.

Someone help -- please.

David

98TAauto

iTrader: (2)

id say it was a 02 on that side gone bad. Did you log your 02's and see how they are reading?

my car stumbled badly cause when the 02 goes the car dumps fuel on that side cause it has no clue whats going on. My stumbling was in the low rpms though.

Navy David SS

iTrader: (13)

Thanks for the reply.

Yep. Brand new O2's. Ltrims are the tell-tale idles. As said pass perfect; driver side way lean. Iwish it was just a burn wire,but I can't see any problems there.

JWRENCH

If it's only on one side you can pretty much rule out stuff like the maf and intake tubing etc. which is shared by both sides.

I'd probably check the plugs to see if one looked different than the others first to maybe narrow it down to one cylinder.

Could even be a bad intake gasket sucking air into the cylinder. Maybe hook up a vacuum gauge and see if it bounces around alot. Just my thoughts.

BTW, You're sure your bank 1 02 isn't stuck at .450 right?

Vettepartz

Try swapping O2 sensors and see if the problem moves. Then try sensor wires, etc.

TaTommyWS6

Did you check for any header leak? Header gasket, collector? I know if any outside air gets in the exhaust before or near the first O2 it throws off the signal... Just a suggestion.

Good luck, when you get it sorted out please tell!

Tommy

Navy David SS

iTrader: (13)

Thanks for the replies and suggestions. Everthing is welcome. The O2's are brand new. I'll check the headers. Exhaust - what exhaust - I have a custom dual that is only about 2 foot long, including about 12" billet muffler .

I have decided to take it to the local dealership and have them put it on their super-duper computer. Compression check may tell the story.

Thanks again

David

Viper

iTrader: (6)

It's been known to happen that new O2 sensors out of the box can be bad.

Navy David SS

iTrader: (13)

Just got car back from dealership. Compression fine, fuel injectors good. They found a small vacuum leak - guess where ? The intake. 3 of the bolts holding the intake on had worked their way loose - stupid. But the SS is alive. Running better than ever

Thanks to those that helped.

David

JWRENCH

Cool, Glad your back in the 11's. I figured that intake was sucking air someplace.