Stuff's broke!

[eboggs_jkvl]

OK, I need eyes on this scan. THE TURBO CAR IS SICK. I'm up in Cincinnati and we're working on the car. Something is sick and I'm thinking the ECM has taken a dump. My O2 sensors aren't switching and the car won't idle. The car is running pig, burn your eyes rich. It won't idle without help.

Any thoughts?

Elmer

[swingtan]

Looks like you have bad O2 sensors or have damaged the wiring. There is no measured O2 voltage at all, which makes me think they are completely dead, to go with that your LTFT's are high with bank 1 pegged at +25% and bank 2 at +10%, so will be adding a bunch of fuel to the engine. This has probably occurred as the O2's were going bad and giving false data to the PCM.

To get it "somewhat" going, you could try a PCM reset to clear the LTFT learned data ( or reset the learned data via DVT's in ScanTool ). This should clear out the LTFT's and get you going to some degree. Then it's a case of looking at why the O2's are dead.

Simon

[eboggs_jkvl]

I should have given more info. The intake had a "plate" that lost a couple of screws and came loose and then the gasket blew out. This caused a vacuum leak. This came on gradually and had contaminated the LTFT table with some seriously bad data. My son fixed that leak but then the intake manifold still had a leak from the head gasket area. He ordered a 2nd set of gaskets and loaded them in and finally had a good seal. The garbage in the LTFT table was so bad it really plugged up the ECM from letting the car function as it was screaming lean and pouring gas in to fix it. The DVT function you mentioned allowed me to flush the table and the ECM quit having a hissy fit over the "lean" condition. I think the car is back to it's old rumbling self now as we took a 20 minute drive and got the LTFTs to fill in some good data and the O2 sensors woke up and did their "thing". The attached table shows how good we did! We are gong to check the torque of the intake manifold in the AM after it cools to make sure we've maintained the bolt torque. If that shows to be in good ordr, we will hit the road again and check the boost mode and see if this beast is ready to play with the big cars!

Thanks for the idea on purging that crappy data in the LTFT table. I think we are ready to drive and get that two bar MAP set up. We've installed the 2bar MAP sensor and have the 1bar spliced in until we get to the tuner. If I knew how to set up a 2bar MAP table I would add that myself and let the tuner do the SD tune.

Thanks again,


Elmer

[swingtan]

That would explain a lot. If the PCM looses the ability to adjust the trims ( just can't add/subtract enough fuel ) it'll figure something is very wrong and it should fail the O2's, hence there was no O2 data in the log. It looks like you could do with a bit od work on the VE table though as the trims are still a bit erratic when cruising. Also, your ECT seems a little hi, do you run a "hotter" thermostat or does the cooling system need looking at?

Simon

[eboggs_jkvl]

It as a stock t-stat so the ECT will be stock. The turbos do not need a cold t-stat as they only run under boost and the rest of the time it is a stock engine. My son is planning on getting an SD tune this week and the fuel trims should be better. I can pull the LTFTs down to a better number but I'd be wasting my time as he will be running a 2bar MAP and an SD tune.

Elmer

[joecar]

Good job...:cheers:

[eboggs_jkvl]

My son's car has been down since December. A little back surgery on the "aging" child and the intake sat on the bench for quite a while! When we were test driving yesterday, he had a grin on his face that makes everyone around him smile. We have to get the idle checked to make sure we have the set screw in the right place for cold starts. As usual, you only get 1 chance a day for a cold start when it's summer and in the 90s.

Thanks again for the help.

Elmer