Lean at Part Throttle all of a sudden.. Changed Nothing.

I wired up my DVD player the other night, which is pretty close to where I have my Wideband grounded..

I drove the car the next morning, and at part throttle acceleration my wideband is showing around 16:1, which I normally read in the 14's at part throttle.. Full throttle is still about the same...

I changed NOTHING on the car for it to go from normal to this lean condition.. So I did pull a plug just to see if my wideband was lying to me... The plugs did look pretty lean..

So, I changed the fuel filter, even thought I'm sure thats not it.. Both pumps are still running....

Tomorrow I'm going to clean the MAF and air filter...
And last, I'm going to recalibrate and reground the Wideband, just to make sure thats not the problem all along...

If I'm only running lean at part throttle, I assume that can only have to do with MAF, or computer, because I have enough fuel the rest of the time..

Car is tuned with a Vortech FMU and MSD BTM for now...




Any other suggestions???



Grady????

Yes, the egr is still hooked up, but blocked off to the header..


The DVD player is not in there at the moment, just the plugs are wired up.. But, I know how picky the LC-1 is supposed to be about grounds.



What to you think about that spark plug?

Adam95GT said:

Id say that spark plug does look a bit on the lean side...

Click to expand...

Thats the only reason that I'm believing the wideband, and didn't just instantly recalibrate it... (recalibrating it is kind of a pain in the ass)

The plugs have always looked somewhat like that, but a hair richer.. I wish I could find the old pictures of them to compare.. I'm going to go clean the MAF right now.

Its just so weird, cause it seems like it dropped about 2 points all the way across the board, EXCEPT WOT.. Its idling right at 14.5:1 right now, part throttle cruise is at 14:1, part throttle acceleration is at 16:1, and WOT is still right at 12.0:1...

I haven't driven it yet, but I did clean the maf and recalibrate the wideband.. I noticed I had left the calibration wire stripped before and I must have accidentally grounded it when I was installing the DVD, which put it into calibration mode when the o2 sensor was still in the exhaust pipe, throwing off the readings...

I did start it and it is richer in part throttle blurps and throughout the rev range..

Apparently... It hasn't blown up yet, and they've pretty much always looked like that...

I recalibrated the wideband and that seems to have fixed my issue.. I know I must have grounded the calibration wire when the ignition was on when I was installing the DVD player, causing the 02 sensor to calibrate itself when it was still in the exhaust pipe, which is a no-no..

All is good now...