Looking for some help. Running into problems after my 4L80E swap however having a hard time believing its related.
After the plastic accumulator piston on the 60e doing what it does best, cracking, and having the trans gone through. I immediately pulled it and swapped in an 80e I picked up from another forum member. Swap was straight forward besides the crazy tci flexplate I needed for the PI multidisc converter I used. Wiring was done via a tuned by frost harness, removed the iss codes, shortened drive shaft, reworked the pacesetter y pipe and removed the cats, and I was off and running.

So onto the problem… Noticed after a few days of driving that when in the throttle and above 3psi or so the engine power dropping off and exhaust not changing. After dorking around and swapping plugs to TR6’s and some NIB Taylor wires I had laying around I noticed when this occurred bank 1 was going lean when this occurred via the wideband. So out came the V2 and recorded some logs showing both the wideband and 02 going lean when this happens. I attempted to add fuel but no dice. Checked fuel pressure and it seemd good, 60 or so when cold then 48 or so when warm, didn’t see it drop off when in boost. I’ve also swapped 02 sensors and injectors bank to bank and the problem still resides on bank 1. Logged for misfires and didn’t see any when loaded only misfire were recorded at idle. Guessing next step is to swap coils bank to bank then tighten plug gap (shrug) when it stops raining. I’m really running out of ideas and could use some guidance. Any thoughts would be greatly appreciated.

-Shupe

 

are you running close loop or open loop, 2bar or maf? mine started doing some weird stuff like this when in close loop. the o2's were fighting with each other and one bank was going lean. went to open loop and its been good ever since.

 

Closed loop, stock map and maf. How high does the stock map usually read before being maxed, I noticed while logging it maxed out at 103.

Any idea why your started acting up?

 

stock map cannot read boost. 105kpa is max.

the left bank snesor reads the left bank. the right bank snesor reads both banks. the computer will try to fix what it thinks it sees on the sensors and will cause it to confuse itself.

 

Is that due to how the drivers bank exhaust is routed with the crossover pipe to the turbo?

 

Tightened the gap .030 on the drivers side bank thinking i'm possibly getting an incomplete burn due to too much gap but no luck same deal. Then tried swapping coils from bank to bank nope, not that either.

I've attached Log_0016 from this morning that shows the mv drop and the wideband go lean on bank1 while bank 2 mv remains well into the 900's. I added misfire current on 1,3,5,7 which didn't report during that time.

Any ideas anyone?

 

yes, the way the cross over pipe and all is set up it causes weird ****. log and force it into open loop and see what happens.

 

Forced it into open loop map only using swingtans vve tutural and sure enough it runs out smooth and sputterless.
Turbhoe what do you think the next step should be? So setting up in open loop map only disables maf and 02's and the associated correction they provide? What would have changed to have caused it to really onwork this way?
Wish the vve tables had been adjusted to where I'm at now mod wise seems like that would be a fine solution.

 

no matter how close your ve table is there will always be small corrections. mine was spot on per the wide band. but due to the way the o2's are setup it still tried to do corrections and screwed it all up in closed loop. when i go twins i will be running close loop again.
if you can go 2bar open loop map thats what i'd do. i stopped trying to do maf turbo stuff years ago.
you may beable to do open loop maf but i'm not real sure.