KAMS not matching

BirdofPrey97

Registered User
I am at the breaking point.

Last fall it was reading similar and I swapped it to a 95mm TB and a slot maf and it read 1.0 and 1.0. I pulled plugs to verify they weren't flooded and now it's back to .793 and 1.0. Swapped 02s and no change. Tapped the fuel rail and checked for an exhaust leak and none was found. The only thing I can think of is that the fuel rail isn't seating completely and or an injector isn't. I am going to try a different fuel rail and if that doesn't work the car is going to scrap. $15,000 on an engine and it won't idle I can't afford more time or money on it.
 

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If you try a different fuel rail, then at the same time move the injectors from one side to the other. Then if your KAMs-bias switch side you probably have a faulty injector.
 
I am at the breaking point.

Last fall it was reading similar and I swapped it to a 95mm TB and a slot maf and it read 1.0 and 1.0. I pulled plugs to verify they weren't flooded and now it's back to .793 and 1.0. Swapped 02s and no change. Tapped the fuel rail and checked for an exhaust leak and none was found. The only thing I can think of is that the fuel rail isn't seating completely and or an injector isn't. I am going to try a different fuel rail and if that doesn't work the car is going to scrap. $15,000 on an engine and it won't idle I can't afford more time or money on it.
You need to smoke test it to find an exhaust leak
 
Exhaust leaks can be tough to find. Whats your vacuum look like at idle? Thats the simple exanation for a variance in commanded air and fuel which is what kamrf is.
 
Bank 1 is lean and bank 2 is Rich. Are you positive she was in closed loop at idle before you made the changes? Most cars with a decent cam I tune for open loop at idle do to this problem.
 
Bank 1 is lean and bank 2 is Rich. Are you positive she was in closed loop at idle before you made the changes? Most cars with a decent cam I tune for open loop at idle do to this problem.

The car hadnt been run in over a week. The updated tune was loaded and then the KAMs cleared. I clear the KAMS at least 3 times up to 6 before starting the car. It is a new tune from Dave. I will try installing the old tune and see what the KAMs read.

New smoke machine has been ordered. The old one stopped working.
 
Just realized I was trying to help you on Facebook....this is a better place. :D

I would try re-seating the EEC plug and/or the QH connector, if there is the slightest chance they could be loose or not thoroughly cleaned. The O2 sensor reading that just completely drops out in your datalog is the closest you are to the root of the problem. Besides physical wiring problems or a problem with the EEC or QH, I'm not sure what else it could be, but it is definitely electrical. If it were any type of air/fuel problem, I highly, highly doubt that you'd get exactly a 0.013V HEGO (or whatever the # was) continuously for a good period of time.

I'm not sure what would happen if it was the heater circuit for the O2 sensor, but I would think it would at least give you a legit reading for a little bit still....my money is on the signal/return wiring. Either way, both circuits are physically routed to/from the same place.

You did say that you swapped O2 sensors and the problem remained on the passenger side right? (didn't follow the physical sensor?)
 
One other thing - the KAM's should not / will not normally match when the car is in closed loop and using the O2's to adjust the fuel mixture. You can't turn off the STFT's (short term fuel trims), which play into the KAM#'s...they are IGNORED during WOT though...which is why you'll sometimes have a car that drives okay, but WOT is poopy...the MAF curve is off, but the car can compensate for the error. At WOT, the MAF curve must be perfect if you want a perfect AFR.

Resetting the KAM's clears the LTFT (long term fuel trims)...which is as the name implies. ;)
 
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