Afm failure cylinder 6

[Justin Yeager]

Just a few pics of the damage. 2007 Tahoe flex fuel 5.3.

Swapped with DOD delete kit from ams racing. Still having p0101 p0106 and p0068 codes that were not present before cam swap. Only thing I can think is the valves carboned up. I've replaced all the sensors with ac delco and it doesn't change a thing. The new and old parts show the same results on live data so im thinking head gasket leaking or valves leaking. I've put 6500 miles on the truck since, just clear the codes and roll. Spark plugs look fine. Oil is clean at every change, changed early to ensure it's always clean. Anyone ever exclusive these problems.

 

[Justin Yeager]

More pics

 

[swathdiver]

What new camshaft did you use and was the engine tuned for the new camshaft?

 

[Justin Yeager]

 

[Justin Yeager]

That's the kit I purchased, they said it's the same cam without DOD. They also tuned the computer. I've contacted them several times and they say I have intake leak. Can't b, I replaced intake gaskets twice after swap not them, sprayed all over entire engine with starting fluid with no fuel frim change. My mechanic says it's in the tune. Ams says they have done several tunes with no problems. The codes suggest more air coming in than its reading. I'm stumped, ams says they will look at tune for free but that's more down time which I can't afford right now. Was hoping someone in my area would use hp tuners and look at the tune. I would pay lol. Btw the truck pulls harder than ever and runs great.

 

[swathdiver]

Ok, so you are able to see long term fuel trims and they are what at idle? Do you have the cam specs by chance, every camshaft should come with a cam card so you can verify specs and make sure it gets installed correctly so the timing is not off.

I don't know of a single pattern camshaft made for VVT that was used in any LS engine. Hmm...

 

[Justin Yeager]

My messages with ams racing

 

[Justin Yeager]

Long term fuel trims are bank 1 0 bank 2 +2% short term fuel trims fluctuate but never above +5% or below -5%. My 07 does not use vvt

 

[swathdiver]

Long term fuel trims are bank 1 0 bank 2 +2% short term fuel trims fluctuate but never above +5% or below -5%. My 07 does not use vvt

With trims like that you do not have intake leak problems. That cam is probably from the LH9, slightly smaller grind than ours and had VVT.

Anyhow, with those two codes, P0101 and P0106, they suggest a leak (un metered air) between the MAF and intake manifold. Not the intake to heads. I'd look for cracks, misrouted hoses and the plenum hose from the airbox to the throttle body.

 

[Justin Yeager]

I've swapped intake tube with maf from 07 suburban no change. Best friend drives burb 220000 miles and afm just failed on his. Cylinder 1 for him but same crap. Ate the cam. Been over intake checking every seam and factory plugs nothing seemed wrong. And i spayed staying fluid and I mean I soaked entire intake. No change in trims or idle. I've ruled out leak in intake tube and intake. Tried propane even to Get under intake thinking it was there. I've swapped everything I can think of from his with no change. Might just throw his intake on and see what happens

 

[Justin Yeager]

Would it show different code if valves weren't seating correctly? Maybe head gasket leak sucking in air? I was hoping it would clear up after fuel treatment with every tank but same problem still there. If I drive under 60 and like a grandma codes will not show up

 

[Kraig]

Anyone think a TPS relearn would help synchronize the TPS, MAP, and MAF correlation?
OP; have you looked at TPS position with it running/driving?

 

[Kraig]

After thinking more about this, I don’t think you have carboned valves or a leaky head gasket—you’d be pushing air out or drinking coolant, not getting a vacuum leak.
Have you watched MAF or MAP values while driving under the conditions that trip the codes. I’m kinda wondering if maybe hammer time causes you to lose a ground that affects all three sensors.

 

[Justin Yeager]

I actually replaced tps over the weekend and did relearn without scan tool. Idles fine till p0106 shows up. I have service brakes soon after cam swap as well. Pads are brand new. Maybe not making enough vacuum? Wish I had a better scanner, just don't have the funds for a nice unit. I have toque pro with cheap bluetooth adapter. It has new cam sensor that was changed when swap was done

 

[swathdiver]

I've swapped intake tube with maf from 07 suburban no change. Best friend drives burb 220000 miles and afm just failed on his. Cylinder 1 for him but same crap. Ate the cam. Been over intake checking every seam and factory plugs nothing seemed wrong. And i spayed staying fluid and I mean I soaked entire intake. No change in trims or idle. I've ruled out leak in intake tube and intake. Tried propane even to Get under intake thinking it was there. I've swapped everything I can think of from his with no change. Might just throw his intake on and see what happens

I actually replaced tps over the weekend and did relearn without scan tool. Idles fine till p0106 shows up. I have service brakes soon after cam swap as well. Pads are brand new. Maybe not making enough vacuum? Wish I had a better scanner, just don't have the funds for a nice unit. I have toque pro with cheap bluetooth adapter. It has new cam sensor that was changed when swap was done

I think you're doing everything right to eliminate each possibility Justin. As for vacuum, the ECM takes a reading from different places in different scales. If the Torque Pro can read the Brake Control Module, it should pick up inches of vacuum off the booster.

You might want to post over at Performance Trucks forum.

@01ssreda4 @Scottydoggs @soulsea @67RS427 @SnowDrifter @Galante @kbuskill @OneofFew @gpracer1 @randeez

 

[SnowDrifter]

You mentioned you had a different tune on there for the afm delete

What happens if you you put the stock one back? Map/maf codes come back?

 

[Justin Yeager]

Had ams racing tune the computer. Can I change it without hp tuners?

 

[Kraig]

A stock tune is going to include AFM and throw different codes—it needs a custom tune with this cam in mind. It may or may not be the tune, but I doubt it’s a vacuum leak like they’re saying.

 

[PG01]

The tune they loaded better of had afm delete in it since they sold him an afm delete kit..... but ya never know.

I don’t think you have vacuum leaks/ problems i think you have a bent pin or connector or wire shorting on exhaust or pinched somewhere and when you get on it it moves or grounds throwing your code, that is, if you are really stomping on it. Maybe your motor mount is bad and the motor lifts just enough to pull on one of your connectors that you plugged back in....

 

[SnowDrifter]

A stock tune is going to include AFM and throw different codes—it needs a custom tune with this cam in mind. It may or may not be the tune, but I doubt it’s a vacuum leak like they’re saying.

Indeed. But my thoughts were this:

Chasing down wiring can be a time consuming process. If OP has the means of quickly applying the stock tune, we can determine if it's an issue with the tune or something else and start looking from there.