brandenbmx

I had posted in a few other people's threads about afm/ dod issues on my Impala SS, and 06 Trailblazer. Both with 5.3's.

After talking to a bunch of people and reading posts on here and a GTO forum I finally decided to go ahead and do the trailblazer (actually my Bosses wife's car). We ordered the SDPC kit, w/ cam.

This Trailblazer fought the entire way, but it is done, minus the tune...
There is one problem, and a HUGE problem at that. This thing has absolutely no, none, not even a little bit of power. It starts and runs and idles smooth as glass. But when you drive it, pulling out into traffic is not even remotely an option. Once the RPM's are above 3k there is some throttle response, but low rpm there is nothing. The only codes it has is the open circuits for the cyl deactivation.

I know the timing is DEAD on because it starts and idles soooo smooth. Anyone have any suggestions?

The other posts I have read said that they had issues with idle because they didn't swap cam, but I did swap cam and I don't have idle issues. Most of the people I have talked to, including a gm mechanic from a local dealership all said that I shouldn't expect any running issues with the cam used other than the cel's for the cyl deactivation and it would run fine prior to getting tune to turn that off.

The GM numbers on the cam from SDPC is 12560967, with 415044 stamped on the cam. From what I found that cam is 99-05 4.8 and 5.3 truck cam.

Anyone know where I should start to DIAG this?

Scoggin Dickey

iTrader: (34)

DOD is still turned on in the tune? If so, there's a good chance that's your problem.

brandenbmx

Are you the infamous Jessy?!??

I would like to talk to you if possible... Could you pm me a contact number and a good time to call you? I have a few questions about the cam we got and tuning questions.

2XDropout

I know that this is an old post, but after far too many hours of searching on the internet this is the only thing I have found with the same issue I have. Did you manage to solve this problem?

I have verified everything I could think of that could be causing the problem: exhaust back-pressure, vacuum leak, timing, fuel pressure, spark, spark advance, several more things I can not think of at the moment. Everything has checked out to be functioning perfectly. I even ordered a new computer and had it flashed to the correct VIN number just in case. Nothing has fixed it, and it isn't even throwing a single engine code (I have a tuner hooked up so it doesn't throw the cylinder deactivation code). I tried running it both with and without the tuner just in case that was causing the issue, but it makes no difference.

I have talked to several of my local mechanics, including one from the Chevy dealership, and they all suggest the things I have already verified. I decided to re-verify my checks in case I had made a mistake, so I asked my father (a mechanic with 30+ years of experience) to help me. He confirmed my results that everything is working fine.

The 97 I've been driving for 10 years is on its last leg and I'm going to need this other one soon. I really hope you can help me out.

Scoggin Dickey

iTrader: (34)

When you say that you have the tuner plugged in, do you actually have DOD turned off in the tune? Did you replace the valley cover with one without the solenoids, or did you use the tower plugs?

2XDropout

The tuner I have is an automatic disabler; the kind that you just plug into the OBD2 connector and don't do anything else with it. And the valley cover was replaced with one without the solenoids.

forgedfivetree

I am in a similar situation. heads blew due to AFM so I rebuilt them with a BTR stage 2 truck kit. Pulled the motor, replaced cam bearings, honed cylinders, new rings, decked the heads, the whole 9. The truck had a bunch of issues with tuning afterward and my fuel is cranked so I don't shut off coming to a stop. any help?

2009 Silverado 1500 4WD

Full Power

.....
..... Remove the " Disabler "
..... Connect HPTuner interface.

Scoggin Dickey

iTrader: (34)

That's your problem. We recommend having a tuner properly disable AFM in the tune

2XDropout

Well I am extremely thankful to you guys. I bought an actual tuner that allowed me to disable the AFM in the computer and now the truck runs perfectly. Thanks a ton

Scoggin Dickey

iTrader: (34)

I'm very glad to hear it! There's nothing more frustrating than being lost in a problem that doesn't make sense.

Miketizzal

I took the old valley cover apart and hooked it back up so I can drive it to the dyno. It runs good just has some backfire here and there.like a shotgun