Misfire cylinder 4 & 6 deactivation solenoid circuit

[dbaker730]

2007 tahoe 5.3
Currently falling into the dod rabbit hole. Continuous misfire and only pulling p3441 & p3425 for cylinders 4 and 6 deactivation solenoid control circut. Previous owner just told me he had it deleted. I can verify it has an after market valley cover but the oem dod cover is sitting beside the right valve cover still plugged in. He also had a range technology plugged into the obd port. When I unplug the dod solenoids the misfire gets worse. What im really wondering is if I get it tuned to have the dod disabled, shouldn't this just bypass the two dtc's?

 

[j91z28d1]

I would start with getting it turned off in the ecm and see how it goes. since it needs to be done anyways

beyond that, not all deletes are same. a cheaper Amazon/ebay kit can cause more problems than it fixes sometimes. without doing it yourself, you really don't know. but judging by the old cover plugged in and dongle still in. had to say what was used.

 

[Dustin Jackson]

I am pretty sure that that motor should run just fine with that DOD cover plugged in on the side there WITHOUT the range disabler plugged in. But it sounds like some of the AFM related electricals are damaged so I would proceed with getting a proper AFM delete tune with the expectation that there is probably something else going on as well.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

Before taking out the parts cannon, I recommend using a quality bi-directional scanner to see that is going on with your motor, if you have not already done so.

If not, I recommend that you get yourself a quality bi-directional scanner to add to your tool box. Then, you will be able to read ALL trouble codes, along with a brief explanation/pointer to the source of your issue. You can test many of the truck's electronic functions with the scanner, in order to determine the source of an issue. You will also be able to reset/delete trouble codes, after taking corrective action. You will literally save thousands of dollars in diagnostic and repair costs over the life of your truck, and you will most likely recoup the cost of the scanner within 1 year.

 

[rdezs]

The optics of that AFM delete speak volumes about the quality of workmanship..... Or rather the lack thereof.

Definitely get AFM turned off in the ECM and throw that VLOM in the trash.

From that point on you're diving into the unknown. Did the previous owner even change the camshaft/lifters? And the whole list of other items that you won't know without digging into it.

My instinct tells me the previous owner was having an AFM failure of some sort, probably an AFM solenoid. Slap on a flat valley cover, plug in an OBD2 dongle, leave the old VLOM hanging by the harness and sell it ASAP as a vehicle with a delete kit. Sorry, hated to say that, but that's what my gut tells me....

 

[solli5pack]

The optics of that AFM delete speak volumes about the quality of workmanship..... Or rather the lack thereof.

Definitely get AFM turned off in the ECM and throw that VLOM in the trash.

From that point on you're diving into the unknown. Did the previous owner even change the camshaft/lifters? And the whole list of other items that you won't know without digging into it.

My instinct tells me the previous owner was having an AFM failure of some sort, probably an AFM solenoid. Slap on a flat valley cover, plug in an OBD2 dongle, leave the old VLOM hanging by the harness and sell it ASAP as a vehicle with a delete kit. Sorry, hated to say that, but that's what my gut tells me....

+1 for this. Not only do you need to get a non AFM tune flashed onto the ECM but you also need to physically verify the AFM components have been removed. Maybe remove the valve cover and look for new head bolts or can you see the edge of the head gaskets and do they look new?

 

[rdezs]

I think anyone who has done a quality AFM delete with quality parts, and has the receipts for the new components.... Would offer you those right away to justify the selling price.

That concept that's been around for decades... Buyer beware.... Is more important now than it ever has been. There's a lot of vehicles out there in need of both the engine and transmission..... Selling for $10,000 or more, and in effect it is totaled as soon as you drive it off a lot.

 

[dbaker730]

I appreciate everyone's insight. I would like to point out that my tahoe has ran great for the past three months with no issues. I guess I should've mentioned that lol. The previous owner is somewhat of a family friend plus I was able to buy this from him for $500. So I wasn't to concerned with any issues it did have. He sent me the link to the kit that he did buy but it was some off brand i haven't heard of. I live down the street from Michigan motorsports so I think I am just going to go to them, buy a new kit and have then tune it and see where we go.

 

[dbaker730]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

Before taking out the parts cannon, I recommend using a quality bi-directional scanner to see that is going on with your motor, if you have not already done so.

If not, I recommend that you get yourself a quality bi-directional scanner to add to your tool box. Then, you will be able to read ALL trouble codes, along with a brief explanation/pointer to the source of your issue. You can test many of the truck's electronic functions with the scanner, in order to determine the source of an issue. You will also be able to reset/delete trouble codes, after taking corrective action. You will literally save thousands of dollars in diagnostic and repair costs over the life of your truck, and you will most likely recoup the cost of the scanner within 1 year.

I have a decent scanner. I have other codes for random stuff like o2 sensor circut and and evap vent circut. These code have always been present and have never effected it.

Also here's the pics of the $500 beater

 

[solli5pack]

Can't go wrong for $500!

 

[solli5pack]

That ground strap in the picture looks a little suspect. You should test it to see if it's still providing a good ground. If it's bad that can cause all kinds of electrical gremlins to run about. And move the clamp on the brake booster hose over to the booster.

 

[rdezs]

Yeah, for $500 you got a deal. And right down the road from Michigan Motorsports? You are all set.

 

[Dustin Jackson]

That’s good to know it was running well until recently. It could be a simple fix. I’d inspect the ignition coil and grounds like mentioned earlier

 

[j91z28d1]

it's nice that he linked you to the kit he used, I was going to say there's a 99% chance it's got some kinda non afm lifter in it to be running with a flat vlom cover. if you put a flat cover on afm lifters, it blocks the oil ports and runs about 5mins before a afm lifter gets stuck. they basically have to be vented very well.


I have seen a bunch of threads about cheap non afm lifter being used, and failing. pretty much instantly and having to go back in. I don't blame anyways, you don't know till you know kinda thing. I have no idea if the cams and any good. I've heard people say the heat treating might be suspect on them too. but don't know.


that said, I think I'd still turn off in the tune and trouble shoot little deeper

 

[rdezs]

Hopefully it wasn't one of those bargain basement AFM delete kits from China?

 

[rdezs]

Going to be hard to troubleshoot until you get the AFM turned off in the ECM. If you're getting a code for one of the solenoids, that means the ECM is expecting to see AFM. And if it's doing that, trying to deactivate some cylinders, it shuts the fuel off to those cylinders.

 

[89Suburban]

2007 tahoe 5.3
I can verify it has an after market valley cover but the oem dod cover is sitting beside the right valve cover still plugged in.

WOW!

When you think you saw it all in this place, haha

 

[89Suburban]

I am also happy to see I am not the only 07 Hoe with a driver side wiper that refuses to sit level. It's either angled down, or up if you try to move it a spline higher...

 

[Joseph Garcia]

I am also happy to see I am not the only 07 Hoe with a driver side wiper that refuses to sit level. It's either angled down, or up if you try to move it a spline higher...

Very interesting. I don't think that mine has splines, but instead simply a tapered pressure lockdown using the nut. I just replaced a wiper blade, and I adjusted the wiper arm to sit on the black mark on the windshield indicating perfect positional alignment.

 

[dbaker730]

Sorry I haven't been logged on to respond to any one. Its road construction season here in michigan so I'm working non stop.

I would like to provide an update to the situation. Just got the ecu back from from getting tuned. Completely solved my issue woth the misfire but opened up another issue. Had a bad connection at the ecu when I first installed it so it would just crank, no start. Had my blood pressure up there lol. Reconnected the lower connector and it runs now just no tachometer and not getting and rpm reading on my scanner. Just shows 0 rpm at all times. Had a p0335 for ckp sensor circut and p0300. Can't get the dtc to duplicate. I think I may have a bad connection at the ecu still. Will update more tomorrow.

The ol'girl is going to be coming up for sale here shortly. Unless I can find a way to add a truck bed to it