2008 LH6 AFM DOD delete, now no start

Hello fellowship of tuners.

Taken a leap into the magical world of tunning. Rough start

2008 envoy Lh6 gen 4. AFM DOD delete. M code engine & trans from an identical vehicle.

Engine: stock stage 1 non-DOD cam, new non-DOD lifters, rods, rockers. Heads ported and polished. New coils spark pugs and wires, new injectors, oil pump & timing chain, new cam and crank position sensors. Trans rebuilt al local trans shop.

Pulled tired M code engine and transmission, and replaced with above described engine.

Toggled the following: P3400, P3401, P3425, P3441, P3449, P3457
Now no start. Please advise
thanks Mark

Set all the DoD codes to no error reported. Then turn off the master drop down in the fuel - lean/fuel saving tab.

You did use a 4X cam gear correct on this new camshaft swap right?

Did you post the right file? That one has nothing in the change history log, and none of the DOD stuff is turned off. Maybe try posting the file you last wrote to the vehicle, instead of doing a fresh read after the flash.

I don't think a mismatch between DOD settings and DOD hardware will cause a crank-no-start. Does it have spark? Does it run if you feed it some brake cleaner? Does it set any codes? Do you have any logs of it cranking and failing to run?

thanks for the help.
1) pcodes for DOD are off, disabled fuel saver also
2) yes for sparking
3) starter fluid did not make it start

attached files.
thanks for the help Mark

Quote:

---

Originally Posted by MarkBarge

thanks for the help.
1) pcodes for DOD are off, disabled fuel saver also
2) yes for sparking
3) starter fluid did not make it start

attached files.
thanks for the help Mark

---

While it doesn't matter you did time this 180 out. One more crank rotation it will be good but it should look like this.
Then I always take a metal ruler and align dead center off the cam center to make sure it is perfect. With it at the top there is more room for error.

Attachment 133111

How did all the MAP & MAF codes get changed to No Error Reported? Think it'll run good without either of those?

You did change P3400 & P3401 to No Error like you should've but P3425/P3441/P3449 only got the SES box unchecked, they are still MIL On Second Error.

If you have the stock file you pulled off the truck before you changed anything, please post it. There isn't a '08 5.3 Trailblazer/Envoy file in the repository and I don't like wondering if what I'm seeing is real or a ghost.

Hello
attached stock tune,
Picture of the timing

Thanks Mark

You do realize that the first file you posted had zero changes made for DOD, and the second one only had half the changes, plus other stuff changed that shouldn't have been touched, right? Zero acknowledgement so far on any of those issues.

I think I would try changing the MAP & MAF codes back to Second Error, and all the DOD codes that got overlooked to No Error and see what happens. If it still didn't run after that I'd be adding some channels to the scanner to get some kind of idea what's missing that shouldn't be.

The mention of 'new crank and cam sensors' tweaks my feelers a little bit. Given the times we're living in, always assume new electrical parts are defective until you can prove that they aren't.

Quote:

---

Originally Posted by blindsquirrel

You do realize that the first file you posted had zero changes made for DOD, and the second one only had half the changes, plus other stuff changed that shouldn't have been touched, right? Zero acknowledgement so far on any of those issues.

I think I would try changing the MAP & MAF codes back to Second Error, and all the DOD codes that got overlooked to No Error and see what happens. If it still didn't run after that I'd be adding some channels to the scanner to get some kind of idea what's missing that shouldn't be.

The mention of 'new crank and cam sensors' tweaks my feelers a little bit. Given the times we're living in, always assume new electrical parts are defective until you can prove that they aren't.

---

Yes sorry, i did not mention I was grasping at straws with the MAP & MAF!! https://forum.hptuners.com/images/smilies/banghead.gif
Now thinking about this when the engine starts (as previous with the AMF DOD the lifters would not be collapse assume) Therefore, I would not think just the cam and lifters would not prevent starting. Iam thinking you are correct to look at the new cam and crank sensors.

Thaks Mark

If you set the master DOD to disable it will ignore the P3xxx solonoid codes if not set to NER and will not set those codes. I've tested that on many different years and OS. It is still good to set them to set them to NER but that alone will not prevent it from running. I've seen plenty of trucks start and run with DOD deletes done on the stock tune with DOD still set to enable. They will set the codes and will run on 4 cylinders, but they will run and idle so that is not your issue.

Hello to the helpful Tuners.
Per TheMechanic's post I have torn into the front of the engine and indexed cam 180?. I have loaded the original program deleting DOD. Truck starts and runs terrible:( Please see loaded program and VCM scanner. Any help is greatly appreciated. The most painful lessons are the best.

The cam goes '180 out of time' with every other revolution of the crankshaft. You can't get the cam 180* out.

Dot-to-dot is TDC compression #1, both dots up is TDC compression #6. This used to matter on Chevy engines with a distributor and where you timed the engine by the dots and then dropped the distributor in pointing at #1... and then found it was timed 180* out. Because you lined up the dots for #6 but put the distributor in thinking it was timed for #1.

Mr Blindsquirrel thanks for that information. just for clarity here is where the timing is physically, see attachment.

Any suggestions to work out the very rough running.

Thanks Mark

The only way you can get the cam and crank out of time on a pushrod V8 is to put the marks something other than either dot to dot, or both dots up. Either way is correct. The only time it matters which of those you use is when there is a distributor, and the distributor gets installed with rotor at #1 when the engine is actually at TDC #6. A cross-plane V8 has four pairs of companion cylinders, where there are two pistons at TDC at the same time. One will be TDC exhaust, other will be TDC compression. Turn the crank one revolution and the one that was at TDC exhaust will then be TDC compression, and the other one that was TDC compression will be at TDC exhaust. Each pair of cylinders flip-flops every crank revolution. Your problem is not cam-crank timing and never was.

You changed a whole bunch of parts that you probably shouldn't have - coils, injectors, cam/crank sensors - and these days new parts, especially new electrical parts, should always be assumed defective until you can prove that they work. All that did is introduce about two dozen new unknowns. I think you got some wiring mixed up, or have some bad new parts. Trouble is, by doing all this you're miles away from finding a good starting point to begin diagnosing.

Have you done a compression test and/or leakdown test? Pushrod length? How many turns to bottom out the rocker bolts after zero lash? Basic mechanicals first, then other stuff.

Got it clear, not timing! I will start with the basics as you have listed.

Thanks Mark

Quote:

---

Originally Posted by MarkBarge

Hello to the helpful Tuners.
Per TheMechanic's post I have torn into the front of the engine and indexed cam 180?. I have loaded the original program deleting DOD. Truck starts and runs terrible:( Please see loaded program and VCM scanner. Any help is greatly appreciated. The most painful lessons are the best.

---

I said in my post it doesn't matter that it is 180?. What I was trying to convey is that having the dot at the top "might" make it more difficult to see that you are off 1 tooth. That is also why I use a steel ruler through the center of the cam because making that mistake cost time. Time is money. Money is life.