Frustrated: 7060 $85 intermittant problem w/log and datastream glitch. Please look!

[chevmasta]

Since I've started tuning this 93 K3500 7.4l 4l80e with the 7060 PCM I have had nothing but problems. Either it's my stupidity, or I have some bad luck.

I've replaced every part except for the wiring harness. And have rewired SOME of the wiring. Please help me.

I have two problems.....which could be related....but the main problem is a random check engine light with the engine going into limp mode (I believe). I can be driving down the highway and see the light blink for a second, wideband freaks out....the truck falls on it's face and then it's all over and runs like a top. just like that.
....Or at a stoplight....check engine light comes on...truck will die/stall out and i have to restart it. Then it runs like a raped ape. There's no rhym or reason.

I'll offer a $100 paypal reward if you fix this truck via the net.

I have a Moates G3 adapter with the EX switch. I've tried various chips....29F040 and 27F512's. (seems to do it worse with the new 29F040?) I'm almost thinking it's a hardware problem at this point. I think I'm going to put the stock memcal back in and drive it for awhile to see if it does it's funny business.

Mark has noted a datastream glitch during a previous review of one of my logs. (hot hesitation, I think it's this exact problem tied in) and a code 51. So I replaced the PCM and the datastream glitch is still there.

Here's the log and the files I'm using. I think one problem I'm having is the $85 isn't as developed as others.

To pinpoint the log down faster, pull up "engine runtime" as a "value" in the dash monitor.
Go to an "engine runtime" of 274 seconds. This was the longest it's ever acted up....about 6 seconds till 280 on the "engine runtime". In this example you'll see the rpms were about 1600 and then the truck nearly shuts off. RPMS all over the place. Fuel gets pulled out. Datastream glitches with various "errors" in the item list. error codes 15, 21, 39, 42, 43, 45, 51, 54, 59 get thrown at random times then turn off..

If you do a "frame by frame" "Shift + ]" key. The SECOND "engine runtime" LOG of 33 seconds you can see the datastream glitch. All the numbers in the log go weird? WTF?

Then it also freaks out again at 350 seconds. Sitting an an idle, check engine light flashed, RPM's dropped and then it was all normal. Didn't die/stall......just freaked out!

Take a look......

In need of some major help. I'm about to give up and tap out.

Ryan

[Six_Shooter]

Have you tried a different ECM?

I have a friend that between his car and his GF's car, he had two '7060s (conversions) running without the issues you are describing.

One of the first things that comes to mind is a poor ground, either to engine or the chassis, that is causing a ground potential shift and the PCM can't deal with it, but this is difficult to diagnose without having hands on the vehicle in question. Something else to check is the alternator, not just that it is supplying current, but that the output is as smooth as an alternator should be, to be more correct that vehicle voltage is smooth. A ripple on the voltage can be caused by a bad diode in teh alternator, and/or a weak battery, and this ripple, if it's large enough can cause the PCM to have issues.

[EagleMark]

I have a Moates G3 adapter with the EX switch.

Put in a G1 adapter and chip!

Did the issue start with these parts?

May have time to look at your log tomorrow...

[chevmasta]

Have you tried a different ECM?

I have a friend that between his car and his GF's car, he had two '7060s (conversions) running without the issues you are describing.

One of the first things that comes to mind is a poor ground, either to engine or the chassis, that is causing a ground potential shift and the PCM can't deal with it, but this is difficult to diagnose without having hands on the vehicle in question. Something else to check is the alternator, not just that it is supplying current, but that the output is as smooth as an alternator should be, to be more correct that vehicle voltage is smooth. A ripple on the voltage can be caused by a bad diode in teh alternator, and/or a weak battery, and this ripple, if it's large enough can cause the PCM to have issues.

The PCM is a reman from Autozone a few months ago. I put it in after Mark and I had a conversation in one of my other 7060 threads. $99 and they had it in stock :wow:

I know the grounds are good. I've put a dual battery setup in the truck with all new battery cables (welding wire). So atleast I know the battery to frame, battery to block and battery to chassis grounds are good. I have not started checking grounds at the PCM yet.

Is the PCM case supposed to be grounded?

Alternator is a reman. it has been on there awhile. Honestly, elk hunting is a few weeks away. I'm not opposed to just changing the damn thing.

Put in a G1 adapter and chip!

Did the issue start with these parts?

May have time to look at your log tomorrow...

Thanks for the look Mark....

I would use a G1 but I'd really like to have the select-ability of the G3 with the different maps.
I never had this issue with the stock memcal....
however, it took awhile AFTER I started tuning that this problem showed up. So I'm not sure if its related or not. it used to do it only when HOT and towing. Now it's even more often.

I'll do whatever it takes.


[/URL]

[chevmasta]

Just got my wideband installed this week to revisit the WOT and Pump shot AFR.

[Six_Shooter]

Do NOT ground the PCM case, that will (in most cases) cause problems.

The case is grounded through the harness and internal circuit board, but it needs to be isolated from the chassis directly to help shield from radiated noise.