Anything other than idle and it sputters...

Hello tuners.

I have a 5.3/4L60 out of a 2000 Yukon I swapped into a 1969 G10 van.

I replaced many parts on the top end. Swapped to a Summit 8719-1 Truck cam (mild) with new lifters and pushrods and all the gaskets and timing set and oil pump... Installed cam straight up.

It fired right up the first time I tried to start it. Idles good, but even though it is set at 850 in the ecm it runs up as high as 1300 and hangs there. Repeated attempts to change this have failed.

I was reading other posts and saw a similar post where the PCM was not reading the throttle position sensor (testing this confirmed a reading of 0% open even when trying to work the throttle). That post mentioned that the computer was looking for drive by wire input (And yes I did just notice a P1518 DTC on the error list today) instead of monitoring the TPS on the throttle body. Is this causing my stumble?

The only thing from the swap I did not use was the 2000 Yukon PCM. I had grabbed a PCM out of the junkyard from a 2001 Denali and used it for the swap, but weren't all the pre 2003 stuff drive by cable? It was a Red/Blue PCM just like my original. I thought these were a slightly more versatile PCM for future mods which is why I used it. Is this where my error is? Do I need to go back to the other PCM?

I did just reinstall the HPTuners software with the advanced options, so now I can see all these options that were mentioned but invisible..

Any help is appreciated! Tune and log uploaded.

The Denali trucks and the SUV's did get drive by wire before the P59 switch over in 2003 in the trucks.

This computer you have right now is drive by wire. You can click the systems tab, then system options and there is a "1" in the ETC column. You would have to change that to zero and write back to the computer if you are using drive by cable.

You would have been better off starting with the 2000 computer because that was drive by cable. This computer you have now is also setup for a 6.0 engine and you will have to copy over data from a 5.3 tune file to make it correct.

Thank you for the quick reply.

In your experience will I save myself headaches just spending the $90 for the credits to crack the Yukon PCM and program it, or would switching the engine to 5.3L in the system menu be sufficient?

Use what you have now to see if it works, you already spent the credits on it.

Change the system options to zero because it's drive by cable.

The drop down for 6.0 to 5.3 does nothing, everything else has to be changed still. The easy way to do this is find a stock 5.3 file from a 2001 Yukon/Suburban with a 5.3. Open that file with the compare feature when you are looking at your current tune. Click compare again and view comparison log. In the new little window you can collapse all the boxes, right click the engine icon and you can copy all the 5.3 information into this 6.0 tune file.

You are awesome! Thank you so much!

Should I just read the info off the 2000 Yukon PCM I have and copy that way or do I need to use a 2001 Yukon scan since the PCM is a 2001?

Use the same year files.

A 2000 uses a different operating system than a 2001 vehicle and there are many differences between the two so not everything would copy over right.

That was absolutely my problem.

I need to adjust my VE tables back down some, but it idled beautifully at 800-850 RPM and had great throttle response like I had expected. I will find those other specs and swap them over soon.

Thank you so much 5FDP for your help! So happy to have it run like I expected!