4.2L engine issues

[Jumbie65]

First posting for me here,
I just did some major work on my 04' GMC Envoy SLE. I replaced the front cover, oil pump and pickup tube (installed a Melling oil pump and pick up tube), found a broken chain tensioner shoe ( the plastic part was broken and was sitting in the oil pan) so I replaced the chain and all the related parts ( aftermarket items used) along with a rebuilt exhaust cam actuator and gear ( GM rebuilt unit). I replaced the VVT solenoid because it was leaking oil into the electrical connection ( AC delco VVT installed). I got everything together and it has started and I have no codes. However, the throttle response is not good and I seem to only get about 3000 RPM and it stalls at idle sometimes with the AC running. There is a little hesitation throttling up with a little rattling sound before the throttle up. I'm thinking I may have the timing off a tooth... I did check this several times before I buttoned everything up. Is there a way to check the timing without tearing this all down again or should I just dive back in and see what I could find? Let me know your thoughts on this...
Thanks

 

[Mooseman]

With the battery disconnected while working on it (I assume), did you clean the throttle body. Required anytime the battery is disconnected.

 

[Jumbie65]

Yes... I had the battery disconnected and I cleaned the throttle body as well.

 

[Mooseman]

Do you have a way to see live data, especially short and long term fuel trims? Did you check for vacuum leaks?

 

[mrrsm]

When you did the Dis-Assembly and Re-Assembly of everything this work entailed... Did you follow any Threads, Download Manuals or use any "How-Tos" posted here at GMT Nation during the job? The reason I ask is that if you can provide a Thumbnail Sketch of how you went about doing these things... we might be able to spot any problem areas sooner than later; some as obvious as asking whether at any time... Did the Timing Chain become loose enough to slip free from the Crankshaft Cog?

Also... it is a bit confusing when you mention" Used-Aftermarket" in the same expression in relation to which Timing Chain Tensioner you chose as a replacement part here. As you can see from the attached images... anything other than OEM Quality Part(s) here might glean an unanticipated negative outcome:

Here are Two Different...Brand New Timing Chain Tensioners. One is the ACDelco OEM flavor... while the Other is made by Evergreen...Which is Rubbish... you can see the obvious differences in the quality (or lack thereof) between these two supposedly "New" Parts:

 

[Jumbie65]

Guys... Thanks for the replies. Well I didn't really follow any threads here. I looked at a few posts but mainly was going out of the Haynes manual. As for the parts, I used a set up from Ebay for the chain and tensioner. What I didn't do was to match the tensioner to the one that came out of the engine. It looked like the same thing so I went with it. I took everything off and replaced all the timing components with these parts. I matched both gear timing marks and assembled everything. I made sure and checked the timing marks several times before installing the front cover.
Looking at the photos I can see the obvious differences, I'm already not a happy camper about that. One thing I could say is that I have all the tools here and it looks like I may be diving in and redoing this thing. So it is possible that this could have jumped timing on start up...
Okay Mooseman... I did manage to record some live data but I haven't checked for vacuum leaks as yet. I can say that I cleaned up everything and installed a new GM gasket and replaced the hose on the manifold with a new one. I think I may have loaded up too much data but that is the first time doing that with my scanner. See the attached files...

 

[Mooseman]

That was a lot but it was fine. Fuel trims look OK except for one blip of the LTFT at 25%. Temps seem to be low around 170 but does climb to 190 and go down back to 160. Maybe your thermostat is sticking?

I wouldn't worry too much about the chain tensioner. My original was bad at the ratchet and would let the chain get loose at idle, making noise. It never skipped. I don't remember what the one I installed looked like but it worked fine. It's just made differently. Look at it this way, I used a no name timing set from eBay.

If you want to check for proper chain timing, just do a compression test. I think it would run like total crap or not at all if it was off.

BTW, you do know there is a rev limiter while in P or N, right?

 

[Jumbie65]

I had read about the rev limiter when I first started researching the rpm. In all honesty... this engine runs so smooth. While I was doing the work I replaced both engine mounts because I knew the others were getting worn out. I replaced them with OEM mounts. I left the brackets in the chassis off just in case I had to go back in. I'll get an OEM thermostat installed and then get this car out for a test. I'll report back with some new live data.

 

[mrrsm]

This Video will interest you... For others following this Thread, follow the OP's lead and Skip the Murray or Stant path here by replacing the Thermostat only with the OEM ACDelco Part imaged below. The OEM Flavor has the"O" Ring Tucked nicely inside of the ACDelco "O" Ring Groove... so you don't have to play "Blind Man's Musical Chairs" while trying to wrangle a loose "O" Ring properly in place B4 bolting the TS back up to the Engine Block:

 

[Jumbie65]

Thanks guys... I have a AC Delco thermostat on it's way from RockAuto!