distance on full tank vs gauge

[Wambliokiye]

I do not know if the E85 tables are in your engine's computer. That's something to check out. If they are, then I reckon all you need to do is put on the fuel injectors from the L9H. You might be better served by posing these questions over at the performancetrucks forum.

So here is a question? She has been acting up lately. At an idle its not smoth! Kinda rough with a little shake. Not bad but I noticed it the other day and I was not sure if she wants a tune up or a dirty filter like fuel filter. I also noticed a small leak that when I only park in my drive way backed up fine but pull in straight it shows. Drive way has a small slope. I squeezed my fat ass under and noticed some oil? I have checked all liquids and all show fine. So I am going to do a tune up! New air filter, oil change, fuel filter, belt cuz her is kinda cracked, plugs and wires. Should I change out the packs? She's a 6.2 no rotor or cap. I wanna do the trany filter, right? Or at least have that checked too. I know alot of the rubber under her needs replacing too! Any other suggestions? Her a.c. compressor has kinda a wine sound wd40 that ***** or do you know of another lube to help the wine? Also I think the boots are going out/bad too. The other night I turned sharp leaving a parking lot and herd a pop pop noise. I all of a suden I looked like a tweaker crawling all over my truck looking for a lost bag! ( in a park I g lot ) driving with door open hanging out of it trying to fine the sound! The boots seam fine. No leaks or grees any place. So any thoughts? Besides the pop pop, tune up? What plugs, I forgot the fuel treatment you said too. What else do I look for? Thanks for the replies.

 

[swathdiver]

A rough idle can be attributed to a vacuum leak somewhere and or broken engine mounts. GMT900s do not have an external fuel filter that can be changed anymore. You can run a couple bottles of that Super-Tech Fuel-Injector cleaner in your tank (Walmart) and see if that cleans up the injectors some. Oil leaks are usually attributed to the engine oil cooler lines that run from the oil pan to the radiator. The engine oil pan and valve covers can also leak. No need to change the coil packs unless the engine has a miss. A Tech2 can test your coils, injectors and see if you have a vacuum leak along with a host of other things.

Is your Denali AWD or 2WD? Did you also check the differentials and transfer case fluids? Current plugs are 41-110 and they come pre-gapped at .040". Check the gap but do not set it as the tip can easily break. Replace the wires as well. Try to use GM/AC Delco OE or AC Delco Professional line.

Let's see what the other guys say about the AC compressor and that pop pop noise.