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By kevin camps
driving a 97 k2500 camper special, 4l80e with 454 vortec
couple days ago I got in my truck after work and noticed it would stumble when hot, 100C no problem but a little bit warmer and i would have issues. always under load during acceleration. got home and idled in drive and it felt like an obvious misfire, RPM would drop to about 500. pop it in neutral or park and no misfire or stumbling, its been confusing me since in the mornings when i pull it out the garage it has no problems all the way to work (5 minutes highway and 5 minutes city) but end of the day and evening- same issue
bought the truck with 268km now has 276, oil change every 5000k.
did fuel pump (48psi at idle now) FPR, distributor cap and rotor, plug wires and plugs, ran seafoam through the intake and in the fuel tank.
ive heard of distributor gears going south but id assume then i would have the issue when cold too. runs like a top at any temp below 100C, no engine light, plugged the scanner in anyways and no codes whatsoever.
any help is appreciated, looked through forums for a couple days now but nothing exactly like what I'm experiencing.
I have a Silverado 1500 4.8L base model with 200K miles.
I could use some guidance on how to troubleshoot two engine codes that my truck has. P0101 and P0171. I erased the codes, unfortunately. This is what I have done thus far:
-Inspected the Air filter (it is clean)
- Cleaned the MAF sensor with MAF cleaner.
- The MAF values are responsive to changes in engine RPM.
I don't have any special tools to check for vacuum leaks.
I Took live readings with my Zurich ZR8 code reader
The LTFT1 and LTFT2 hover around +14% when engine warm and idling around 600 RPM. Drove around a little and LTFT1 and 2 rose as high as 21%.
MAP - 11 Hg
MAF reads 0.52 lb/min
TPS reads 9%
I tested the fuel pressure and it is in the normal range, 58 while idling, a bit lower with the key in the "On" position.
While running the engine, In short bursts, I sprayed brake cleaner around the air intake hoses and gasket and listened for changes in the idle pitch. Admittmedly, I may not have hit every crevice while doing this. No leaks detected.
What are my next steps?
I purchased a 2021 Silverado Crew Cab High Country 4WD about 4 months ago from Watson Chevrolet in Tucson Arizona. Within week of driving the truck I began noticing some pretty strange sporadic things happening. I started video taping the issues when I could to document what was happening. Ticking noise coming from the engine when cold starting, sporadically have hourglass on stereo saying “loading” it would continue until the engine was turned off and back on then it was OK. “Park Assist” Error message sporadically popping up while driving down the road, Horn honking (three short honks) for no reason while sitting in traffic at a red light. At 900 miles I reached out to the dealer and told them these concerns and issues I was experiencing. The service manager explain to me “the truck has a lot of technology and it just needs to learn your driving habits, you just need to keep driving it”
At 11,000 and 3 months after purchasing I get the loud lifter noise, “Service parking brake”message, “steering assist reduced” message, “Service ESC light” and “check engine light” I drove it into the other dealership located in Tucson (O’Reilly Chevrolet), they keep the truck for about three weeks and “replace lifters on one bank and 1 bent push rod” and tell me that they couldn’t duplicate any of the other issues however they did a firmware upgrade and everything should be fine. One week after getting the truck back (11500 miles) I get another check engine light, Keep in mind I can still hear the lifters ticking when starting it first thing in the morning. I take back to the dealer after a week of a being in the shop, They tell me “The check engine light was because there was multiple cylinder misfire and it was the opposite bank from the lifters they replaced” however they can’t duplicate the problem so there’s nothing they can do. They admitted that the computer had logged over 200 misfires on one cylinder and that’s what made the check engine light turned on, then they go on to tell me they can’t duplicate the problem so there’s nothing they can do. I asked them about the ticking noise when starting and the tell me “that’s normal, it’s not lifter noise you’re hearing, it’s the new technology fuel pumps GM is using that’s making that noise”
Other issue I have had is the rotors on all four wheels at times will turn blue and discolored as if the brakes and her have been completely overheated. But it’s not the entire rotor It’s only the center inch of all rotors. The inside edge and outside edges look normal.
I have a purchased over 11 band new (Ford, Chevy, Dodge, Toyota) Trucks in the past 30 years this is by far the worst freaking vehicle I have ever purchased.
Hello I have a 2000 GMC Sierra 5.3 4x4, it has been sitting for 6 months. First thing I did was change the oil, next I drained the old gas and put new gas in. The truck would crank but not turn over. I replaced the fuel filter, and replaced the fuel regulator. Prior to replacing the fuel regulator I had no fuel pressure, gas was leaking through the diaphragm of the regulator into the intake manifold. Once I replaced the above items fuel pressure was up to 50psi with key in start position. The truck fired right up no problem but, there was a very loud ticking sound that sped up and got louder when I pushed on the gas. I immediately shut it off. I checked the oil and the dipstick smelled like gas. I drained the oil and there was a lot of gas mixed in with the new oil. I replaced the oil filter and filled it with new 5W-30 Mobile 1 high mileage synthetic oil. It fired right up again and the loud ticking sound was still there. Oil pressure was good I let it idle for a few minutes and the ticking got a little bit quieter but, still loud. Check engine light was on and the codes were P0300 and P0200. I hooked up a Noid light to each injectors wiring harness at idle and every one was firing. I removed the fuel injectors and cleaned them, did OHM test on each one and all of them had consistent readings. I do not know what else to do from here? Any help, direction, or advice would be greatly appreciated. Thank you for taking the time to read this.
My truck has 245,000 miles on the original engine.
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