Defueling at 1900 rpm's

[N.E. TMRPR]

Last thursday I'm going down the highway at 80 mph and the truck loses power and I coast over to the breakdown lane, motor still running, check engine light on. I went to the Chevy dealer that my brother works at and I bought a fuel filter and went home and installed it. The truck ran like a raped ape but the light was still on. Went to the dealer and at closing time my brother put it on the tech II and the codes were large fuel leak, which I atributed to the filter, and over boost which happened when the truck seemed to disengage the trans when I was on the highway. I drove the truck the rest of the week and then last night went to pick up a horse an hour away from me. I pull out on the highway and go about 3 miles and low and behold it does it again. So now I think I've got a bad tank of fuel but I have a filter with me so I pull over and replace it. Pull out of rest area and it goes like a raped ape again for about 2 miles and bingo, it's back. Now I think I've got a clogged pickup in the tank so I dropped the tank this morning. What I find is a spotless tank and no sock, just a clean plastic screen in the sender-fuel pickup assembly. I'm going at 4:15 today to check the codes that I have. Last night the check engine light came on and never went out but it went out after I dropped the tank and it's running normal again. Last time, my brother only checked the engine codes and then cleared all. This time we're going to check both engine and trans codes and see what we get. Any ideas if we don't find anything. Thanks P.S. My truck has 78,000 and has been great till now.

[ 03-05-2003: Message edited by: N.E. TMRPR ]</p>

[N.E. TMRPR]

Sorry, forgot to add that the truck will only go 1900 rpms and 64 mph. Any faster and the trans seems to disengage and then the motor will rev a little higher than 1900. I did about 2 weeks ago have the NSBU switch replaced after it malfunctioned and put the truck in limp mode. Maybe there's a connection. Will try to find out later today.

[sdaver]

sounds like limp mode to me........and 3rd gear

[maxedbowtie]

My truck did the same exact thing at 1900rpms and 64mph last weekend ('sputter, sputter, sputter' post). Although, it didn't feel like the trans was disengaging. The engine would start sputtering and just stop making power a little above 1900, like the computer was shutting it down.

It reset and ran perfectly, with the exception of the cold sputter that still occurs in the low rpms after being totally cold.

Mine will be in the shop tomorrow to investigate more...

[maxedbowtie]

also, mine never went into limp mode...

[ 03-05-2003: Message edited by: maxedbowtie ]</p>

[AbqGeorge]

I'm getting suspicious of that quick disconnect fitting in the fuel line sucking air???

[N.E. TMRPR]

Here's an update on my issue. I took the truck in last Friday and went through the truck and could'nt find the codes in the history but the mechanic thought that the truck sounded like it had been fuel washed so he changed the oil and had me pick it up to drive it so we could get the codes to set again. Took the truck on a tow on Sunday and it went into the limp mode again. Dropped the truck off on Monday and they went to work on it. They changed the oil and sent it for analysis but the level hadn't gone up in the crankcase so that was good. The codes were large fuel leak and turbo over boost. They ordered a fuel pressure sender and turbo boost sender. The parts took two days. The dealer then called me on Wednesday and said that they had another truck come in with the same symptoms and when they spoke to technical they led the mechanic in a different direction. They believe that I have some injectors that are leaking at high pressure back down the return lines. They now have my truck and are tearing it down and putting on a series of tubes to test all the injectors. The tech said that he was told to replace any questionable injectors. We'll see what happens. I'll post the results.