Ya what he said

 

...last thing could be the "Y" in the fuel tank. Sometimes one of the pumps develop a crack. Your high-side pump may have the crack at the outlet of the pump. In my case, it was the low speed side.

 

ditto on the chip.
Is your chip secured w\tape?
Have you reset the PCM (unplug battery for a few minutes)


*NOTE: (the reason I asked if it was chipped)
I had the exact problem and it turned out to be the chip. Eventually it got so bad my truck would die when I went WOT. However it was always fine under normal driving.

I got rid of the chip (got a predator) and problem solved.

 

This may not be the problem, but my truck and a friends L both had studdering problems and turned out to be the green wire going to the EGR layed against the hot tube going into the EGR valve and melted it so that the vaccum would not work. A real easy to spot problem. The green wire should be wrapped in a black wire loom on the drivers side in front of the metal tube going into the EGR valve which goes into the side of the plenum.

 

This happened to me a few years back, with basically the same mods. It actually died on an impromptu full throttle romp on the highway. Thought I blew the motor. The first thing I did was replace the fuel pump relay in the fuse block since I had one in the truck. Then I replaced the pumps with Walbro 255's and has driven great ever since.

 

I did everyhting you asked! I took the chip out and drove around a bit and it was the same! It was like it never mattered even if the chip was there or not! I took the chip back to the programmer guy and said he'd check it up and have it ready by monday! I am going to tear this truck apart untill i find the problem! I'll get the fuel filter changed (again!) and then get the relays of the fuel pump checked but only after the tune is ready!

Just ONE important question left...


1) Is it possible that the tune can have such a dramatic effect on the truck?!


It's really bad! It shudders like hell at wide open throttle! Im using 93 octane fuel on a 6# pulley and on a JLP CAI, Headers, Mac Exhaust... Why is the porgramming so important (dump question i know) but i wana know what the chip does specifically to the engine! How it controls it... What timing it changes etc...

Thanks guys! Any help appeciated especially on the previous questioN!

 

had the same problem... i had 3 bad coil packs.... it will do it more once it gets hot right?

 

i had the same problem and it ened up being my coil also

 

Yes it kept kicking alot more when it got really hot... Please guys! I need an answer to the previous questions i asked bout the WOT problem...

Thanks...

 

I know of one truck that misfired only at WOT, but at most ranges ran & idle perfected.
No bad codes were found or displayed.
Plugs & filter were changed--coils were checked and found to be OK--still same problem---leak down and compression tests performed and showed all was good in the engine---since there are basically three groups that make an engine work (fuel, electrical & compression), it narrowed down to electrical or fuel, but the mechanic working on the truck "strongly" felt that the problem was mechanical and in the engine---Well engine got pulled and once the heads came off, the problem was found---one of the heads from one of the eleven (11) 8mm bolts that holds the intercooler to the upper manifold "somehow" fell off and went into one of the cylinders and danced around for awhile before it came out in two pieces that was found lodged in one of the converters. Hopefully this is not what is wrong w/ your truck--but issue sounds very close.

 

Just ONE important question left...


1) Is it possible that the tune can have such a dramatic effect on the truck?!


It's really bad! It shudders like hell at wide open throttle! Im using 93 octane fuel on a 6# pulley and on a JLP CAI, Headers, Mac Exhaust... Why is the porgramming so important (dumb question i know) but i wana know what the chip does specifically to the engine! How it controls it... What timing it changes etc...

 

It's good to know it's not just me. I'm having the same problem on a mostly stock 01, no chip or pulley. It's under warranty so I took it in for an engine light. After they changed the SC gasket it would run great up to 9/10ths, but put it to the floor and nothing but sputters. Took it back, shop had it for 2 weeks and sent it to the dealer on two different occations, couldn't find anything. They say they "reflashed" the computer and the sputter isn't as bad, but the truck still goes nowhere in wot. When my 5.0 did this it was a bad spout connector. So I'm thinking coil packs as well. Anyone have advice on how to test these? MiMik; good luck, update if you find a solution.

 

No Not Likely that wont be the problem. im tellin you have the coil packs checked...

that what it does... at WOT, its shudders more than likely u have misfiring cylinders. which is either Plugs or Coil Packs... Coil Pack are more often the problem...

if you need to get ahold of me my s/n is SRT10ETR on AIM

John

 

Having same symptoms and issues.Ran code ..nothing. Check Fuel pressure and was a strong 55lbs at wot never dropped and with new filter.Changed both relays for pumps.
I run 94 shell. Previous owner/dealorship had changed cats ,plugs and several coil packs I assume to fix the same problem but still missed it. I found this out after when my friend ran the vin at his dealorship to look for recall and service history.
There has got to be a simple or fast way to check the coils which simulates boost load and high rpm. Idle is great & cruising at 70 got 14mpg on the 870 mile return trip.
It still shutters under load of WOT.
This sucks.I have a self learning trans and a garage door opener and the coils cant register a code? Something seems left on the table at the design meeting.