Bogged Down

[jdchristian3]

when ever my wife's 99 upshifts the engine shutters badly. i am a detriot diesel mechanic, but not good with the HEUI fords. it feels kinda like transmission slippage, but, i know for a fact that it is not. i have spent countless hours with it on the weekends, but no results... its getting old... any info would be greatly appreciated...

 

[Greenbeast6.9]

Turbo shot?

 

[h2odrx]

does it have a cat?

 

[jdchristian3]

here's the story: my wife's parents bought the truck this time last year. it had 194K on it and was a one owner... it had a superchips programer with it and supposedly it had only ever been on the "tow/haul" mode. it only has stock, towing, and hi-po modes. they traded it to my wife for her 94 chevy half-ton. so she started driving it. it was getting 7mpg. it also had a k&n replacement filter in it. i checked it and it looked to have never been cleaned. so i put an "intake-kit" on it with a big conical filter. that got it up to 10mpg. next thought was the EVIL catylitic b/s. i cut it off and gutted it. it was pretty nasty clogged. that got it to 12mpg. then it started doing the warm-up exhaust restriction crap and wouldnt go back into normal drive mode. then the shuddering started. then the weather warmed up, and the warm-up b/s quit. at this point i asumed trans problems. i built transmissions before going to DDC. so i figgered when it went i would beef it up. about 2 monthes went by of shuddering. then the front seal took a dump. i pulled it. rebuilt it. trans-go'ed it. and installed a triple-disc billet convertor. shuddering still there. MODIS scan-tool for two weekends of driving proved trans aint the problem. i hate computers. PCM was next. it checked out fine... trashed the superchips. reflasded to pcm with updates. installed an EDGE plug-in module. shuddering went away for 3 days. then it came back worse than ever... i dont have the money to just throw parts at the piece of crap. maybe waste-gate issues. i just dont know anything about these engines.

 

[jdchristian3]

oh yeah! fuel pressures are ok. cylinder cut out test is ok... it makes around 15 pounds of boost with 5000 lbs behing it... even with the edge box on the highest levels, it doesnt smoke like i thought it would. to me that is a good thing because smoke is just like throwing money out the window at 65mph to see it fly... but, with as much of a power gain as it should give, it oughta smoke like a perverbial freight train...

 

[BigRigTech]

Can you explain the details of the shudder? things like duration of the shudder after a shift is made, how much throttle is applied and etc? All gears or certain ones....Haveyou checked for seized or dry U-joints? I saw the same thing in an 03 Dodge - a bad u-joint was the cause as hard as it is to believe....Drove it myself and I was puzzled.

 

[geonc]

Does it shudder only when shifting under a heaveir throttle?

Does it make a "chchchc" or "pspspspst" sound?

My bud about freaked out when his '01 would dump boost under hard acceleration after his chip install.....He was running a generic chip.....

What color is the fuel filter and fuel in the bowl?

As far as the chitty fuel mileage/performance, there is a micro mesh screen on the outlet side [drivers] side of the fuel filter assy, on the block with a schrader vave...place a white paper towel under best as you can---remove the 2 bolts [10 mm head] and gently seperate.....there will be a small o ring and the screen that is prone to being plugged with trash--- the reason for the paper towl is so if the screen or seal ring falls out, you will see it and not loose them in the "valley of death" once you do that,remove the schrader and connect a mechanical oil pressure gauge...needs to be around 65/75 psi at high idle---just like those "Driptroit Greasels" ...I was a field tech with them for 14 years--hi perf marine and gen tech.

i am a detriot diesel mechanic, but not good with the HEUI fords.

These are not much if at all different than the DDEC....in the series 60's.

 

[jdchristian3]

it shudders on every upshift under load, at any throttle position. it shuddered even with no tuner at all, just the factory programing... i'll check that screen and oil pressure...