Took the beast out for a good road trip to try out the new tires. She is running good now, but has picked up a weird miss which cause the truck to shudder.

It does feel and sound just like a miss, I know that it is a diesel but that is only way to describe it.

When driving along with the cruise set at 75, when I hit a hill, the truck will gradually accelerate, and it will miss a beat. Just like you turned it off and right back on very fast. Usually once, twice if the hill is long. If I accelerate harder it will not do it. Most often does it while gradually moving accelerator.


has new fuel filter ad cam sensor

runs great the rest of the time.

 

You might be describing a "buck" - this would occur at mild acceleration or a slight incline (moderate throttle setting). If so, the bucking I've experienced has occurred with one of the following scenarios:

• Bad injector O-rings
• Loose injector
• Imbalanced tune (non-stock)

 

Did the 99 6-speeds use a dual mass flywheel? I see in your signature that your truck is stock.

 

99 did NOT use dual mass flywheel.

Ok I could agree with it being a buck. Will loose injector/o-ring run fine at idle and under heavy acceleration?

 

It depends upon how loose the injector is. If it is extremely loose it will do it most of the time but you will hear an additional knocking sound.

As far as o-rings are concerned, when is the last time that you changed your fuel filter? Was the filtration portion black? Are you losing/using oil? These are symptoms of worn injector o-rings and/or loose injectors.

 

Also, do you have the ability to monitor ICP, IPRDC%, FIPW, etc.

 

I am the loose injector king, so the frequency of my experiences with this is askew from the norm. An injector with between 80 and 100 inch/pounds on the bolt will cause a buck at light acceleration or up a slight incline, yet not give obvious signs at lower or higher power settings. It's a little weird that way. You might hear a louder injector on one side or the other, with the sound coming and going. A truck can run like this indefinitely, or the injector can work itself out - flip a coin.

Once you get about 75 inch/pounds or less on the injector bolt, a weird knock starts up (not the regular cackle - you won't be wondering, you'll know it when you hear it). Once you hear the weird knock, you can see the IPR signal ride higher than normal at idle - this is a big ICP leak getting by an O-ring somewhere.

That stage is followed by a bigger knock with a "tink" sound - and things go downhill from there quickly. Don't worry though, nobody else will know it's your truck making all that racket. The whole truck will be enveloped in it's own smoke cloud.

 

Fuel filter is new, I was not looking for oil at the time.

I did have a compression check done on the truck when i got it and they replaced one injector at that time. It was low on power and smoking then. Now it somkes a little when I forst start it, but nothing after that.

I have nothing onboard to monitor. I have a mech that is pretty good with the scan tools, he can probably do it.

 

so Tugly are you saying the safe bet is to retorque all the injectors?

I have not drivien this truck far enough for an oil change and have do a lot to it.

recap

bought it, it began smaoking with low power. Out of town so took it to a reputable powerstroke shop, they check comresion and replaced one injector, installed cold intake, exhaust, and a 6 postion tune.

I got it home and we installed a clutch(which slipped do to oil leaking at the HP, plus we did not turn the flywheel, they said oem is concave and their plates need plate). ut new clutches in the rearend.

Back on road it died, new cam sensor fixed it for a day, but f died again and we found a broken wire going to cam sensor from a peeled belt from a worn tensioner(still need to fix that btw)

On the road again, lost cruise, 4x4 and horn.

4x4, motor was out, cruise the connection under the brake master cylinder was dirty, horn unk at this time. Also replaced the clutch switch because we thought that was acting up.

New treadwright remolded tires in bfg a/t copied tread and drove it 500 miles. tires did good, truck runs great except for the occasional buck.

 

Does yours turn on the cel? Mine has just started this. Except the truck will almost die then I get the cel. But the scan guage doesn't see it? Mine happens at low rpm pulling away from a stoplight or after slowing around a corner.