1st post after reading thru about 40 pages of threads. Got tired and just decided to ask. 99', K&N, 4" all the way back, edge box (was on it when I bought it), 135k. When I start it up runs fine, drive to town and first light i get to hit the clutch and take out of gear and rpms are a little under 1000 then 4 or 5 seconds later rpms drop to 750 or so and begins to miss. Have replaced lift pump, checked injectors, ran Stanodine cleaner through to no avial. Even took it to a diesel mechanic and hes not sure. But thinks it may need new fuel pump. Don't really want to spend that much money if there is no guarantee that it will be solved. Thanks in advance.

 

Turn your key on and off 3 times without starting the engine, on the third time leave it in the on position and read the codes on the odometer and tell us what they are.

 

im not sure, but i dont think the key trick worked on my99. might have to get a code reader.

 

Autozone will read your codes for free... or just buy a reader and have it when you need it. Thats what I did...

 

My mechanic hooked up to diagnostics to check codes and said no codes came up. Heading to Co. in a 1.5 months towing 15k lbs, so I would really like to get it fixed and hopefully make sure she doesn't lay down on me. Its been acting like this for awhile. I just don't drive the truck that often.

 

Have you checked your fuel filter and what is your fuel pressure at wide open throttle?

 

Not sure what pressure is, before replacing lift pump it was 6 @ idle and dropped when throttle was applied. Thats why we replaced lift pump. I need to get pressure guage installed. Just so **** busy.

 

here's what u can do: first, find out which of the injectors is not firing by cracking one line at a time at the head. when you find one which causes no drop in rpm, that is the one you will want to reseat the injector cap and tube. if you still cannot get it to fire, the problem is most likely caused by a worn injector whose pop pressure needs to be decreased, adjusted.

 

I'm going to pile on to this thread because it sounds like I might be having the same problem... This may be a long post, sorry in advance...

My 98.5 stock truck is missing occasionally at idle. I received the truck from my father with this condition at 180,000 miles and it now has better than 200,000. The ONLY modification has been an aftermarket air filter and at some point I'm sure the lift pump and VP44 were changed (I'd have to go look through the records for dates and mileages.)

Truck starts and runs fine. It pulls everything I put in/on it well an exhibits no ill effects while under load. But at idle, only when warm, it misses (sometimes). Not only that but I think it's the same cyl that misses because when it does it a lot, it's a regular beat. Once under load, and I mean any load it goes away. If the defroster is on, then when the compressor switches on the missing stops. It comes back again when the compressor stops. When the tranny is in Drive, it does not miss. With tranny in neutral or park, it misses.

The above post suggests that the pop pressure in one of the injectors may need adjusting. (get 'em all rebuilt- I know)

Does this sound right?