98 start-up smoke, and highway issues...

[Obo]

I recently purchased a 98 6.5l. The issue of white smoke at start up i believe is due to a couple glow plugs not working correctly, cause it seems to go away after its warmed up and the smoke definatly smells like fuel. Also it idels rough for about 20 seconds, basically missing on more then one cylinder. secondly i have a issue of the truck jerking or hesitation, but it only happens when not under load and your trying to maintain a certian speed, and that speed has to be above about 63 mph. Going down hills its terrible. With a trailer on it, such as my boat it works fine. there are no codes being thrown. The previous owner took it to the dealer only to be told it needed a new injection pump, and that there was rust in an aux fuel tank. i had the tank cleaned and there was nothing in it. before i take on the wonderful cost of a new injection pump any suggestions would be nice.

[Marty Lau]

Change fuel filter, check lift pump and could be injectors, how many miles on Truck?
In the members area of TDP there is check list of things to check and last item is IP (injector pump). You should also post basic info about truck, type, year, miles, mods, ect. That makes it easier to help.

[Obo]

fuel filter has been changed, i am pretty sure its not the lift pump cause it does it with both tanks, there is the stock tank then an aux tank and pump in the bed. the truck has 82k, ck2500, and as stated in the last post is a 98, 6.5 l. no mods yet, not until i ge tthe bugs fixed anyway...

[ucdavis]

Obo-
You said the magic word, or in this case the magic number: Less Than 120,000 miles. You are entitled to a new injection pump compliments of GM if the dealership can reproduce the symptoms w/out codes (or w/codes indicating the IP). Go to Members Area & scroll down to the Reference section; you'll find the Warranty doc there which you can print & take to a stupid dealer that hasn't heard of the warranty & is too stupid to check his web-based tech support on this topic. Before going, however, you may find it usefull to go over the Stalling article in the Reference section and learn your way into the problem. You may find it is something else and save yourself the trouble and possible expense of the dealer locating alternate (non-warranteed) problems. Its always best to know more than the dealer, better to know at least as much, and good to know something.
Welcome aboard. Wealth of knowledge here for the asking.