Engine/Transmission (1998.5 - 2002) missing at idle only when warmed uo

[TSkeen]

I have a high miles 02 auto with FASS fuel system, edge with att,installed at same time. The IP was only a few miles old at time of install. Truck runs great but misses at idle after warms up,,,sounds like it could quit running sometimes. Couple of shops think its the IP but I hate to swap it out because the truck runs so well. Has 11 to 13 LBS press. You can pull truck down into gear and the miss goes away. any ideas?? Tim S

 

[bnbrown]

I had a similar issue with my '99 (250k miles), started having a slight miss only at high altitude (8k feet and up) at around 150k miles, miss slowly became more noticable and at all altitudes whenever at idle and operating temp, would go away under any load (AC Comp. kicking in etc. ). Started having hot start slowness at around 210k miles... then VP took the short walk at 250k.
I was hoping it was just an injector or something up till the hot start problems.
Are there any codes present? If I remember right I had a mistiming code once or twice.

 

[TSkeen]

thanks for your imput. Truck just runs so good. I think I will just run this IP into the ground till it gets worse. No codes in 50,000 miles. When cold no miss... under any load ... no miss... just at idle in park or nutral... when warm

 

[bnbrown]

I would do the same thing... just keep the $$ stashed aside for when she goes, dealer will want $2500 for a replacement, MWFI I have bought 2 from and work well @ $1050

 

[LowFly]

I would pull the injectors and have them ballanced checked... ... OR find someone with a scan tool that they can shut down each cyl and find the problem child..... then swap the injector to another hole and see if the problem follows... ... . that would help elimate the injectors at least... and they are slightly easier to R&R than an Injection pump.



But with a IP that is getting long in the tooth... . you always have to keep that option open. You have the right idea... run that puppy into the gnd... . it will get worse if it is the IP... .

 

[bnbrown]

I had the wife sold on the idea of just replacing the injectors with 275's to make sure that wasnt the problem But IP went before I got around to it.

 

[obert]

I've had this since the VP was replaced in '01. Posted about it a few times, never get a good answer-- no codes or any thing ugly, and engine runs great. And I've herd alot of 24v's do this.

There seems to be a consensus that the later VP's "just do that. Its normal". Normal, perhaps, but that dont make it right!



bnbrown>>> when was your VP replaced? (date) The new one does not have any missfire?

 

[TSkeen]

I think this is IP # 3 but could be # 4 as one was under warranty. This rig has 289,000 miles. Just put a transmission from Dave Gorend about 25,000 miles ago ... what a nice upgrade... I also have a 06 and cant wait to try his trans in the third gen truck. Smarty on level 3 ... for now.