getblown5.9

well after a frustrating night at the track where the truck will not run right above 2500rpms/40psi, i still cant figure out whether its the drag comp or the VP44 thats the problem.

on top end its missing, you can feel the truck surging and hear it in the motor. it doesnt do it with the drag comp off, or on 1-3 settings. on 4-5 tho it does it and its quite noticable along with lack of smoke thats normally there. i notice as well a lack of boost, only 42 psi with WG disabled where as it was hitting 48-50 a week ago.

i just cant figure out if its the comp box, or if its the early signs of a VP going south, and the high setting of the drag comp are amplifying the effect.

any idea?

(sounds like its time for a TST/smarty)

Gene007

My EZ Comp is doing the same thing at this time. My HRVP is brand new. So I'm sending my Comp in for an upgrade. It sounds like your Drag Comp maybe getting weak.
Gene

kelownadiesel

I thought the only problems with the comps were that the buttons wear out and you cant select settings.Doesnt make much sense to me that they would get weak as all they do is send signals and such.It sounds to me that the vp44 is getting weak and cant support higher fueling.But maybe the comp isnt advancing the timing properly

getblown5.9

well its gotta be the comp, this morning on the way to work it wouldnt even turn on until i got here and the truck was turned off with the key still on. i just had the drag upgrade done a few weeks ago, but i don't think it will hurt to have them check it out and reprogram it again. its either that or time to head into TST territory.

getblown5.9

let me also add that it was obvious that power wasn't there because ive always trapped in the mid 90's (93-98) and last night my first run seemed ok, no breaking up on the big end, and i went 15.6@93

second run the missing started, but i had a better launch and went 15.1@90

third run had my best 60' of the night and could only run a 15.9@87

Ph4tty

Sorry I can't help, but what was the 60'?

kantdrive55

Try disconnecting the pump wire to see if it is still doing it? If the missing goes away then it was the box. If it is still there, then check for pump codes.

getblown5.9

no pump codes, but ill disconnect the pump wire and try that tonight

BigBlue

I've got a feeling it's the comp. I've never heard of a VP doing something like that. Not saying it can't happen, just saying it doesn't sound normal. I'd definately look at the comp since you couldn't get it to turn on this morning. I say ditch the comp and go TST/Smarty but that's just my opinion.

getblown5.9

60' for the runs were

2.6 2wd 3rd gear

2.4 4wd 3rd gear (15.1 run, and it felt alot harder leaving the line, without the box acting up this was easily a 14.6ish run)

2.2 4wd 2nd gear

getblown5.9

Blue, trust me, if i had the money I'd do it. even just having a TST right now and stacking it on my comp EZ mode for timing would be nice.

BigBlue

Money? It's just green paper.

Tcolesanti

Forget the TST, find a used Redline box to stack with your comp in EZ mode.

getblown5.9

thats way too much money...double what the TST costs or else i would go that route...along with upgraded valve springs, twins, HRVP44

griggs43

i no its stupid but what about the fuel filter
i had simular symtoms of the topend when mine was cloged
ididnt think thats wat it was i had jus changed it 2000mile ago sure anough