ok i gotta question about it. i am fairly new so bear with me plz. i hear u guys talk bout defueling around 2700rpms or something. is this something you can feel easily, SOP, or what? if i mash the go pedal, my truck feels strong all the way to 3200 rpms when it shifts. i feel no drop off in power at all. i bought my truck used and i think its stock, i dont see any boxes on it, but it did have an after turbo pyro on it, and all the gaskets from engine to manifold to turbo are new. i dont have gauges yet but i did get an x-monitor for christmas that i havent installed yet. thanks in advance, this is a very informative site but i am afraid the bombing bug is getting near me...lol

 

I'm not sure about the auto's but i'll take a shot at it I would imagine if your truck was going to defuel it would happen at wot not during any of the shift points. hope this helps.

 

i forgot to say, when i first got the truck, it kinda died off at higher rpms, i found that the wastegate hose was off and the elbow was plugged, hooked it up and now it pulls hard til 3200rpms. and had overboost code which i cleared with scan tool, but it still comes back. thanks again

 

Do you have access to the owner before you? It would be a good idea to find what the did so save you $$$ or damage , its obveous that its not stock , with the waste gate being one , then the next is runing up to 3,200 hard , that tells me it minght have the 3,000 springs in it , find out if the trans. [ one of the weak spots] has been upgraded , they will last long with extra power.

 

dont have access to previous owner, i bought it from a small dealer in sept. i dont know what 3,000 springs are, i think those are for 12v right? mines a 24v 2000 . the trans has been touched, it has a blue convertor in it as the stock ones are bare metal, correct? and the trans is painted gray in color, im thinking it might just be a reman, not sure though. possibily an aftermarket ecm? i havent got a clue. thanks for the replies.
Bret

 

I didn;t catch that you had a 24V but the springs are one of the ways that they detune the eng. for the pickups, kind a a govener, starts defueling , stock about 2,200 rpm, kits 3-4 thou. RPMs.
So if you ever go to a 2nd Gen you'll have to put one of those on your list.

 

Without a box to over ride the defueling.. there are two points where your auto will defuel.
The 2700 is stock defueling for high RPM. I know that's for the 01's & 02's. I believe it's true for all 24v.
Also, if you power brake...build boost before releasing the brake...you may expirience defueling. It's protection against over torqueing the auto tranny.
If you can wind it out to 3200 rpm...I don't think it's completely stock.

RJ

 

i can wind it up to 3200rpms very easily and at anytime i want. any suggestions on places to look for non-stock stuff?
Anyone in Wisconsin near Madison or MIlwaukee maybe wanna eyeball the truck over with me for a few beers? lol Thanks again all

 

If you are on it hard (floored)from a standstill or powerbrake, you will feel it defuel, as well as going into 2nd gear, and at 2700rpm. I would suspect you either have a Drag Comp installed(eliminates hi end defueling up to 3200rpm) and haven't found it, or you lucked out and have a MAD ECM.

With the MAD ECM you will not have any defueling from takeoff, but depending on what injectors are in it, and what stall torque converter you have, it may overfuel(hesitate like it is defueling) from being floored also, and then go like a scalded cat , try easing into the throttle.

Try to get hold of previous owner from dealer to find out what mods, and check for your injection pump being tapped now. If it has MAD ECM, it may not show on sticker(mine didn't), but you could get # off of it, and check with dealer to see if it matches engine vin coding.

 

With overboost code...I'd say you have no chip(box). They all come with boost foolers. Look at MAP sensor plug (behind & below Fuel filter) on block-drivers side. If just one wire harness with just two plugs... no box!
Could be a MAD ECM.
I would not push it hard till I had an EGT gauge hooked up.
You might post another thread looking for knowledgable automatic owner in Wisconsin. I'm sure you'll find someone.
Might try these members...listed as N. Indiana Chapter of DTR.
https://www.dieseltruckresource.com/...ad.php?t=87277
I drive almost three hours to our club meets in N. Texas... well worth the monthly trip!

RJ

 

MAD ECM will not throw an overboost code, so that pretty well rules that out.

You will have to do some searching for other signs of box(like back of inj pump-older VanAaken), maybe it is missing boost elbow, or wastegate has been altered to increase boost, which will set off overboost code.

If you can't find any box on it, chances are previous owner took it off, but forgot about altered/disabled wastegate.

 

ur truck is a24 valve ..its all digital...its the 12 valve guys that have to worry about early defueling in stock trucks...u should have full fuel easily past 3000rpms

 

His year 24 valve has the defueling program built into the ECM(Part of the Torque Management Program), and will defuel at 2700rpm. With the MAD ECM, it is removed from the programming, and will continue to fuel even over 3200 rpm, as it will also do away with all Torque Management Programmimg at the bottom end.

Drag Comp is designed to override the 2700rpm defueling program, but only to 3200rpm on level5/sublevel5 only. To my knowledge, these are the only ones able to do this. Factory ecm will still fuel up to 3200rpm's, but will be reduced at 2700rpm's. Hope this helps to clarify it.

 

since you are new, what are you comparing the power to? SOP is very subjective.

even though i have a manual, i can rev it to 3200rpm anytime i want in any gear. just because it revs there doesnt mean its not defueling. it just may not pull as hard in comparison to truck that doesnt defuel. without another truck to compare to, it would be tough to say yes or no.

maybe go to a dealership/used car lot and find a truck similar to yours and test drive it.

take a look at your data link and MAP sensor as a box would plug in to one of those.

maybe injectors?

 

well, i was going by the way it felt. i dont feel any drop off in power when i accelerate hard. i had seen ppl talk about defueling on here and i just figured i would feel it. i drive racecars in the summer so i do have a pretty good feel of what is happening at all times. i just cant imagine that i cant feel it. lately i have been beatin her hard tryin to feel it

i did some checkin yesterday, and i found nothing plugged into the wire harness near the fuel filter and lift pump. i did find the empty 3 pin plug.
also the dealer must have reflashed the ecm shortly after is was bought new, cuz there is a sticker on the ecm as well as the radator support. so i assume that hasnt been touched either. but i did find( i think) that the wire has been tapped on the vp, cuz i found a female plug in spliced to it.

thanks again to all, Bret