Engine/Transmission (1998.5 - 2002) Same power with different comp setting.. Need help

[fj40charles]

I dyno'd my truck last weekend and got the following hp numbers.



Comp on 5x5 = 322 HP

Comp on 1x3 = 324 HP.



See sig for details of my Bomb. Can anyone explain what is going on? I have a pusher pump and have about 21 PSI of fuel pressure at idle and never gets below 8 PSI at full WOT on 5x5.



I've replaced the comp box. The little wire is connected on the comp box.



I'm thinking it might be my VP44, but the darn truck runs very well and never has any problems starting. I don't want to swap it out unless I know for a fact it is bad.



I know the injectors are good because when I dyno'd last time with an EZ and DD2's, I got another 20 HP more from the previous run with an EZ and DD1's.



I replaced the MAP sensor and reset the APPS. The truck smoke much more on 5x5 so I would think it is not a Comp box problem.

Also, the max boost on dyno was 30 PSI and the wastegate is disabled. I can hit max boost about 30-32PSI on 1x3 or 5x5. It doesn't matter.



Anyone on have an idea? I'm thinking I have a fueling problem.



Charles

 

[Chipstien]

Your symptoms sound like there is not enough air but with your turbo then that is not the case. The fact that you are not getting more boost tells me that you are not getting more fuel. Sounds like level 1 and level 5 are the same and you the reason you are getting more smoke is you are using different sub-levels. Did you try dynoing on 5X4? The drag version only effects 5X5 so maybe there is something wrong with the drag software. Either way it is either the Comp or the Dyno. Maybe someone else will know more.

 

[KatDiesel]

Have you or do you have access to another box to plug and play? Just to test. Since you said the smoke level does change you would think the COMP is working, does anyone near you have the injection pump tester from Cummins?



Is 32psi your boost limit on the street as well?



What RPM's were the two peak hp readings at?

 

[Snow man]

Did you verify that you have 12V+ on the pump wire tap? You should have 80-90 more hp easily on 5x5 than level 1. I cant believe you have any smoke on 1x5,once under boost,should be zero smoke under boost. i only get a faint haze on 5x5 with dd3s,B1 and drag comp. I think you shouldd also have 40PSi of boost with 5x5. I still suspect the pump wire tap.

 

[Bob Wagner]

I agree with snowman, the wire tap may be to blame



you should be over 400 HP easy

 

[Greg Boardman-RIP]

Charles,



It sounds to me like you might have tapped the wrong wire. It will smoke more because of being on sublevel 5. It would run like it is an EZ. Check if you unhook pump wire and let us know what you find... Good luck, Greg

 

[fj40charles]

Thanks for the replies. The max HP was at 2700 RPM for both settings. I'm using a blue chip pump cover and I tested it using a light. Maybe I need to meter it to make sure it is 12volts.



I did not dyno on 5x4. I guess I should have tried it.

 

[JR2]

My first drag comp box was like yours. It made decent power but did not seem to make any more power on various settings. It did seem to smoke a bit more on various setting but really did not feel like it had more power. None of this was verified on a dyno, but it was the seat of the pants meter. I sent the comp box back and the one I got back from them was much much better. Another thing you could try is to swap boxes with someone else. I did that and that is what made me decide that mine was kaput.



Good luck.



John

 

[fj40charles]

Anyone near Dallas, TX have a comp box I could try?