I just put the fass system on my 01 and i am very unhappy with it . I lost 3 mpg total and it seems like my truck is slower than it was with stock pump.

I got this due to recommendation and testimonials by everyone and it seems to be not all that. Anyone have the same relation?

 

Please tell us more about your mods and upgrades so we can have the complete picture. Also did you get the FASS pump or the total kit?

Thanks!

 

i've got a edge comp and afe intake, 5 spd. i was getting 21mpg at every level power ciyt or hwy and now down to 17.3 after fass. my truck factory gets 18.5.
The truck seems like it lost a lot of power afterwards.

What do you think?

 

i have the whole kit.

 

Are you getting a LOT of smoke when you get on it?
Are you driving it like you had been, or like you stole it?
Stock turbo?
Stock injectors?
What AFE system do you have?
What are your fuel pressure readings now?
What was your boost readings before, and after?

I am just trying to get a feeling for what is going on. Its kind of like you calling the doctor and telling him your sick and expecting him to just be able to tell you whats wrong over the phone.

We will try to get you back to where you were or better.

 

I assume you did tap the pump wire, right?

 

Less smoke than before injector wire is tapped, 15psi fuel reading, boost i don't know i don't have a guage on yet. I drive it like a baby most of the time and i dog it once in a while.if i dog itr fuel goes quick.

 

i have the top afe # 7 i think the best one they made.

 

thanks for trying to help!! I do diesel mods and this is the first fass i put on for my second 24v. I am getting f1 injectors later for it but all is stock basically.

 

Sounds like something is not wired or connected the way it should be. This is due to only having 15psi and it dropping when you get on it. That sounds more like a stock lift pump than a Fass system. It should not drop at all.

I know you did this already, but double and triple check to make sure everything was plumbed exactly as it should and go over the wiring too.

It sounds like a simply missed step somewhere that is not allowing the pump to operate like it was designed to.

And yes, it always could be a defective unit because that does happen with everything that is manufactured. Have you contact DPP about your problems as well? They very well could tell you to send it to them and they would replace it with another.

 

i was going to call tomorrow i was refering to the fuel mileage dropping when you get on it. I checked everything over and it's a simple design so i;ll see what happens when i call.
thanks

 

I just don't see how a different fuel pressure on a VP-44 can effect mileage. It can run with no LP, and you don't even know the LP is dead.

 

thats what i thought!! All i did was the pump and i dropped 3mpg

 

Just out of curiousity, is this mileage drop recorded after you filled the tank since your change to the FASS. If not, it could be because of the fuel you lost when you made the change, I know when I did mine I lost a fair amount that seeped out of the lines when disconnected, not to mention the amount it took to fill the filters. Don't want to sound like a smartalec, but that could be the source.
Good luck.
mishkaya

 

I'm with Geico on this one
Just changing the LP to a FASS wont cost you milage if your driving habbits are the same. Its only supplying fuel to the IP not putting it in the engine. Now if your stock LP wasnt suppling enough fuel and your engine was down on power because of it then any functioning LP will note a difference but your power levels will be up also.