Recently purchased a 97 F350 crew with a 460 and a Vortech supercharger, Vehicle has a manual 5speed with 3:55 rear end.

Vehicle was running flat at 3800 RPM in 3rd and discovered the T-Rex pump was not working. Replaced with new pump and vehicle was instantly a different beast. However it did not last long. I switched to my secondary fuel tank and the vehicle started to run rough. Figured there was air in the lines from the 2nd tank due to the pump replacement, feathered the pedal and she started to run properly. Turned vehicle off for a short while and then restarted with success. Drove about 3 minutes and the vehicle died as if it were out of gas. Would not restart.Towed home. Restarted vehicle following day and vehicle will run ruff unless rpms are brought up to 2-2.5k but only for a short while and it will die out as if it were out of gas.
Not sure what exactly is going on or if it is related to the new pump or not. I did have a couple of shut offs before the replacement that may be related. Once at a stop light it just died as if it were out of gas and twice in the yard at idle.

Fuel Regulator? Fuel pump relay? FMU?

 

Sorry i'm not familiar with the dual-tank setups.
And IMHO theer are better ways to give more fuel than a troublesome FMU, so I run with a larger fuel pump.

But it does seem to be fueling.
Does it run correctly on one tank, but not the other?

 

Thanks for the reply. I decided this evening to replace the fuel pump relay located in the power distribution box and like magic my problem went away. One of the few times in life a repair only cost $8.

Once again thanks for the help! I am sure that I will need some additional help in the future. It is the first time that I have owned a vehicle with a supercharger and I am trying to make sure that it is all working properly. I will be taking it back to the dyno next week now that I have the fuel pump issues resolved.

I am curious if you could provide some insight into the use of this supercharger and a speed density motor?

 

how does that run with the Vortech, aside from the problem you posted about. i have a 97 350 with a 460, i'm thinking about the Vortech.

 

Still sorting it out, but it definately runs better with the problem fixed. I have not seen any fantatstic #'s on the dyno yet but I have not had a chance with the new fuel pump installed.
But I am pleased with its overall performance and expect it to only get better the more I work with it.
I wil try to keep this thread updated as things progress.

 

Need to know a little more about your combo (fuel system, ignition and any aftermarket tuning)...

 

Not sure about the tuning, but everything that is there was part of the original vortech v1 S/C. MSD box, FMU, excluding the new T-Rex pump. I am still learning about the setup.
Purchased pick up from a dealer trade and kind of sorting it out as I go. I have had various input from differnet people and they have said that it would be a better setup if it were a Mass Air instead of a speed density. From what I can tell the install of the S/C was done properly and would figure that the S/C would work well with a speed density or they would have changed it to mass air (just my opinion).
Ideas, Opinions welcome!

 

Yes, speed density can work with a boosted application. I would recommend you run nothing less than 93 octane with a blower, especially if you're not running an intercooler.

I would also strongly recommend you investing in a wideband O2, to monitor your A/F ratios, and KEEP the fmu in place! I can tell you from my own experience that air/fuel ratios will change with the weather on a boosted/stock speed density application. With a boosted/speed density application, there are two ways to control the fuel: injector pulse and/or fuel pressure.
My guess is that you're running a boost retard and FMU (that can adjust the ratio of fuel with a plate change).
Are you running stock injectors?

 

I would assume at this point they are factory but would have to check it out. How would I determine the injector size by visual inspection?
When you say wideband O2 are you refering to a guage for air fuel ratios?
I am running a boost retard with the FMU. When you suggest plate change are you saying the fmu you can be modified to accomodate th weather changes?

Sarge

 

answered my own question regarding the wideband O2, did a little search and found the info.
what would be a recommended kit? (cost conscious)

 

I think 24lb injectors are stock for a 460, and they should have blue tops on them.

Yes...a good/accurate wideband will run right around $300. FJO, AFM and a few others work very well.

If your FMU is a Vortech unit, then yes. Changing the fuel ratio (12:1 to say 10:1) is just a matter of changing/removing the 6 screws and changing the plate. Vortech (and their dealers) have these available. The only way to know if the motor is running too rich or too lean is to get a wideband on it though.
Taking it to a dyno will definately help. A/F ratios can be displayed and you can make changes to your boost retard to dial it in properly.

 

I will check for the color on the injectors, If they are 24's are they sufficient?
How easy are these wb/o2 kits to use?

 

Sent you a PM.