Sad tale,

I just got home, I left the house 12 hours ago to take my truck in for a simple dyno tune.

When I took my truck in it was pegging the A/F at 18 volts, majorly lean.

After some tuning they got A/F down lot into the 14v area with about 230rwhp and 250rwtq at 5K PRM, not pushing it, no timing. They kept trying to get the A/F down but they couldn't. Changing my MAF for another 80mm didn't work, changing in a Lightning MAF didn't help either. They thought maybe I needed larger injectors as they could not get the computer to give the engine enough fuel.

After the best dyno run of 230 rwhp, things went down hill from there. No matter what they did, it kept getting leaner and leaner. Even backing up to a previous tune things got worse.

The guys at dyno are stumped. When I left my truck was not running, it kept stalling with the A/F off the meter in a lean condition. I ended up borrowing a Ford Escape (thank God for human kindness!, what a good group of guys at DaSilva Racing) for the 200km drive home.

I have some basic questions,

Is the 2003 Ranger a returnless fuel system?

Is there a regulator?

Is there a place to plumb in for a fuel pressure gauge? (even a temp one?)

Does the Fuel pump run at full pressure when the ignition is in the on position but the truck is not running? I am wondering if the fuel line can be pulled of the fuel rail and if a direct reading of fuel pressure can be done.

The stock injector size is 19lbs? The EE kit comes with 30lbs, should that be enough? Or might 36lbs or even 42lbs be required for over 250 HP?

What is the stock fuel delivery system capable of (liters or gallons per minute). How big of a fuel pump would you need for 250-300 hp? What is the form factor (fitment) of a Ranger fuel pump? What models can I use?

Does anyone know what the litres/gallons per hour rate is on the fuel pump supplied by EE? Brand?

One thing that I didn't remember until late in the day was that the guy who installed my EE kit complained that he had to remove the tank twice because he was not getting enough fuel pressure, a clip or hose had come off. I will not be able to check until Monday to confirm what problems he was having.

Since we didn't take a direct reading of the fuel pressure I don't know what it is, but they are convinced there is something seriously wrong with my fuel pump.

They are going to pull the tank on Monday and check the fuel pump. If they find anything wrong with it, I want them to just replace it. I cannot afford to keep dinking around with this, I just want my truck to run right.

Anyone know any specific makes and models of high quality fuel pumps that would fit my need?

I hope it is the fuel pump, then it is an easy fix. My biggest fear is it not being the fuel pump and then I have a dead truck.

Lest any of you think these guys just don't know what they are doing, there were high HP cars all over the place, being tuned without any problems. They went above and beyond the call of duty.

I need to get as much info as I can before Monday morning, I want my truck back! :(

Thanks,

David, Rangerless for the next few days.

Hey Dave,

Where did you go? Steeda CA? If so have them call me. Your fuel pump is plenty large for your Supercharger, Brian Mckelvey made 293 rwhp on his stock pump and his was in a 3.0 originally. I've also seen plenty of 240-260 rwhp 4.0's with stock pumps. Also the 80mm MAF is plenty large enough, there again at the mid 200's HP level the MAF was reaching into the mid 4.3-4.7 voltage range and it it goes to a full 4.9-5.0 volts. The injectors are plenty as well, 30lbs injectors on a 4.0 will support well up to around 300-325rwhp maybe more.

You definatly have a problem elsewhere, if it was going that deadly lean then I'd look for a opening or leak between the MAF and the TB or a vacuum leak around the S/C mounting flange. That supercharger is well within the 80mm MAF range and using a Lightning 90mm meter is just plane overkill but since you did try it and it didn't change then it's not in the Meter.

Biggest issue, call me or send me an email and tell me where you took it, if it's an SCT dealer I'll be happy to call them and help them with your tuning like I offered before. I truly don't think it's in your tuning though as I've done more then 10 of these kits now with your same tuning without any problems.

Thanks, Doug.

Doug,

Thank you for your offer to help, the shop is,

http://www.mustangtoystore.com/

(Steeda is closer, but their Dyno is still not up and running.)

The shop owner is Joe Dasilva and the tuners name is Diego. How can we/they get in touch with you on Monday Morning? (you have my email address)

They are an SCT dealer. My Blue tuner would not work with there system (could have been the USB to DB9 serial cable), it would not link up for communication. They ended up using the new SC2 hand held calibrator.

To rule out the fuel pump before they go to the trouble to drop the tank, how can they easily check fuel pressure?

Again, thanks for your offer to help Doug, I *really* need it!

David.

you can put a fuel pressure gauge on the fuel rail.

curt

They should have a guage that screws onto the back of the passenger fuel rail. There is a schrader valve back there towards the firewall with a blue cap on it (I think). Definitely check the fuel pressure, then check the voltage to the pump. Did they have a data logger to see exactly what the computer was doing? I agree with Doug, the 80mm is plenty good, I was using a 75mm. Tell the shop that it is a lot easier to unbolt the bed and slide it forward a few feet then to go through the hassle of dropping the tank (if they need to).
Jesse

When we installed the fuel pump on my truck, we also removed the bed, way easier than dropping the tank and only takes a few minutes. Hope everything turns out okay.

--Sean

Anything past 00' from Ford should be returnless fuel system. I would definitly look at that causing a lean condition, except it must have been running pretty good to drive it 200km over there. Some guys that swaped a 2.3T in 98' up rangers had problems with this, but if they installed the pump wrong they rarely got it to crank.