Please can someone help me with my truck.

I went to the dyno and my truck leans out after about 4800rpms. The whole curve is flat at 11.8 A/F then at 4800 it goes to 14AF. I put in Walboro 255lph fuel pumps thinking that would solve the problem but went to the dyno and same thing.

I am running about 14.5lbs of boost. I am wonder becuase Ford installed the pumps that I brought to them ,I am wondering if they even put them in!! I am about to drop the tank tomorrow and find out.

Anyone have any suggestions??? I drive my truck but dont take it above 3000rpms to be safe.

My mods are 6lblower, ported blower intake.

 

Maybe you have a leakage in the system

Better to check the whole system ,maybe a bad fuel line

Or your MAF sensor could be bad

Johnathan

 

Maybe a clogged fuel filter?

 

My MAF maxes out at 4800 RPM and I start to go lean there as well.

 

Was your tune adjusted for the 4lb er? If not your MAF maybe pegging, also your injectors could be at the top of their duty cycle.

My truck with my MP blower and a 4 lb lower & 2.69 upper was pegging my MAF meter and it put my injectors at 98% of their duty cycle.

Hope this helps,

If your tune has not been dyno tuned you are at risk.

Peace,

Suavy

 

You need injectors.

 

I am making 400rwhp so the injectors are not tapped out yet.

Is there anythingI need to do to the fuel pump regulator?

I have the 255lph pumps and I am getting 33lbs at idle

 

Check the fuel pump relays.

 

hmm...

 

Two relays under the hood in their own box. I believe the relay closest to the front is the hi side relay, if it isn't working you will not get full fuel pressure.

 

What should fuel pressure be at wot?

 

I THINK, and I emphasize I'm not sure, but I THINK about 52?

Hopefully someone else will chime in.

 

At WOT your fuel pressure at the rail should be 40psi plus whatever boost level you are seeing...so at 14.5#'s of boost you should see 54.5psi. Have you been able to datalog your MAF voltage?

 

I have not logged a MAF % or tested fuel pressure yet. I will once I get my tune ajusted. I keep going way lean so I have to have some major timing taken out so I can go WOT

After that I will let you know. If I dont get good pressure, I will check the relays under the hood first.

Anyone know how much those things are?

 

We just tested Smoak's truck compared to mine. We were data logging on my Predator. My MAF was 4.5 at the shift @WOT at 5200 hitting 3rd (ish).

We tested Smoak's and it went to 4.7 at 3700RPMs and mine was 3.5 at 4000RPMs

2800RPMs 3.64
2980 3.76
3200 3.94
This next jump was not gradual and was a sharp spike we let off soon after
3220 4.5
3375 4.7 13 timing
3450 4.7

We are modded about the same

Thanks for all the help everyone.