here is my Graph, their graph was kinda hard to read, so i made my own on excel 274.8 hp 329.5 tq I believe the air/fuel is way off

 

Cant tell you about A/F but I do know that HP\TQ always cross at 5250RPM or some specific number between 5200-5300

 

yeah it should cross at 5252 rpm... b/c hp is a function of torque and you use this formula to get hp


hp = (torque (ft. lbs) x RPM)/ 5252

 

even if the air/fuel is wrong? cause if so,, then my HP should be like 320 something at 5252 rpm

what is causing my car to give out numbers like this?

 

They always cross at 5252.11 RPM. They have to. They have no choice.

HP is calculated from torque. The formula is

HP = Torque x RPM / (33,000/2pi)

Since 33,000/2pi = 5252.11, the curves cross there by definition.

You made a mistake somewhere in the graphing process. Post the raw torque numbers at 200 RPM intervals or however you have them.

A/F has nothing to do with any of this. What was the wideband O2 reading? Without that, it's going to be pretty hard to tell what the A/F ratio was during the pull. The usefulness of a dyno pull without that is pretty drastically reduced.

 

I changed the graph, i did graph it wrong, the new one is above... here are the a/f ratios

3000 14
3200 14
3400 14.1
3600 14.35
3800 14.85
4000 15.35
4200 15.9
4400 16.5
4600 17.6
4800 off the chart past 4700 where it is 18:1

 

It's lean, everywhere, but especially up high. You should have a A/F somewhere in the 13.0:1 neighborhood.

Looks to me like there's some sort of fuel starvation going on. It would be real helpful to have fuel pressure readings during the run. You could probably get suitable ones suring a 2nd gear run up an expressway ramp or some such.

 

wow...that is really lean up top. that is not good for business....

 

the fuel pressure is about 50 psi

perhaps it is wanting more fuel than a stock fuel pump can give

 

Is that 50 psi at idle; or is it what really matters, which is the pressure throughout the entire run?

 

well, not sure if this is the same, but when i rev the engine to like 3000 or so RPM it still says about 50... so does that mean it stays there?

 

No, it is definitely not the same. THe engine's fuel flow requirement is probably 5 times greater at least when under full load compared to just winging the throttle on an unloaded engine.

I doubt your problem is the stock pump, unless you have a blower and you're making more than 10 psi of boost, in which case you may need well over 50 psi so that there will still be 50 psi more fuel pressure than air pressure in the intake. I'd suspect either a clogged fuel filter, or a dying pump.

In any case you need to get it taken care of right away, before you end up with pistons with holes in them. At your moderate HP level I don't see a need for anything beyond a stock pump, although that's your decision to make. It does seem like aftermarket pumps are a reliability problem when used in daily-friver applications though, if that's an issue in your situation.

 

the pump was put in in june or july, and the filter was put in in april or may.... so i doubt either one of those are bad...

 

Do a couple of 2nd gear blasts up an expressway ramp or something with your fuel pressure gauge taped to your windshield. Find out what your FP is with the engine under actual full-load operating conditions.

If you find that your fuel pressure is low, then ..... your fuel pressure is low. You need to find out why and deal with it. If it turns out that the filter is restricted or the pump isn't working right, then .... the filter is restricted, or the pump isn't working right. Being relatively new doesn't somehow relieve them of being at fault for being bad. No matter whether you just replaced them yesterday or they have 200,000 miles on them, if they're not working right, they need to be repaired or replaced.

 

My problem is very similar.

(Good compression, vacuum, fuel presure, new filter).

I'm thinking if a bad spark plug wire can cause the same lean condition as a bad fuel presure?.

How can I do test a bad spark wire?.

Please, please, help me please.

Thanks in advance,


Denis V.

 

No. That can cause a misfire, can't cause a lean condition.

 

You have made some serious changes to the engine from stock. Also upgraded fuel injectors and have a custom PROM. Probably gutted the MAF too.

All of these are adding up to where you need to get a proper tune done on the PROM. Either DIY or find a dyno shop that can do it for you.

The lower RPM range lean-ness is probably from either the gutted MAF or the injector constant (PROM calibration), or both.

The higher RPM range lean-ness is probably from maxing out the MAF. When this happens the ECM doesn't add any additional fuel beyond that point. You need to use some PROM tuning tricks to get around that.

RBob.

 

Ed Wright did custom tune my prom.... and I have decided to get a better fuel pump... a 255lph one... i think that should be good

 

When you say custom tune, he did it with the car or engine in his shop on a dyno? If that is the case and the AFR suddenly started to go lean, then yes, I agree with the fuel pump (and possibly fuel filter).

RBob.

 

well, he did it off of my specs...

 

Might want to try your stock chip then.

 

stock chip would not give the right amount of fuel with 30lb injectors... am i right?

 

Hard to say...

Maybe you should invest in a PROM burning setup, and use your dyno time to do some tuning. The best chip burner in the world can only guess what your motor needs, if he can't run it and see what the results are.

It sure isn't right like it is now, that's for certain. Something is out to lunch.

 

well, i have made up my mind, i am gonna get a walbro 340 fuel pump, and then see how things go

 

Dude, your problem isn't maxxing out the maf or something magical in the chip . I've talked to several dyno operators and 95% of the time someone is missing hp, it's due to a fuel problem. That's your problem, so your'e on the right track about checking out your fuel pump. Yeah, you can gain hp and tq from the chip, but I wouldn't say more than 20, 30 tops. You're missing about 80hp and 80ft lbs at the tires. That's something that ain't going to be fixxed by fiddling with the chip on a MAF car. SD is different, though.

 

if the car is misfiring then the oxygen level will be high in the exhaust.when a car misfires ,air just passes thru an engine without combustion thus, the oxygen sensor will read higher.

id make sure u have adequate fuel pressure at full load.
then id start checking the ignition system.

 

The oxygen sensor isn't in the picture at WOT.

 

no body said anything about miss firing.... i do not think.... but i have got the pump on order, so it should be here soon

 

thats true at wot the pcm goes into open loop.the oxygen sensor still reads at open loop but the pcm doesnt use that information.

 

well i got the new walbro pump in and it still had the same air/fuel problem.... actually less hp this time.... so i am changing the fuel filter, and then gonna run it on the dyno with a fuel pressure gauge on it to make sure fuel pressure is not falling off...

 

What's the deal w/ your regulator, have you thoroughly checked it for problems? Maybe those damn Ford injectors are shot. Did you buy them new? If so they're ususally very reliable. Are all your injectors firing? What do your plugs look like after you made those dyno runs? Sounds like your engine just can't get any gas.

 

well my MAF sensor was bad.... it was maxxing out at 165 gram per sec.... put on a new MAF and the a/f ratio went to 13:1 all the way across the board

 

Much better. What kind of power readings?

 

Thats good to hear. Those AFRs you gave are very dangerious. I was going to suggest not to do it again unless you want a pile of parts on the ground.

 

You need stop posting before someone dumber than you believes you and does something stupid.

the chip isnt magical its just pretty much EVERYTHING when it comes to tuning your setup.