seems like I have no power above 3k RPM

[rkneeshaw]

I just bought this truck last fall and it was in shambles. I've got it running fairly good now (after new plugs, coolant temp sensor, cleaned MAF, new air filter, cleaned IAC valve, new O2's, new fuel filter, injector cleaner treatments, maybe a few other things, cant remember, its a long list). It idles great, seems to run smoothly, and no CEL.

My problem is that the motor seems to have no power above 3000 RPM. If I need to pass someone, I pass in 4th gear and at 2500 RPMs, becuase if I shift into 3rd with 3000+ RPMs, I really go nowhere.

Is that normal for the 4.0L OHV motor? Or should I be seeing more power at 3500-4000 RPM than 2500 RPM?

 

[FordBoy]

it sounds to me your running out of fuel pressure. if you changed the fuel filter on it already, then i would put a gauge on it. i could be wrong but its supposed to be minimum 30 psi depending on year up to a minimum of 60psi fuel pressure.

 

[LittleHorse]

I think for a '94 it should be 40psi with key on engine off, then drop 8-10 psi at idle, and jump back up in varying amounts as high as 40 in response to opening the throttle.

Mine has the opposite problem - no power until I get to 3000RPM...but I've narrowed it down to leaky injectors. So I'm always dumping fuel in and have to be doing 3000RPM for the fuel mixture to be even close to correct.

 

[rkneeshaw]

Ha, I figured it out. I was laying there in bed thinking about it, and dawned on me, my gas pedal doesnt have a lot of travel to it.... Sure enough, had the wife push it to the floor and its only opening the throttle plate maybe 65% of the way.

Threw on a couple zip ties around the top of the throttle cable above the gas pedal to remove some slack, and this thing is like a totally different animal. It WANTS to go now! weeeeeeeee!


PS I'm going to check the fuel pressure anyway, this is good info and its an old truck, so I want to make sure its where it should be. Thanks guys

 

[Slysdexia]

Ha, I figured it out. I was laying there in bed thinking about it, and dawned on me, my gas pedal doesnt have a lot of travel to it.... Sure enough, had the wife push it to the floor and its only opening the throttle plate maybe 65% of the way.

Threw on a couple zip ties around the top of the throttle cable above the gas pedal to remove some slack, and this thing is like a totally different animal. It WANTS to go now! weeeeeeeee!


PS I'm going to check the fuel pressure anyway, this is good info and its an old truck, so I want to make sure its where it should be. Thanks guys

Mine had a similar issue, but wasn't that bad. Same method to correct it, however.