94 Explorer 4.0 Eddie Bauer Bogs down uphill

[Gabe79]

I have a 94 ford explorer with a 4.0 that I have been working on since January. It has a rebuilt transmission, rebuilt engine and several of the fuel and air mixure components have also been replaced; after several codes kept coming up. My last replacement was the DPFE sensor and fuel filter which finally cleared all my codes. I took it for a drive yesterday and the pick up response was excellent, definitely better than before. Upon attempting to pass up an 18 wheeler on a hill, it did not want to respond very well. No misfire whatsoever and the rpms did not go up nor down, It just did not want to go passed the truck. Once the road leveled out, it picked up speed and I passed it up like nothing. What am I missing ? Someone mentioned Catalytic Converter... I have not checked for fuel pressure and have not replaced the fuel pressure regulator. NO CODES. BUT does it mean it's not faulty ? Any suggestions would be greatly appreciated. I'm new to this Forum and I thank you for the

 

[trashtruck]

you have a 5000# vehicle with a 6cyl. it's not designed for high speed hill climbing. that being said if the fuel pressure is good and you can verify nothing is hanging up like brakes or a bad shaft then i would look to the air flow either intake or exhaust.. just out of curiosity what gears are in it?

 

[natenkiki2004]

Did the trans kick down when you floored the pedal? If not, kickdown cable needs adjusting. It may also be that you have crappy gears like 3.27 or so that would just be a pig for torque at speed.

 

[Gabe79]

you have a 5000# vehicle with a 6cyl. it's not designed for high speed hill climbing. that being said if the fuel pressure is good and you can verify nothing is hanging up like brakes or a bad shaft then i would look to the air flow either intake or exhaust.. just out of curiosity what gears are in it?

Air intake was replaced and modified with a cone air filter (cold air intake style), cleaned up MAF sensor, throttle body was removed and cleaned thoroughly. I'm not trying to race it, "stock" but I would like to be able to pick up speed and pass up vehicles on the highway if needed to. And I agree with you on.the truck. Wing super heavy with a light engine.

 

[Gabe79]

Trashtruck, I forgot to mention that I does have a new Flowmaster on it.

 

[Gabe79]

Did the trans kick down when you floored the pedal? If not, kickdown cable needs adjusting. It may also be that you have crappy gears like 3.27 or so that would just be a pig for torque at speed.

Honestly I can't recall if the transmission kicked down or not. I will take it out for a spin tonight and update. What is and where is the kick down located ? How is is it to be adjusted?

 

[natenkiki2004]

Just gotta throw this in; a cone air filter is not a cold air intake. Stock is a cold air intake, it is on most vehicles, certainly ones made in the last 30 years. The exception to this is if you actually routed new tubing to outside the engine compartment and placed the cone air filter outside the engine compartment.

Kickdown is adjusted by pressing down on the grey half moon button on the kickdown cable where it comes through the firewall in the engine compartment. While pressing the button, pull the cable towards the front of the vehicle. Get in the driver's seat and floor the accelerator pedal (engine off). This should adjust it properly.

 

[Rhett]

It sounds like it wasn't kicking down, so I would adjust it as mentioned above.

Another thing you might look into is the throttle cable mod -- if you have a lot of slack in your throttle cable, your throttle plate in the TB will never open as far as it should/could/would. This can cause a problem when you're on-throttle, like in a passing situation. There is also a thread on TPS calibration on this site, which when done with the throttle cable mod, can help a lot. At least it helped my truck a lot.

You probably do have 3.27's. The trick is to get up speed before the hill.

 

[92exp4x4]

My sport has 3.08s. Terrible acceleration/ passing power, great top end and highway fuel economy.

 

[2stroke]

I love low gearing, but I don't think its as big a deal here. My daily driver has 3.27's and it can pick up speed up decent hills. I could see where it wouldn't be fun in colorado, but I doubt you see hills much bigger than I do.

 

[Gabe79]

Just gotta throw this in; a cone air filter is not a cold air intake. Stock is a cold air intake, it is on most vehicles, certainly ones made in the last 30 years. The exception to this is if you actually routed new tubing to outside the engine compartment and placed the cone air filter outside the engine compartment.

Kickdown is adjusted by pressing down on the grey half moon button on the kickdown cable where it comes through the firewall in the engine compartment. While pressing the button, pull the cable towards the front of the vehicle. Get in the driver's seat and floor the accelerator pedal (engine off). This should adjust it properly.

So i took my baby out for a spin lastnight and well, I noticed just as you mentioned. It wasn't kicking down, so i adjusted the kick down yesterday and it helped out a lot; thank you for the advise.

 

[Gabe79]

It sounds like it wasn't kicking down, so I would adjust it as mentioned above.

Another thing you might look into is the throttle cable mod -- if you have a lot of slack in your throttle cable, your throttle plate in the TB will never open as far as it should/could/would. This can cause a problem when you're on-throttle, like in a passing situation. There is also a thread on TPS calibration on this site, which when done with the throttle cable mod, can help a lot. At least it helped my truck a lot.

You probably do have 3.27's. The trick is to get up speed before the hill.

My throttle Cable was loose when I fist started working on it and I did adjust the slack a few months back, it was quite a bit. Throttle cable mod ? I'll look into the TPS calibration. What should I be looking for ?

 

[Rhett]

My throttle Cable was loose when I fist started working on it and I did adjust the slack a few months back, it was quite a bit. Throttle cable mod ? I'll look into the TPS calibration. What should I be looking for ?

The throttle cable mod involves putting zip tie(s) on the pedal end of the cable. There is about 1/4" to 1/2" of slack from the factory at this spot. putting zip ties around this slack space makes the TB plate open immediately upon pressing the pedal. It won't make your X a speed demon, but it will give instant pedal, which some people like. I suggest you search for the threads on it, they have pics etc.

The TPS calibration involves using a voltmeter on the TPS wires, to get a certain voltage when the throttle body plate is fully open. There is an ideal voltage reading the TPS is supposed to send, when the throttle plate is open all the way, and I can't remember offhand what the voltage was. It's in the threads here on TPS calibration. Keep in mind that the TPS can be moved slightly because of its two mounting screws -- it's been a LOOONG time since I did that so my memory is really hazy. The info is here on EF though.

 

[Rhett]

I love low gearing, but I don't think its as big a deal here. My daily driver has 3.27's and it can pick up speed up decent hills. I could see where it wouldn't be fun in colorado, but I doubt you see hills much bigger than I do.

My truck sucks in Colorado. Well, not off road, but on-road, on I-70, near the Ike tunnel, my top speed is 50 mph above 8,000 feet. I'm ok with that, because down in Denver I can reach normal interstate speeds (70-75 mph). And if I'm driving a steep twisty pass like U.S. 6 or Berthoud, I'm not doing over 50 mph anyway.

 

[Gabe79]

The throttle cable mod involves putting zip tie(s) on the pedal end of the cable. There is about 1/4" to 1/2" of slack from the factory at this spot. putting zip ties around this slack space makes the TB plate open immediately upon pressing the pedal. It won't make your X a speed demon, but it will give instant pedal, which some people like. I suggest you search for the threads on it, they have pics etc.

The TPS calibration involves using a voltmeter on the TPS wires, to get a certain voltage when the throttle body plate is fully open. There is an ideal voltage reading the TPS is supposed to send, when the throttle plate is open all the way, and I can't remember offhand what the voltage was. It's in the threads here on TPS calibration. Keep in mind that the TPS can be moved slightly because of its two mounting screws -- it's been a LOOONG time since I did that so my memory is really hazy. The info is here on EF though.

Yes I had already done the zip tie mod but I need to recheck that cause it seems a little loose once again. I will look into the TPS calibration because I did swap it out last week. Getting my Cat checked at the moment. We shall see.

 

[natenkiki2004]

So i took my baby out for a spin lastnight and well, I noticed just as you mentioned. It wasn't kicking down, so i adjusted the kick down yesterday and it helped out a lot; thank you for the advise.

Sweet! I know mine is a pig even with 3.73 gears when it's in OD. Once you get it to kickdown, there's some good pickup there. Kinda sucks since the 4.0L's torque drops off in the higher RPMs but it becomes a balance.

 

[malohnes]

Tps voltage is supposed to be .96 volts at idle to 4.8+(IIRC) at wot with smooth ramping up as it opened.