Problems with lack of power

[PetroleumJunkie412]

Pj.. Hope that acronym is okay with you.

Better than PetroleumFlunkie







Which..... ive been known to be lol

 

[reed b.]

To All- I do thank you all for your input. As you can see I have tried a few things already which unfortunately have not 'done the trick'. So I am open to any ideas, especially one's 'outside the box'. A question that came to mind- If the fuel pressure is within specs at no load is there a possibility that it might not be when under a load? Like I said, I'm trying to look outside the box... Thanks

 

[PetroleumJunkie412]

To All- I do thank you all for your input. As you can see I have tried a few things already which unfortunately have not 'done the trick'. So I am open to any ideas, especially one's 'outside the box'. A question that came to mind- If the fuel pressure is within specs at no load is there a possibility that it might not be when under a load? Like I said, I'm trying to look outside the box... Thanks

Hm. Pressure wouldn't be my concern, volume would be.

.....just out of curiosity, map sensor known to be good?

 

[lvwill]

Grey tfi is the correct one for your truck.

 

[RonD]

A gasoline engine will lose 3% of its power for every 1,000ft of elevation
So if you are at 4,000ft you're already at a 12% loss of power, and that's minimum, I would guess 15% would be more likely, as loss % increases over 3,000ft
After warm up check exhaust for Rich smell that would indicate an issue with air/fuel mix of course, and contrary to what many think Rich is bad in this situation, less power and low MPG

Find your vacuum gauge
At 4,000ft it shouldn't be lower than 16"

MAP can be tested with a Volt/ohm meter with a Hz setting, graph here: https://www.aa1car.com/library/map_sensor_ford.gif
The 2 outside wires are 5v and ground, test those first, key on
Center wire will have the Hz frequency signal the computer sees

Check key on/engine off Hz, at sea level it should be 159 Hz, at 5,000ft elevation 144 Hz, so 4,000ft should be 147 Hz
The computer gets this with key on to adjust for elevation

 

[rusty ol ranger]

This one is interesting.

Find your vacuum gauge....wonder if you got a clogged cat or something?

Other then that im out.

 

[reed b.]

Hm. Pressure wouldn't be my concern, volume would be.

.....just out of curiosity, map sensor known to be good?

 

[reed b.]

I have put a new high pressure pump in but haven't really checked the ones that are in the tanks. I did do one thing else which I don't want to think of as the problem. There is a small canister for a fuel filter before the pump. I had opened it up long time back and it had nothing in it. I did not want any junk that might be in the tanks to mess up my new pump, so I made my own 'conversion' since I was told that no filters were available by Ford. Their logic was that there was a filter after the pump so that was all that was necessary. So I used a smaller in height filter and painstakingly fit a bronze bushing into the housing to make up the difference. It seems I did okay since it only uses a 1/16th " o-ring to seal and I have no leaks. But what you've said about volume may need to be checked out. As far as the MAP goes the next thing to do is to find a testing procedure for it. I have another one from a donor Explorer with the same emissions data and had switched it out before but not recently. Okay then, I will switch it out first and see if there is any difference.

 

[reed b.]

This one is interesting.

Find your vacuum gauge....wonder if you got a clogged cat or something?

Other then that im out.

 

[reed b.]

Rusty, Thanks for your input. It took me back a few years- you know, before vehicle computers! I had thought about a clogged cat and have already separated them at the rear from the exhaust pipe and was able to look inside all the way up to the oxygen sensor. So I'd say no problem there. However, back to the gauge. It is sitting at only 13-14 " though it does drop a bit when revved and go up for a second when throttle is closed again. So low on vacuum. I will be checking all the hoses though I can't say I hear the typical sounds associated with a leak. Again, all the input is helpful. And appreciated.

 

[reed b.]

A gasoline engine will lose 3% of its power for every 1,000ft of elevation
So if you are at 4,000ft you're already at a 12% loss of power, and that's minimum, I would guess 15% would be more likely, as loss % increases over 3,000ft
After warm up check exhaust for Rich smell that would indicate an issue with air/fuel mix of course, and contrary to what many think Rich is bad in this situation, less power and low MPG

Find your vacuum gauge
At 4,000ft it shouldn't be lower than 16"

MAP can be tested with a Volt/ohm meter with a Hz setting, graph here: https://www.aa1car.com/library/map_sensor_ford.gif
The 2 outside wires are 5v and ground, test those first, key on
Center wire will have the Hz frequency signal the computer sees

Check key on/engine off Hz, at sea level it should be 159 Hz, at 5,000ft elevation 144 Hz, so 4,000ft should be 147 Hz
The computer gets this with key on to adjust for elevation

 

[reed b.]

Ron . Thanks for the extra education ! I am only seeing a steady 13-14". And now I've seen how to test the MAP which was one of the next steps. My thanks indeed.

 

[reed b.]

A gasoline engine will lose 3% of its power for every 1,000ft of elevation
So if you are at 4,000ft you're already at a 12% loss of power, and that's minimum, I would guess 15% would be more likely, as loss % increases over 3,000ft
After warm up check exhaust for Rich smell that would indicate an issue with air/fuel mix of course, and contrary to what many think Rich is bad in this situation, less power and low MPG

Find your vacuum gauge
At 4,000ft it shouldn't be lower than 16"

MAP can be tested with a Volt/ohm meter with a Hz setting, graph here: https://www.aa1car.com/library/map_sensor_ford.gif
The 2 outside wires are 5v and ground, test those first, key on
Center wire will have the Hz frequency signal the computer sees

Check key on/engine off Hz, at sea level it should be 159 Hz, at 5,000ft elevation 144 Hz, so 4,000ft should be 147 Hz
The computer gets this with key on to adjust for elevation

 

[reed b.]

I just checked and my dvm does have a Hz function, though I will need to learn to use it first! Again my thanks

 

[gaz]

reed,

On my stock 2.9L with headers, exhaust and chipped it fluttered with 27 vacuum @ 100' above sea level. So that is where I set the timing and it ran like a BEAST!