1992 7.3l idi none turbo crew cab long box 4.10 gears 5 speed manual.

I have been pulling a 20 foot car trailor with three atv's on it for a while now, but the last two runs i made with it i noticed a major loss in power. With just a slight incline i am not able to hold 60 mph. Even if i down shift to 4th gear i still loose speed. I also noticed that a run that normaly used less than a half a tank of fuel now uses almost a full tank. I changed the fuel filter and it did not make any differance. I checked the fuel pressure and came up with 4 psi. I was told that 4 psi is in spec but on the low side.(still has a manual fuel pump) The only other place i can think to look is the injection pump, but i have no idea how to test it. I was told this engine was rebuilt before i bought the truck about 60,000 miles ago. The loss of power happened over one weeks time.
This truck should be able to pull more than that, correct?
How can i test the injection pump?
Any other ideas would be helpfull.

 

Check the air filter and fuel filter......... do you use any fuel additive. When you remove the fuel cap do you get a sucking sound. Any smoke seen and what color...

 

The air filter is fine, and i already replaced the fuel filter. I use anti gel. It's not poor fuel quality, i have ran 4 tanks through with the same problem. black smoke on hard accell. (it has always smoked under load)

 

have you checked the CDR valve behind the breather assembly lately? mine was nasty gunky and cleaned it. made difference.

speedrdr

 

Check that your e brake cables are all moving free- possibility that brake drag is causing performance issues?? Does your truck smoke at idle even when warm? Check for pressure build up in your tank, or a restricted return line system, these will affect your dynamic timing, causing balck smoke and poor milage. Restriction in the exhaust?

 

Do you have a picture of the CDR valve , I wan to clean mine . and what is a CDR

 

It's the tuna can shaped part bolted to the back of the intake, and clamped to a rubber coupling that connects to the valley cover/crankcase. Be carefull with the clamp and rubber coupling, they get brittle where the grommet attaches to the valley pan. (Crankcase Depression Regulator)-same as the PCV on a gasser. Good placed to start- should be cleaned every other oil change. soak in gas and slosh out until clean, do not use compressed air, check for broken diaphram, clear small vent hole on back of can, reinstall when completely dried out.

 

I will check the CDR valve. E brake cables are not hooked up, and the exhaust is not pluged.

 

I checked for this cdr valve, and it was not there. Someone must have removed it from this engine. Where could i get one of these? I checked with the parts stores and none of them have a part number for them.

 

i think this is a ford dealer item, but someone else may know better.

speedrdr

 

I am not convinced that this is my problem though, since the problems just started.

 

No, it's not your problem.The CDR is not going to effect performance to any significant degree.

I'd suggest checking the feul system. Look for any leaks.

Does it start OK?

 

This is the CDR.
Either Ford or International (Navistar) would be the place to get a CDR.

 

Is 3 psi of fuel pressure ok?
I have checked it over for fuel leaks a few times now and can not find any.
I still have the stock fuel pump on it, and i will change it to electric if it seems to be the cause of my problems.
I am just not shure about the injection pump?

 

What could i use for an electric fuel pump on this engine?