my dad has a 1990 f250 with a 302. it will run good sometimes. today i took it down the road and back which is about 4 miles and it run good so i let it set and idle for about 5 minutes the took it down the road again but after about 2 miles it is like its running out of fuel, it will idle fine but if you push the pedal down it will just about die, you can pump the pedal and it will try to go but you have to keep pumping it or let it idle or it will die. you can let it idle for a couple minutes and it will be good to go for a little while longer. i do know that it is full of gas. it has 35# fuel pressure at idle and goes up to 40 when you give it gas and we put a new filter on it. i dont know what else to try, you guys have any ideas

 

Check engine light on? Even if it's not, read the codes and post them if you find any.

 

Is this the fuel ressure when it is running good or when it is not?

 

catalytic converter may be plugged.

 

its the pressure when it is running good, i tried to check it when it runs bad but when you stop to check it and let it idle it runs fine
also it doesnt have any converters on it

 

i got codes 34 and 41

 

today i took it down the road and back which is about 4 miles

What speeds do you achieve in this run down the road?

If over 45 or so and based on what you've stated so far and codes you found stored, might want to check the egr valve, sticking open?

 

i was going probably 60 and how do i check the egr vavle

 

Aah I see you stated it idled fine, if the valve was stuck open it wouldn't idle very well.

No not the problem.

You gotta put a fuel pressure gauge on it so you can watch it while driving, see what it reads when the motor loses power.

 

Code 34: PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts.

You have an EVP (EGR valve position sensor) on your truck. This code is telling you that the EGR valve isn't always closing, which could be caused by two things: The valve itself could be sticky or have some carbon deposits stuck in it, preventing it from closing, or the vacuum switch that operates the EGR valve is faulty and applying vacuum constantly.

To check things out, pull the vacuum line off of the EGR valve with the engine idling. There should be no change in the way the engine runs, and there also should be no vacuum at the line. You may feel a small pulse, which is fine, but a strong vacuum is not. If you feel vacuum, or this changes the way the engine runs, then your vacuum switch is bad. (my memory sucks, but I'm pretty sure this is called an EVR)

If the switch checks out OK, try applying vacuum to the EGR valve with a vacuum pump, with the engine idling. This will open the EGR valve, and cause the engine to stumble. Release the vacuum, and the EGR should close, and the engine should go back to running fine. If it doesn't, your EGR valve either needs replacing or cleaning.


Code 41: HEGO sensor circuit indicates system lean (right side).


This is telling you that the O2 sensor is reading a lean condition, which may be caused by your EGR issues. I'd ignore this one for now, get the EGR issue squared away, clear the codes, and see if this code comes back.

 

i checked the egr and the vacuum switch and they both seem to be working like you say they should

 

I have found that spraying a little bit of wd 40 on the egr pintle and then moving it up and down a few times with a screwdriver works for a sticky egr valve.

 

Clean it, and try this. It may just get stuck occasionally.