Help Needed 1995 7.3 PS with low power when cold and slow acceleration

[mr brent]

I have a 1995 F350 with a 7.3 PS. I replaced the glow plugs and controllers, fuel filter, the four fuel hoses that slip onto the fuel filter and even checked all my turbo connections. I'm at a loss of what to do next. My truck cranks fine but will not take the fuel. I can hold the pedal to the floor but it still won't go above idle until it warms up. When it does start taking the fuel, it has very low power and struggles to move the truck. after a about 15 minutes of idling, I can drive the truck with only minimal power loss but the slow acceleration is still there. The truck runs great and has plenty of power once you hit the 45 to 50 mph range. Any idea's would be appreciated.

Brent

 

[94f450sd]

look at your turbo.on the compressor side(where the orange boot from the air cleaner is attached) there is a black electrical plug there.it has 2 wires unplug it and see how it runs.this is actually normal for our trucks cuz we have an exhaust back pressure valve that closes off the exhaust to force it to warm up faster.

 

[94f450sd]

click the below link.see the 2 wire plug on the bottom of the compressor side?thats what you will be disconnecting.it wont set a check engine light or anything and will be fine if you never plug it back in.only thing that will happen is when somebody puts a scaNNER ON IT IT will pop up a code for the EBPV not working but all will be fine.

turbo pictures from trucks photos on webshots

 

[mr brent]

Thanks, Ill unplug it in the morning. The truck is warm now from a trip to town. I forgot to mention that I have 296,000 miles on the truck. It's a crew cab 2wd dually. I use it to pull my goose neck horse trailer.

 

[94f450sd]

how long have you owned it?and if youve had it a while did it just start doing this? when was the last fuel filter change?what color was the filter and fuel in the housing?has it been gaining any oil?

 

[mr brent]

it's been doing this for about 7 months. I replaced the fuel filter when it first started and again about 2 months ago when I changed the oil. The fuel filter wasn't too bad and the fuel didn't have a strange color to it. I did notice a slight amount of water but I drained it. I had a guy tell me that I might need a new FPR but I don't know why that would be. any thoughts on that?

 

[Zookie400]

it sounds almost like you have a bad oil temp sensor, although without a scan tool i dont know as there is a way to check it. our engines are programmed to "not take the pedal" when the oil is cold. what you are describing is exactly what my truck does when its cold, however it needs to be really cold (30 or below) and when it warms up it runs perfect.

when you hit the throttle does it even change tone, or does it just totally ignore your request?

 

[mr brent]

I hold it to the floor with no response and after a minute or two it VERY SLOWLY starts to climb above idle. The truck runs better if it idles for about 15 minutes before driving. Any chance this oil temp sensor could be unplugged and causing this?? Or just a bad sensor in general?

The check engine light randomly comes on but then goes back off while driving. It's not common but does happen from time to time.

 

[strokin'_tatsch]

the oil temp sensor is an easy fix and is cheap if you want to try it just to knock that idea out of the question. they are like $30 from ford. i would unplug the EBPV just to make sure that's not the cause before anything else though..

check the fuel pressure at the shraeder valve at idle with a cheap tire pressure gauge, put a rag under the valve when you check it b/c some fuel will come out when you first press it in. let us know what the fuel pressure is.

 

[mr brent]

I unplugged the EBPV and noticed a big difference. The truck will move as soon as I fire it up now. The truck still lags and has less power than my non turbo 1993 model. After the truck gets rolling and the turbo spools up good, it runs like a raped ape. I'm going to replace the oil temp sensor and the CPS this weekend if I have a chance. We'll see where it goes from there. I can't complain, at almost 300k on it, I got my moneys worth and it's cheaper to repair than to buy a new one.

Thanks for your replies. I'll check fuel pressure and post an update after I replace the sensors.