[Gjc.38]

I’ve got a 1995 f250 with a 5 speed and today when I reached about 1500rpm the truck would make a noise that almost sounded like an engine brake and the truck lost a lot of power. This occurred both when I accelerated and let off the gas and stopped when I got it above 2000rpm. Any insight on what this could be would be much appreciated.

 

[Patrick Feeley]

Could be your Exhaust Back Pressure Valve (EBPV, the butterfly valve on the turbo's exhaust outlet) closing. You can try disconnecting the actuator solenoid and see if it helps. Look for a 2-wire weatherpack-type connector down by the base of the turbo on the driver's side. The valve is supposed to be for faster engine warmup, but it's really not that helpful in that regard. Cheers!

 

[Steve83]

Does unplugging the EBV set any fault codes or turn on the CEL?

 

[Patrick Feeley]

It didn't set the CEL on my 94 when I modified the pedestal and deleted the valve. I also don't remember any codes being stored. I think the 97's (at least California models) will set the CEL with the solenoid disconnected. In that case you can use a resistor in the connector to make the PCM think it's still connected (solenoid resistance is approx. 12.2Ω, use 10Ω 1-watt resistor). Cheers!

 

[1997VAstroker]

Both my 97's (not Cal models) have unplugged EBV for years with NO CEL.
Reason for unplugging them was because of the annoying loud flutter from the strait piped truck, then the stock truck truck started making noise too. No differences in warm up noticed on either truck

 

[Steve83]

Well, mine has been setting a trans slip fault very sporadically for a few months, but now, it has also begun to set an EBPV solenoid circuit fault, even though it's still plugged in and I can distinctly tell that it's working when the engine is cold, and opening as the engine warms up.

 

[Patrick Feeley]

Just in case you feel like running some tests, here are the Introduction and Pinpoint Tests for the EPR. When you get the circuit fault, is it a stored code without CEL or CEL with stored code? Cheers!

 

[Steve83]

I've only found the EBP fault code while clearing the slip code after the CEL comes on, so IDK if the EBP fault is there before the CEL comes on.