1994 f350 dual tanks 460 c.i.
Truck runs fine but dies at idle (blubbers at idle) if I am idling on rear tank and switch to front, truck will blubber (IDLE) worse and die.

Truck seams to run better on rear tank and idles better in drive, or reverse. Drives down the road fine. Cold start at 10 degrees farenheight is perfect, pops right off and goes to fast idle but will then slowly decrease until it idles very rough and might die.

When driving on the road ( 55 mph) on rear tank, truck will run fine. Switch to front tank (55mph) loses some power.

any help will be appreciated.


Doug

 

Fuel pressure? bad fpr..

 

I'm thinking the pump in the tank is shot or the sock is clogged and or fuel contaminated. the main pump on the frame works fine, the rear tank is ok, it seams the front tank has an issue, when you check it out changed the fuel filter to. quick test is to install a fuel pressure tester in the port on the fuel rail. Run it and swap tanks see if you loose pressure if not, must have some crap in the tank.

 

These trucks have in tank pumps. They stopped the frame pump in the 91-92 model junp

 

1990 was the first year with the high pressure in-tank pumps for gas powered F-series trucks.

 

Sounds like a bad fuel pump and or a dirt fuel filter. A bad fpr would have the same result on both tanks.

 

I think I am going to check fuel pressure and also change fuel filter (i have never changed it) if that does not work I will change IAC. remember this is pre obd2 and is not triggering a check engine light.

I will keep you updated may be a few days it is cold here in MInnesota

Doug

 

IAC is only for keeping an idle. That wouldn't have anything to do with a bog, especially at highways speeds or light throttle applied.

 

Fully aware this is an OBD-I truck. Many times there can be a stored code or issue that would cause a KOEO test failure code without having an active Check Engine Light.

 

OBD1 OR OBD2 doesn't matter they both have check engine lights.

 

My 97 cclb 460 e4od is an OBD1 truck

 

And everybody and their momma has argued with you about it ^^ lol

 

/\/\/\/\ yes sir they have/\/\/\/\/\. I was waiting for somebody to tell me I'm wrong again. Hey aren't you supposed to be working?

 

I am working lol. Aren't you? Haha. Just browsing the forums.

 

No I'm off the Boy's are out of school and the baby sitter fell thru.