Engine/Transmission (1994 - 1998) sudden fuel mileage drop

[amillstream]

My brother ran his 97 out of fuel the other day and since then is getting 4-5 mpg less. He was getting 18-19mpg and is now getting 13-14 mpg. He has checked the fuel sediment screen, changed fuel filter, made sure the spring in bango fitting on return side of pump wasn't broke or jumped sideways. Any other ideas on what went wrong?

 

[SBrandon]

possible air trapped in the pump? bleed all injector lines and run another tank of fuel through it.

 

[JGheen]

That's weird..... I had run mine out of fuel about 6 months ago and I still get the same mileage..... that I know of. All I did was get more fuel, prime the pump and filter and it fired right up after about 2 cranks. I guess it depends on the situation that one would have to bleed out the injector lines... . but try it anyway, that could be the issue, not sure.

 

[amillstream]

He has ran quite a bit of fuel (at least 10 tanks) since this happened so we are assuming there is no air left in it. Could something have happened to his injection pump when he ran it out or maybe not even related to running out of fuel? It is running a little rough also but not bad. Any ideas? He put a fuel plate in but that was after he noticed the poor fuel milage. Any more ideas appreciated! Thanks

 

[jimk]

Originally posted by amillstream

My brother ran his 97 out of fuel the other day and since then is getting 4-5 mpg less. He was getting 18-19mpg and is now getting 13-14 mpg. He has checked the fuel sediment screen, changed fuel filter, made sure the spring in bango fitting on return side of pump wasn't broke or jumped sideways. Any other ideas on what went wrong?

Timing can effect mileage, I would check fuel pressure, clamps on the innercooler lines, does the truck miss? injector problem. Try the fuel pressure first. good luck jim

 

[bmoeller]

Check the air filter?

 

[Got Smoke?]

DEFINATELY check intercooler clamps. I had a mileage problem and it turned out to be a swollen intercooler boot. Checked the rest of the clamps and they were all a little loose.