1994 7.3 idi turbo bad mpg about 7-10

[19947.3idigogreen]

Hello everyone, im new to the site.

Need a Lil help with my truck. For why it's using so much fuel????

My truck is a 1994 Ford F350 reg cab long box 4x4 185,000 miles. 7.3 idi factory turbo. 4-10 gears 285/75/16.5 tires. Fuel pump 1/8 of a turn from being maxed. Turbo pushing 18-20 psi at full throttle. Egt at 700 at highway speeds.

The previous owner and when I first bought the truck I was getting about average 16-17 mpg %75 highway. Now it only 7-10 mpg no matter how I drive it. Since it started I replaced injectors (brand new Delphi code BB) timed pump to 9.5 degrees btdc. ( pulse method) new fuel filter.

Trucks starts rite up, runs a little rough/smokes like a B... For a lil but clears up pretty quick. (it's been highs here in Wisconsin of negative digits for temp).

Trucks runs exactly the same as before, runs extremely strong. smokes a Lil when you get on it but clears up quick when turbo spools. No fuel leaks!!!!

The only thing I can think is the pump is taking a ****....anyway to test it?

Or any other ideas what's wrong

 

[OLDBULL8]

Injectors. Have them pop tested.

 

[franklin2]

Are your parking brake cables sticking causing a slight drag on the rear brakes? It happens a lot on these trucks. After driving it see if the back wheels are hot.

 

[19947.3idigogreen]

I'll check that. Thanks. And I forgot to mention the truck is an auto E40D with a shift kit

 

[fordsrawesome]

Shift kit will hurt ya alot I had a 460 with a c6 shift kit and it got 5 lol cause it was always in way to low of a gear for power not MPG

 

[19947.3idigogreen]

It had the shift kit before when I was getting great mpg

 

[icanfixall]

How many miles are on the injection pump. We feel around 125,000 miles is what the pump and injecters are good for. Some get more and some get less miles on these items. Did the mpg drop after you timed it. If so might drop back to 9.0 degrees of advance and see what that does. Is the air filter clean. Not much else can cause bad fuel mileage but the pump mostly.

 

[19947.3idigogreen]

Pump is original that ik

 

[19947.3idigogreen]

Pump is original that I know of. Timing didn't change anything. Except ran a Lil better.. New air filter. What are my options for a new/reman pump. Also options for a performance pump

 

[NO_SPRK]

Lift pump.. intake restrictions. stock crimped Downpipe clogged with soot.. pump or injectors bad.

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[icanfixall]

Lift pump.. intake restrictions. stock crimped Downpipe clogged with soot.. pump or injectors bad.

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These contribute to bad fuel mileage but.. With 185,000 on the pump I'd say its pump time. The best known stock or built pump is from Mel at conestoga Diesel in Pa. He uses only quality Stanadyne parts and his warranty beats any on the market. He is world famous for the Moose pumps many of us use. they increase mpg along with hp and thats not heard of in the proformance world. You cna buy cheaper ebay pumps but your not getting a known quality rebuilt pump. Many have tried but they come back after spending 3 or 400 dollars only to end up paying again for the best from Mel. We get owners coming here all the time asking what to do because they got ripped off with a bad ebay cheap pump. We have learned that some ebay rebuilders only test the flow thru the pumps from cores. If they flow "close" to what they should they are painted and sold as a rebuilt pump. Thats simply a fraud selling something that never was as advertised. I realize money talks when its tuff to pay the price. Then its a take your chance on something clearly unknown and hope for the best. Sadly that usually never has a good outcome. A member here has gone thru three pump before getting a fairly good pump from an ebay seller. Another went thru 2 pumps including his own that died so its a decision to make.

 

[19947.3idigogreen]

It has an Aftermarket 3 in down pipe. I planning on replacing the lift pump soon.

I was looking at getting a moose pump and will most likely get one. Just don't which one?? I want more performance and plan on adding an intercooler soon.

Which one?

 

[icanfixall]

Only the builder of the Moose pump can truly advise you on which pump he makes will work best for you and your plans.

 

[79jasper]

OMEGA MOOSE!!!

Just kidding.

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[19947.3idigogreen]

Well checking back in again. Checked all brakes and there is no excess drag.

How could a bad lift pump cause poor fuel mileage?

Has anyone here ever rebuilt one of these injection pumps before? What actually causes it to use so much fuel?

I am looking to rebuild my injection pump by myself, Have done others before. Have the manual for tear down and rebuild. A fellow guy I work with has rebuilt multiple of these pumps before and knows how to do so with no calibration bench. Also knows how to tweak all the settings for more fuel/power

Thanks again