How to check injectors?

[walleye guy]

I'm a newbie and am looking for some help. I'm not mechanical, so explain it to me like you would to your two year old! hahaha Anyways, I've been trying to get better fuel economy. Oh I have a 99 F-250 SD w/ 7.3 and 104k on it.

I'm just really frustrated because many of the people that I talk to that have the same truck are getting much better mpg than I am. On a trip unloaded and driving nice, I got 14 mpg... On my last trip pulling my boat, I got 10.5 mpg. I realize that I'm not driving a escort here but most are telling me that I should be getting 18 to 20 empty and 15 or so pulling. I don't know if people are BSing me or what?

My truck has the following things done to it. Superchips programmer, k and n cold air intake and aftermarket 4" exhaust. Also running synthetic and fuel supplements. 285 tires and stock is 265 if that matters and no lift. 4x4 and crew cab. Thats it!

I am wondering if I am having a injector problem because on my trip pulling my boat, I went back to stock on the forst part of the trip. It seemed like I did not have alot of power, especially going up not very steep or long hills. The truck would down shift like a gas truck when I was going up hills and I am only pulling for sure less than 5,000 lbs. Even when I'm running stock this truck shouldn't be like this. This is my first diesel so I have nothing to compare it to. Does this sound like an injector issue or any other ideas or suggestions would be greatly appreciated!!! How about checking the injectors. Can this be done with a scan machine or computer or does the motor need to be taken apart and actually look at them? Thanks

[vitalidle]

Originally Posted by walleye guy

I'm a newbie and am looking for some help. I'm not mechanical, so explain it to me like you would to your two year old! hahaha Anyways, I've been trying to get better fuel economy. Oh I have a 99 F-250 SD w/ 7.3 and 104k on it.

I'm just really frustrated because many of the people that I talk to that have the same truck are getting much better mpg than I am. On a trip unloaded and driving nice, I got 14 mpg... On my last trip pulling my boat, I got 10.5 mpg. I realize that I'm not driving a escort here but most are telling me that I should be getting 18 to 20 empty and 15 or so pulling. I don't know if people are BSing me or what?

My truck has the following things done to it. Superchips programmer, k and n cold air intake and aftermarket 4" exhaust. Also running synthetic and fuel supplements. 285 tires and stock is 265 if that matters and no lift. 4x4 and crew cab. Thats it!

I am wondering if I am having a injector problem because on my trip pulling my boat, I went back to stock on the forst part of the trip. It seemed like I did not have alot of power, especially going up not very steep or long hills. The truck would down shift like a gas truck when I was going up hills and I am only pulling for sure less than 5,000 lbs. Even when I'm running stock this truck shouldn't be like this. This is my first diesel so I have nothing to compare it to. Does this sound like an injector issue or any other ideas or suggestions would be greatly appreciated!!! How about checking the injectors. Can this be done with a scan machine or computer or does the motor need to be taken apart and actually look at them? Thanks

18-20 is pushing it with your truck. I average 17. You have oversize tires so you will have to factor in that on your mileage as your speedometer is off and so is your odometer. You can check the injectors with a buzz test to see if the electrical side is good and also a cylinder contribution test, but you will have to have someone with the right equipment do these tests. I think first you should make sure you getting your tank filled right up to the top everytime hand calculate and factor in the 285's Use a gps because your about 2 mph faster with the 285's then what your speedometer is showing and therefore you traveling more miles then what your odometer is showing.

[SCUFFY828]

i doubt very seriously that you have bad injectors , there are alot of things that can contribute to bad fuel mileage , i would get the codes checked , is maintenance up to par , get codes checked

[PSDfan99]

My truck has 315/75-16's (about 35's) and my speedo is EXACTLY dead on, so is my odometer. I have checked my speedometer several times against the poilce redar and it's right on, not even off by 1mph. I travel exactly 25.2 miles everyday one way to school, and the odometer is EXACTLY dead on. I have 3.73 gears and @ 70mph I'm at exactly 2,000 rpm's. I have not done any "recalibration" to compinsate for larger tires, so I guess I cant explain why my numbers are still perfect with 35's?

That being said, I would be greatly suprised if his 285's would throw his speedo and odometer off enough or at all to make his MPG seem low.

[vitalidle]

Yeah I can't explain why your bigger tires haven't changed you speedometer My 285's changed mine 1.5-2 mph at 60 mph according to my gps over my 265's.

[PSDfan99]

I would think that they would have a very significant change on my truck, but much to my suprise they dont.

[Striker]

Are your hubs locked in when your in 2wd?

[2005F250]

285's made my speedo dead on. Now I have 35's and it's off by 7mph at 70.

[f250ghost]

I went from 285's to 35's and my speedo is right on also. I was actually getting BETTER gas mileage after I put the bigger tires on...thats before my truck started running like S**T!!! What exactly do injectors affect? Some of you might know I've been having troubles with mine, running weird, jerking back, lack of power sometimes, etc...could it be in jectors? EGR? Torque Converter? Fuel pump? Clogged fuel line? It seems to be getting worse by the day...Let me know what fixes yours walleyguy!

[2005F250]

Originally Posted by f250ghost

I went from 285's to 35's and my speedo is right on also. I was actually getting BETTER gas mileage after I put the bigger tires on...thats before my truck started running like S**T!!! What exactly do injectors affect? Some of you might know I've been having troubles with mine, running weird, jerking back, lack of power sometimes, etc...could it be in jectors? EGR? Torque Converter? Fuel pump? Clogged fuel line? It seems to be getting worse by the day...Let me know what fixes yours walleyguy!

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