OK guys,

I want to know if I should replace my IP and subsequently injectors and timing by a professional. I get about 16.28MPG on the highway, I have 3.55s open, tires I will have to check on but stock or bigger for sure, not towing anything and I weigh about 110 or so. My beast is a 1991 with an E4OD and stock for the most part. I am planning a 4000 mile round trip and I want to get the most out of my mileage and I am hoping for 20MPG.

I figured my mileage by filling the front tank until I could see diesel fuel at the filler end, not just foam; driving on the highway for about 70 miles round trip and then filling back up to the same place. I took the miles and divided them by gallons used to refill and that is my estimate. I did have to get off a few exists, turn around and I bombed through an old county road but 95% of the trip was 60MPG at 1900 RPM with cruise set.

I am seeing about 10MPG in the city with a fair amount of idling. The traffic is 0-50, stop, 0-50 again, repeat for every stoplight I hit. I rarely get up on it. The tranny shifts into third around 2500RPM if I back it off at the right time otherwise I am looking at about 2800RPM.

If I nail her to the floor, I get a trail of brown smoke until I am in 3rd gear or so. I also get a pretty good report between 2800 and 3500 RPM. It sounds like a single injector is banging. It sounds cool as hell but I am more interested in MPG. My damn muffler-back fell off today so I have to have a shop weld that SOB back on before I can accurately record the sound. The PO (before the dealer) was a high school kid and it looks like he used some exhaust clamps on the pipe and got it all bent out of shape so it doesn't fit up right. Some clown cut off the hanger and hanger mount for no reason. I don't have a welder right now, so I gotta pay someone to do it.

 

 

I am pretty sure that is the original IP and injectors with 150K+ on them. I could be wrong, though.

 

Here's a tip for anyone trying to view the pictures. Hold down CTRL and SHIFT and press the - button up by the backspace key. That will zoom out and the pictures are very easy to look at. BEFORE YOU DO THAT and you can't read the screen again (LOL) you just press the + button to zoom in again.

Any ideas of how many miles are on the IP and truck?
The pictures aren't a good way to tell if the IP is on it's last leg.
The best indiator is mileage...apparetnly the magic number is 100k miles. After 100k it starts to go downhill on efficiency.

Your mileage is decent. I get around that when i drive normally with my 4 speed manual. I've gotten higher if I baby it and drive as if there is an egg between my foot and the go-pedal, but 16 is about my average when driving normally.

 

Is there some good instructions on replacing the I/P with pics on this forum?
I want to change I/P, injectors, return lines and glow plugs before a trip to Montana this November. Truck has 128K and never had the I/P replaced

 

The truck shows about 54K but it has most likely rolled over at least once. The purpose of the pictures is to let people see the outside of the pump to help determine if it is original and possibly having 150K on it or if it was replaced at one point and has less than that.

 

I don't know any thread off the top of my head that has pictures. But it's not as hard as you may think. I learned how to wrench on my '65 F350's 352 FE and our Jeep CJ 258 Inline 6...and I think working on this IDI is easier than the FE (which says something, since the FE is stupid simple also) and the IDI is easier than the miles of vacuum hose on the 258.

Here's a link where there has been some recent IP discussion: https://www.ford-trucks.com/forums/1...al-for-ip.html
This may also benefit the original poster, so I'll run thru the process here.

To remove the Injection Pump, you'll need a 5/8" wrench for the steel injector lines. Loosen the steel nuts holding the steel injector lines to each injector.
At this point, some will leave the injector lines on the IP and remove the unit like an octopus. I did that once and had poor results getting it out the truck...so now I take some maskign tape and number each line with the corresponding cylinder. I also have a piece of paper that I covered in clear packing tape that illustrates where each cylinder goes on the IP. It's not the end of the world if you don't label them, since each line can only go in it's correct place. Labeling just takes a few minutes of guesswork out of the equation.
If we continue by assuming the steel lines were removed from the injectors and the pump, it gets a little easier. So pull them off the pump.
On the front of the IP gear housing, you'll have either an oil filler neck or a plate. My 6.9 has an oil fill neck. Remove the 2 bolts you see, then pull the neck or plate off.
Underneath the neck or plate, you'll see a gear with (3) 5/16" 12-point bolts. Remove those 3 bolts using either a 12-point closed wrench or a socket.
Now, look on the engine side of the IP. There are 3 nuts holding the IP to the housing. 9/16" nuts as I recall. Pull those off.
EDIT: Forgot, you'll need to remove the throttle cable. Use a flat screwdriver and get the stupid little metal clip off the throttle arm. It's easy, just a pain sometimes.
Now, the pump will pull right off.

For the Injectors, 1" deep well socket does the trick. If you suspect it's been a while since replacement...start soaking with PB Blaster! The carbon build-up can be a pain sometimes. There's a guy here, LCAM, who had a tough time and the injectors actually unscrewed on him...leaving the nozzle tip down int he injector bore still. Do yourself a favor and give each injector plenty of PB blaster.

For the return lines, pull them off...no special way to do it. But try to leave each bank together...just so it's easier to create the new returns. You can lay each bank of caps/line down on the bench. Then pick out the new corresponding caps from the kit and cut the new fuel hose to the same length. You'll understand once you get to that point.

Glow plugs...plan on spraying them with PB Blaster every day for a while before you plan to do this job. They're easiest to do when the steel injector lines are out of the way. There are a lot of threads here on the forum describing how to do those. I think it's a 3/8" deep well socket if I recall... But do give them plenty of PB Blaster...just in case they are swollen. If the tips break off, you're in for a real headache! Either trying to shoot compressed air in the glow plug hole and using a shop vac in the injector hole...or pulling the head off the engine to retreive the stupid tip.

Here's the order I would do the job.
For 2 weeks prior to the job, spray the glow plugs and injectors with a lot of PB Blaster once or twice a day.
Pull the IP and fuel lines.
Pull the injectors.
Pull the Glow plugs.
Install the new glow plugs.
Installt he new Injectors.
Install the new IP.
Insall the steel injector lines.
Done.

Oops, I totally read right past your post indicating the mileage.
The return line and clamp look fairly new...don't know how new, but definetly not 150k miles old.
Your pump looks cleaner than mine, and mine's only got 30k. How often is the engine washed?
It looks similar to the pumps I've pulled of my own engine and my other 2 spare engines...all with unknown mileage.
Judging by your fuel milage, I think you're still in good shape.
Does it start easily? Any dead spots? Does it ever run funny?

Re-edit: If you're planning a 4k mile trip soon, you might as well replace everything so you know you're all good to go for many many more miles to come after your trip.

 

You should defntly be getng ome better mpg than what your seeing. I have a 2wd with the E4od nd get about 18 city and 2 highway. truck is bone stock with texception of a sraight exhaust. Im thinking the PO being a young guy turned up the IP pump. The black smoke when acc. and shiftin leads me to think is.

 

I didn't think of that. The soup bowl has been cut out as well, so maybe he did dink with the IP. It doesn't seem like there is any more power than the other IDIs I have driven but that doesn't mean it's not turned up anyway.

I only get the smoke when I stomp on it from a stop. It doesn't smoke much when I do it but I can see a light trail. It won't do it if I stomp it while up to speed.

 

More smoke doesn aways mean more power. Theres a few guys around me who I bet even with their urned up IP's. Not smoking while at speed culd just mean the engine is at higher rpm uses the bit exra fuel. Iv never been ableto make mine smoke even with OD off and stompig on it from dead stop and Im bone stock engine wise.

 

The return lines and caps have been replaced recently, I think 2009 according to the documents I found. I'm not sure if the engine has been washed but I know I never have done it. I don't notice any dead spots in acceleration.

Every MPG counts
4K trip 16MPG = $1000
4K trip 17MPG = $941.17
4K trip 20MPG = $800
Assuming diesel is $4/gallon and the MPG is the same the whole trip. The IP and injectors almost pay for themselves in just one trip if MPG goes up to 20 or above.

 

The $200 savings would be awesome for sure!
What are the specs on your truck?
It's a 91 7.3 with an E4OD
Regular cab, crew? 4x4?

I don't know that you'll see that large of an increase with the fresh IP and Injectors...
Things like opening up the exhaust into a bigger true dual system and getting more air into the engine will definetly get you some good results.
I seem to remember Warozz reporting a 1 or 2 MPG increase with larger exhaust and a ram air intake.
If you cut the exhaust Y-Pipe and clamp on some 2-1/4" to 2-1/2" adapters and then get it into a 3" system, you'd be in good shape.

Also, you do realize that you'll need to either purchase new Viton O-rings or a new injector install kit. Your O-Rings won't re-seal. You could re-use your caps and lines and just buy some new Viton o-rings.

 

I have a 1991 F250 E4OD 2WD Supercab. It is stock as far as I know. The PO put an aluminum dryer hose in place of the intake tube and it is routed to the driver's side of the radiator mount. I'm not sure what all that is about but I don't see a reason to fiddle with it. The exhaust is stock except for a (Magnaflow - I think that is what it is) muffler. I would like to do a straight pipe but I don't think it will be legal because I think all automobiles here have to have a noise muffling device attached. How much would it cost to have a 3" system put on?

I do know about the O-rings. I would keep the caps and lines because they are fairly new.

 

eaton9999-
have basicly the same ruck as you so ou can definatly get some better mpg outa tha engine. Im unning some BFG Cmmercial T/A'sstock size. Maybe for thitrip get some less aggessive tires from a buddy or new ones if yor about to replace them. That could free up some rollig resistnce and proper psi inthem

 

If I replaced the IP and injectors, I would have it professionally timed, as well. I need to find a tire gauge that goes high enough. I think these trucks take about 70 PSI, right? I will have to take it to a gas station because I don't have an air compressor right now. Not sure what size tires I have but they say Hancook Dynapro IIRC. They are brand new.