Old truck - New owner. It needs some love.

[Ryan Cowper]

I just burned through my first tank of fuel on my 1989 f250 7.3 N\A M\T. So long as the Oracle is correct in suggesting that I have a 18.2 galon auxiliary tank - I'm gettin less than 9 mpg unloaded. 3\4 of this tank of fuel was highway miles @ 60 mph. Good lord I hope it gets better as I fix things up. With fuel prices the way they are, If this keeps up, I'm fixing to be out of money before I even get started. I'm going through things, trying to service what I can as I go. I have no experience working on diesel trucks and I got this truck to learn, so that's what I'm fit to do.

I can't find a service manual. I got the Haynes gas engine manual to tide me over with until I find a good one. I'm sure I'm not the first one to wonder why the Chilton's issued both a gas and gas\diesel repair manuals under the same #26664. There's gotta be something better anyhow... recommendations? Is there an online manual or does anyone have a digital manual they could send me?

I can tell already it's a good thing I'm single because I'm about to spend all of my time and money getting this old thing going. I started putting together a list of issues:

When I cycle the glow plugs in the morning, after the "wait to start" indicator turns off, my emergency brake and rear anitlock dash lights flash twice. Wait a few seccons and flash twice again. They don't actually flash all the way off, just dim and bright, dim and bright. They do it a few times and return to normal (well... the rear antilock stays on, but I hear thats "normal") Is the flashing just batteries kicking on to cycle the glow plugs or is it some sort of indicative flash?

I just changed the oil and it looks fine. I checked the front and rear diff. Rear was dark brown and in need of a change. However, the front was a very dark green color and there's some metal shavings in there too. Anybody got thoughts about that?

Fuel return lines, from end to end look like their made out of a garden soaker hose. Is it cheaper\better to piece together my own return line kit or buy one pre packed? Which kit do yall recommend? Links? I like cheap but I will spend money if it saves me time and headaches in the long run.

PO used autolites and I'm going to replace with ZD9's. Hopefully that goes well.

I want to tune down the injection. PO said her mechanic tuned it up for hauling her trailer. With only factory gauges to guide. Any tips on getting tuned back to spec? I can only find videos of folks tuning up I have to keep a real light foot or else a ********* cloud goes blowing all over that poor old lady in the crosswalk.

Additional things that need attention: Washer motor, power locks, RABS, brake pads, tie rods (all of em), ball joints (all of em), valvecover gaskets, door lock cylinders (missing key)....

Well, that was a mess of questions and a mess of issues to work through. Sure hope this beast is worth it.

 

[Oledirtypearl86]

So on an idi do fuel mileage is easy adjusted by the skinny pedel and kinda sounds like your IP timing might be a little retarded as far as your lights going crazy there is someone with more knowledge on here tjat can help you

 

[Ryan Cowper]

easy adjusted by the skinny pedel

Do you mean go easy on the petal? Because I drive this thing like it's a turtle.

 

[Oledirtypearl86]

Do you mean go easy on the petal? Because I drive this thing like it's a turtle.

Yes and that is also why I suggested your Injection timing being off that can affect your mileage a lot to I have a 86 F-350 with. 6.9 qnd towing my camp trailer in the mountains I can always count on at least 10mpg and the trailer weighs 9k loaded a good fuel system is key to efficency don't worry these old idis are great trucks and very reliable

 

[IDI_Journeyman]

For the injector return line kit you’d want a Delphi kit with some Viton O-rings. There are a few people on here that sell them, you can also get them online if you look. Better off spending the money once and being done with it.

I would put ZD9 glow plugs in as soon as you could, those cheap autolites are no good. I have been lucky and haven’t had a bad experience yet, but they can fail and seriously damage the engine! Having a push button switch for glow plugs also makes them last a lot longer, it’s easy to wire and removes a troublesome/expensive automatic system. Just don’t go over 10 seconds on the button.

I have a 85 F250 with a ATS kit on it and the most MPGs I got was 16-18 unloaded on the highway, it’s possible to get more just depends on your driving habits and how many hills you have where you live. Try some fuel additive and see how it effects the mileage, you might just need to clear the cobwebs out of the injection system.

Just take care of it and it will take care of you. these engines are simpler than you think and just require the correct parts and maintenance. A 7.3 IDIT has around the same output as a non inter-cooled VE pump 12 valve Cummins, it revs higher, is cheaper on the market and sounds a hell of alot better to me than a Cummins.

There are TONS of information about EVERYTHING you could ever think up on this website, you just gotta look it up or start a thread. Talk to people on here, you’ll find what your looking for eventually.

 

[chillman88]

First things first. I would get a new fuel filter, fill it with ATF (yes, automatic transmission fluid) dump a quart of Marvel Mystery Oil in the fuel tank, run it for about a minute and then shut it off and let it sit overnight. The ATF sitting in the fuel system over night will clean any gunk that has accumulated over the years inside the injection pump.

After that run it like you stole it to the highway and drive it for an hour to get everything warmed up real good.

Then I would look at adjusting your timing. You might want to turn the pump volume down but you won't know until you check timing first. Look at the timing registry and see if there's anyone near you with a meter. If not you'll have to play with it for a while to get it close.

 

[jayro88]

If you are NA and the pump was turned up and you are having to be careful about blowing black smoke I would turn the pump down. Problem is you don't know how much it was turned up, but you could start with 1 flat and then test it out. Timing it correctly ASAP would be a good idea also. If you don't know the age/mileage of your pump and injectors I would start saving for a replacement set. Just make sure you get them from a reputable place. There are a couple of good IDI vendors to use.

Like others have said, the first thing I would do is get rid of the Autolite GP's. It's not the fact that they burn out that is the bad part. They are known to swell up which makes removing them a huge pain, plus the tips can break off causing you to have to dig deep in the engine to fix it.

As far as your MPG, you should be able to get a lot better than that. Is yours a 4 speed or 5 speed? A lot of things can effect your mileage, but I would think you should get high teens to low 20's once you get things fixed up and if you drive it nice. For reference my '88 e250 with a c6/3.54's and an aux overdrive has gotten as high as 19mpg on hwy trips and usually will see around 16mpg with mixed driving during the summer. I get anywhere from 9-12mpg towing my 30' travel trailer. Winter time it usually drops 1-2mpg. With an old worn out IP and injectors I was getting in the 13mpg range mixed driving.

 

[austin92]

I just burned through my first tank of fuel on my 1989 f250 7.3 N\A M\T. So long as the Oracle is correct in suggesting that I have a 18.2 galon auxiliary tank - I'm gettin less than 9 mpg unloaded. 3\4 of this tank of fuel was highway miles @ 60 mph. Good lord I hope it gets better as I fix things up. With fuel prices the way they are, If this keeps up, I'm fixing to be out of money before I even get started. I'm going through things, trying to service what I can as I go. I have no experience working on diesel trucks and I got this truck to learn, so that's what I'm fit to do.

I can't find a service manual. I got the Haynes gas engine manual to tide me over with until I find a good one. I'm sure I'm not the first one to wonder why the Chilton's issued both a gas and gas\diesel repair manuals under the same #26664. There's gotta be something better anyhow... recommendations? Is there an online manual or does anyone have a digital manual they could send me?

I can tell already it's a good thing I'm single because I'm about to spend all of my time and money getting this old thing going. I started putting together a list of issues:

When I cycle the glow plugs in the morning, after the "wait to start" indicator turns off, my emergency brake and rear anitlock dash lights flash twice. Wait a few seccons and flash twice again. They don't actually flash all the way off, just dim and bright, dim and bright. They do it a few times and return to normal (well... the rear antilock stays on, but I hear thats "normal") Is the flashing just batteries kicking on to cycle the glow plugs or is it some sort of indicative flash?

I just changed the oil and it looks fine. I checked the front and rear diff. Rear was dark brown and in need of a change. However, the front was a very dark green color and there's some metal shavings in there too. Anybody got thoughts about that?

Fuel return lines, from end to end look like their made out of a garden soaker hose. Is it cheaper\better to piece together my own return line kit or buy one pre packed? Which kit do yall recommend? Links? I like cheap but I will spend money if it saves me time and headaches in the long run.

PO used autolites and I'm going to replace with ZD9's. Hopefully that goes well.

I want to tune down the injection. PO said her mechanic tuned it up for hauling her trailer. With only factory gauges to guide. Any tips on getting tuned back to spec? I can only find videos of folks tuning up I have to keep a real light foot or else a ********* cloud goes blowing all over that poor old lady in the crosswalk.

Additional things that need attention: Washer motor, power locks, RABS, brake pads, tie rods (all of em), ball joints (all of em), valvecover gaskets, door lock cylinders (missing key)....

Well, that was a mess of questions and a mess of issues to work through. Sure hope this beast is worth it.

Pretty sure these are 19 gallon tanks, average your fuel economy over a few tanks, avoid long idle times. My truck has 3.73s zf5 na and rough driving/towing won’t drop below 11, usually closer to 13-14. Easy driving is usually 17+. I BABIED It about 35 miles one day doing 55, no stops other than the second gas station and got 30.1 mpg. That was a test and not normal circumstances, I was simply trying to see what it was capable of.

If I had to guess on your brake and abs light, the glow plugs draw a lot of current and could be taking power from those bulbs. The on and off could be a bad glow plug relay. Does it click under the hood as the lights dim?

Metallic fluid in the diffs isn’t abnormal but “shavings” could indicate a serious problem or a fresh rebuild. With clean fluid, it could be either I’d assume. PO could be hiding or trying to “fix” an issue with the new fluid. I’d pop the cover and check things out visually and if you have a dial indicator with a magnetic base we can get a little more in depth

Don’t cheap out in return line kits. There’s differences in quality of the plastic caps and as already mentioned the viton orings. Grease them well before sliding over the injectors. My recommendations for a kit would be from Russ (typ4), Wes (Thewespaul), or Mel (agnem) all on here or Mel’s site conestoga diesel injection. Justin at r&d idi sells quality kits as well but isn’t a member here

Yes, get those autolites out ASAP. Spray them with penetrating oil, warm the engine for a few minutes and SLOWLY back them out. If they bind at all, more spray, back in then try again. I found my motorcraft glow plugs on eBay very reasonable.

If you found videos of turning the pump up you can turn it down. Try a flat or 2 towards the firewall. Go rip on it, a small puff after you take off and very faint trail at wot is about normal for a stock tuned pump. Thick black smoke is heat, don’t hold it there long with out a pyro. Too advanced timing makes excessive black smoke also, does it clatter real loud?




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[lotzagoodstuff]

Welcome to OB. All of the above postings are pointing you in the right direction.

Two additional things you should consider:

Forget about what you think the tank size is: if you fill any single tank, drive the truck and keep track of your mileage from that full tank, and then fill up in as much the same way as you "topped off" the first tank, you'll know how much fuel you burned. The stock fuel pickups are notorious for failing, so in most cases you will never burn a complete tank of fuel as some fuel is simply trapped when your "shower heads" break off.

Are your tires the stock size? The reason I ask is that this will make your odometer read less miles than you are driving, and taller tires general take more power (read fuel) to turn.

Lastly: are you running any kind of additive? The glow plugs are most important as Autolites can ruin your life pretty fast, but I would say that not running any additive in an IDI is a bad thing as you need the cetane as well as the lubricity to keep your pump alive. I would bet that you'll see a noted improvement in mileage with Power Service or Howe's additive.

Again, welcome aboard. Ask lots of questions and your old rig will benefit greatly.

 

[renjaminfrankln]

I have seen up to 19mpg unloaded with the truck in my signature. That is with 4.10's running about 2400rpm at 65mph. I average 17.5 combined, that is a number I am very sure of (my fuel sender does not work so I fill up via mileage and I do a calculation about every tank).


Get your timing set and turn the fuel down 1/8th of a turn at a time. You should get light black smoke under heavy acceleration at lower RPM's, otherwise it should run clean.

 

[Ryan Cowper]

A lot of responses today! It's going to take me a while to get back to all of them but I'll start with the direct questions you guys asked.

If I had to guess on your brake and abs light, the glow plugs draw a lot of current and could be taking power from those bulbs. The on and off could be a bad glow plug relay. Does it click under the hood as the lights dim?

Yes, there is a quiet click noise from under the hood as they dim. I assumed it was GP cycling.

Is yours a 4 speed or 5 speed?

5 speed.

Too advanced timing makes excessive black smoke also, does it clatter real loud?

Clatter? I wouldn't know what it's supposed to sound like, but yes. It has a very loud clack, clack when it first turns over on a cold start. After the engine kicks itself down - after a couple of minutes - the clacks quiet down considerably.

Forget about what you think the tank size is: if you fill any single tank, drive the truck and keep track of your mileage from that full tank, and then fill up in as much the same way as you "topped off" the first tank, you'll know how much fuel you burned. The stock fuel pickups are notorious for failing, so in most cases you will never burn a complete tank of fuel as some fuel is simply trapped when your "shower heads" break off.

I had considered that as a possibility. I guess we'll cross that bridge when we come to it.

Are your tires the stock size?

Just threw on a brand new set of 235\85 16 AT II's on the stock rims.

running any kind of additive?

No! I'll definitely be going to grab that today. How much goes in a tank?

I am working on swapping my radiator and doing a full flush before I get to anything else. I'm actually stuck at my mother's place without any damn my tools. I live waaaaaay out in the sticks and drove to town just to look for a truck on Craigslist. After getting this rig, I realized I better stick close to an autoyard and parts store until I address the most pressing of issues. Tool rentals are saving my butt.

Got a split on the upper tank seam on the way home from buying it. Long story short, I pulled one off of an 89 7.3 auto trans at the local autoyard, plugged the extra trans and heater core stubs with brass and today I pressure test and hopefully swap, and flush the heck out of the system (see my recent thread: Newbie intro and radiator questions). Sidenote - (lets not hijack the thread with this) The truck I pulled the rad from had a belt driven hydraulic pump attached where the A\C would normally sit and a custom hydraulic tank in the bed. They looked to be in great shape. It wasn't a dump bed, didn't look like they were using a plow. Maybe for a hydraulic lift? Tools? Wonder what it was used for. Anyhow, thanks everyone for all the quick responses. I'm sure happy to know y'all are here.

And just for the heck of it, for anyone who cares, here's a link my rock auto shopping cart. I'm filling it up with the parts I need. If anyone wants to double check my parts to make sure they're all going to fit\are good choices\or if you know of a better deal or option. http://www.rockauto.com/xx/cart/?cartid=c093a91e22d2da3e21a9203afa069563

Cheers!

 

[Ryan Cowper]

Timing it correctly ASAP would be a good idea also

Do I run any kind of serious risks driving with the timing pump not set correctly or is it just going to run like crap? It starts ok-ish on a cold start, after about 4 revolutions. Smokes black on the first puff and then white for about 3 minutes\around the same time the engine kicks down to a regular idle. It drives alright, no real hesitation. It might have a little bit of a miss, but... as I said I don't have much in the way of reference go off of in terms of what a well timed engine would run\look like.

 

[austin92]

The clatter in high idle and quieting down after it kicks off is normal. Sounds like timing is pretty close. If it’s a little off it won’t damage anything


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[Ryan Cowper]

@lotzagoodstuff I got some Howe's additive today while I was picking up my rad hoses and thermo. I might be crazy but it responded pretty quickly to that stuff, noticable pep and less black smoke. As per the label I doubled the dose and will do that for the next few thank fills.

@chillman88

get a new fuel filter, fill it with ATF (yes, automatic transmission fluid) dump a quart of Marvel Mystery Oil in the fuel tank, run it for about a minute and then shut it off and let it sit overnight. The ATF sitting in the fuel system over night will clean any gunk that has accumaccumu over the years inside the injection pump. After that run it like you stole it to the highway and drive it for an hour to get everything warmed up real good

Sounds like you've done this before. Would I add the quart of MMO to a full tank?

I also ordered the motorcraft glow plugs today and I plan to get them in ASAP.

 

[jayro88]

@lotzagoodstuff I got some Howe's additive today while I was picking up my rad hoses and thermo. I might be crazy but it responded pretty quickly to that stuff, noticable pep and less black smoke. As per the label I doubled the dose and will do that for the next few thank fills.

@chillman88
Sounds like you've done this before. Would I add the quart of MMO to a full tank?

I also ordered the motorcraft glow plugs today and I plan to get them in ASAP.

Not sure what all is in MMO, but I know tests were done and adding ashless 2-cycle to the fuel is supposed to be one of the best for added lubrication. I believe the ratio is 1oz per gallon. They have some pretty cheap at Walmart. Over dosing it won’t hurt anything either. These motor will run okay on a lot of different oils. Biggest thing if running other oils is the cleanliness of the oil.


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