Always runs best just before it blows up.

Discussion in 'The "Other" Bench' started by Briz, Mar 28, 2021.

  1. Briz

    Briz Platinum Level Contributor

    NO nothing has blowed up, yet! But Ive heard it said and experienced it once with a 200hp outboard. What got me to thinking about his is the fact that my old F250 has been getting better mileage consistently over the last 20,000 miles. Really she has always got 12-15 mpg empty. Then it started getting that while towing and even better as time miles has rolled on. Last road trip i took to get the Skyhawk I pulled a 83 3/4 ton Sq body cheby truck up to Michigan before I skipped over to Ohio to meet with Denny. It got 15-17 with that big ass truck on the trailer and 16-17 with the Hawk onboard weighing next to nothing. Today I went 2.5 hours south to pick up some parts and left with 3/4 tank . Thinking I'd have to fill up before heading home. Im nearly back to the house and the trucks gone 417 miles on that tank with a 1/4 showing on the gauge. Thinking its gotta be broke. Nope! stopped to fill up and it took 21 gals on a 28 gal tank. Math says just under 20MPG. Shes got 284K miles on the 7.3. Only reg maintenance , couple of fuel pumps , couple alts and I replaced the turbo at 160 just because. Anyway now Im thinking shes got a nasty surprise in store for me.. I really hope not with the Nationals trip coming up soon.
     
    70skylark350 and Dano like this.
  2. Quick Buick

    Quick Buick Arlington Wa

    That's called improves with age.....
     
  3. JESUPERCAT

    JESUPERCAT No Slow Boat

    Briz my 02 7.3 F250 3.55 gears is over 420,000 miles. Replaced injectors and turbo 250,000 miles ago. Mileage is 20/21 mpg empty and 13 to 15 mpg loaded.
     
  4. Quick Buick

    Quick Buick Arlington Wa

    Meantime thats damd good for 7.3.... Whats happening is your at optimum spray from the injectors. With use the very very very fine nozzle enlarge themselves with the fuel going though them... thats why you never replace just one or two injectors.

    Nice thing is yours and mine 12v are cheap..... This common rail stuff 1K each...
     
  5. Briz

    Briz Platinum Level Contributor

    Now that ya mention it I have replaced several injectors over the years. probably 6 and them jokers were not cheap. Like 350$ each
     
  6. Quick Buick

    Quick Buick Arlington Wa

    Thats why Im keeping my 93 & 95 12 valves. Under 100 bucks for new bosch injectors @ rock auto.......
     
    Dano likes this.
  7. buicksWILD

    buicksWILD Well-Known Member

    Thats why I chase cougars and im not talking about cats either.
     
    72gs4spd, Dano, Briz and 2 others like this.
  8. JESUPERCAT

    JESUPERCAT No Slow Boat

    2002 7.3. $900.oo for 8 injectors plus core through a friends company
     
    docgsx likes this.
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  10. Briz

    Briz Platinum Level Contributor

    As I got older and things quit functioning like it used to the whole cougar thing started to make more since to me. now I get it.
     
    Waterboy and buicksWILD like this.
  11. Briz

    Briz Platinum Level Contributor

    Couple weeks ago the truck started hard. Sort of diesel'd for a min then settled down and ran normal. Headed out to the dump and it died about 1/2 mile from the house. Like it ran outta fuel.. Got it fired back up and limped home. changed the filter and fired her up then continued on my way, no problems. Later that day we went out again and the same thing happened in the same spot. Got it home and parked it.. Pondered on it a few days, replaced the electric pusher pump just cause its easy and cheap. Had gone through 3 of those over the years. but that wasnt the problem. Then the light bulb came on above my head.. Oil pressure fires the injectors. Pulled the dip stick and it was dry. 6 qts later and its on add one but the truck is running fine again except now I know its burning oil. less than a thousand miles and Im putting oil in again. Its coming out the exhaust. I can see and smell it when I fire it and rev the engine. Dont know whats changed but maybe thats why its getting better millage. Oil injection into the cylinders.
     
  12. JESUPERCAT

    JESUPERCAT No Slow Boat

    Turbo seal may be bad. Check the air tube's for oil or if real bad empty the intercooler:eek:.
    Make sure your air filter is good also as this will cause some oil and fuel issues also.
    If you need to get a turbo or other 7.3 parts give me a shout and I'll send you a link for a good source
     
  13. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    Pull the boots and exhaust off the turbo and look for oil. Its fairly common for oil to pass through the turbo. Thats a high pressure oil feed and if there is a seal failure it can use oil like crazy and often times not have any effect on the way it runs
     
  14. Dano

    Dano Platinum Level Contributor

    Wish I could say the same for my '92 7.3 IDI. Not sure if it needs injectors (probably), a pump (supposed to change them & injectors together) &/or valve guides. Not really my desire to dive into it all myself either but might have to.
     
  15. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    I had a cool car hauler 2000 E-450 that had the 7.3 turbo, it was amazing and very good on fuel!
     
  16. Briz

    Briz Platinum Level Contributor

    50,000 + miles ago I rebuilt the turbo and used the ceramic seals along with something called a wild weasel wheel that was supposed to spool up faster but in reality just made more noise. So Im not really thinking its a problem with the turbo. Not gonna rule it out either. Will pull the exhaust side off and have a look. Another possibility is an injector o ring or 2.
     
  17. Briz

    Briz Platinum Level Contributor

    After waiting over 4 weeks on a list to get into a local shop the truck is in their hands. Dropped it off on Weds night and was supposed to get it back Friday. stopped in Fri afternoon and 1/2 the injectors were out and the mechanic said he didnt see any issues with those O rings. If the other side is good he wants to pull the heads and re do the cups. Gave the go ahead for that and while in there they can check the side play on the pistons. I know it has some blow bi. If its bad I'll just get a crate engine installed. There was some oil on the intake side of the turbo.
     
  18. 70skylark350

    70skylark350 Well-Known Member

    She’s just finally broken in
     
  19. 87GN_70GS

    87GN_70GS Well-Known Member

    My dyno guy is 80 years young. He's been in the business for 50 years. His experience is the same. They just keep running better til they blow up. He has countless stories
     
    Max Damage likes this.
  20. Briz

    Briz Platinum Level Contributor

    Stopped by the shop yesterday afternoon. The truck cab is up on the lift with the frame on the floor. Heads are off. L bank looks ok but theres a lot of oil in the exhaust on the R bank. Cylinders look good. Still have cross hatch showing and no real side to side play. Dont mean the oil rings are not bad. Heads are going out today to get checked and repaired if needed. Going to replace the body mounts and the oil cooler while in there.. Had no idea the cooler was mounted to the engine under the L Ex manifold. While im in there why not. Any suggestions on a supplier for the body mounts? Do not want poly.
     

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