95 Super Duty 7.3 Loses power when warm and during acceleration...
I purchased a 95 superduty with 240,000, 5 speed, on it a few months ago and Im not able to figure out the problem. I know it needs glow plugs and heres what I have done. The fuel tank was replaced and the sending unit, fuel filter and oil changed several times with motorcraft parts ond oil, vaccum pump replaced, batteries as well.It has no codes on the computer. It runs great and has alot of power when it is first started for 10 minutes or so, then when the temp gauge get to normal temp it suddenly has no power, it still goes but not fast and there is the smell of diesel coming from the exhaust whith a very light white smoke. It wont go away until the truck is shut off and restarted either driving or pulling over to stop. This will correct the problem for just a minute or so, then back to no power or acceleration. It kinda acts like a gas engine with a faulty electronic ignition. PLEASE HELP!!! The dealer says it needs new everything from injectors to fuel pump with a tag of 5,000 plus. If it needs all of this why does it RESET when you turn off the key then back on immediatly? Thanks!!!
maybeeeeeeee a fualty fuel pump or CPS. thats the only 2 things i would think could be going bad if you have no codes. but then why does it smell like fuel from exhaust??? means you not burning fuel. so that would mean no compression/combustion that would mean the truck would run like crap all the time.hmmmmmmmmm id say CPS.
i had the same problem and it was a chunk out of #7 piston. and believe it or not it would run good some time and white smoke other time very weird but true. i would also check for a faulty back pressure flap in turbo and make sure all your inj are tight i belive it is 40 inch lbs of torque also y your in there do a leak down test and check inj orings there a lot cheaper the most any thing else that could be worng. good luck hope that helps
Check and/or replace injector orings. With that many miles, if they are the original orings, they are probably shot and not sealing. Check and/or replace your under valve cover harnesses and valve cover harness connections, and while you are in there replace your glow pulgs. Check your Exhaust Back Pressure Value, it could be closing on you. Check the connections on you IDM and the wiring harness coupler for looseness. Check the entire wiring harness to the valve covers for burnt or melted spots.
I have replaced injector o rings and the back pressure valve. after doing this th a/c compressor decided to lock up. it has a new one of those too. but now one day later it diddnt want to start after several tries it ran then died. Its not the cps or fuel pump as i have checked. Im wondering about the idm???? would this may have been my problem from the start? what does it do exactly and where is a good cheap place to get one?is there a way to test it? thanks jeremy
Last edited by jcarr922; 06-07-2006 at 11:37 PM.
from the first problem you discribed i dont see it being the idm but its hard to tell with out seeing the truck. the idm is on drivers side fender lookes like a pcm. the only thing it does is control inj. and if bad will definitly cause it not to start. i had a cupple of them go bad on mine due to a bad engine harness which could be you problem also. but every time mine went bad it only ran on 4cyl or not at all. it sound to me like a bad icp or ipr which controls fuel icp is on drivers side head small 3 term sensor and if i had to guess the problem i would say ipr which is the small sensor on the bottom of the hpop which controll the oil pressue to run the inj. i need around 500 psi just to start shoul reach around 2500 psi at wot. very easy to check if you have a scaner if not then just replace it and see what happens its not to bad to do outher wise disconnect oil line from head and put on gage and see what oil psi is if not 500 or more it wont start and dont forget that it can reach 2500 so have a high pressure gage. hope that helps or narrows it down at least