1990 7.3 idi
 

First I would like to say Hello to all, I am new here and will try not to bombard ya'll with a million questions. I recently traded a suburban with a 6.2 idi for a for dually with a 7.3 idi... they seem like 2 different worlds for sure. Well i never could get the 7.3 to run, the kid i got it from said the oil cooled leaked and he regasketed the engine, i tried and tried to get it to start and never could, i filled the thing with coolant, plugged in the block heater tried to start it...nope...checked the oil and had half a stick of chocolate milk... so i am going to pull it and rebuild it and thats where my questions start... is it safe to bore it .010 over, can the cranks be turned in theses engines...say .010 over. I know with my 6.2 turning the crank was out of the question. and the heads...i am going to have a valve job done on them, does porting them (gasket matching) do anything in the way of helping performance. I do plan on turbo but not right yet. the engine is going to cost enough to build. are the head bolts reusable.. on my 6.2 they were tty bolts and had to be thrown away. I was going to fab the up pipes and manifold for the turbo myself, would a wastegated turbo from a gm 6.5 work on it... i had one on the 6.2 and it easily spun up 12lbs boost, i had a turbomaster controller on it, i think i could have gotten 20 if i just wired the wastegate shut....boooooooooom. i am not i am not going to be hauling 40 ft trailers but i would like to get some respectable power out of it while i have it torn down and if anyone can give me any suggestions that would be wounderful.

https://www.ford-trucks.com/forums/1...3-rebuild.html

That entire post is what i went through when i asked bout rebuilding the 7.3. Its up to you on what you do in the end. But these guys told me what to do and what not to do with the 7.3, dont bore it out because the 7.3 is a bored out 6.9 and therefore has thinner cylinder walls and is susceptatable to cavitation. There are examples of this in this post. If you resleeve it they dont hold very well unless you find somewhere for the new sleeve to sit on a lip of some sort so you dont have them sinking. There are a lot of dangers for rebuilding a 7.3, these engines have a very high compression rating and the thinner cylinder walls from an overbore will crack the block and you will be out an engine. If your going to tear it apart, read through my post and then ask questions from there, if you have any other questions just ask.

I am hopeing that after a good cleaning and fluxin that i have no cav issues with the block, and the cylinders are still in good enough shape to hone and re ring, this is after a good inspection of the pistons of course. i have read alot of good and alot of bad about these engines

These Engines are known for thier reliability and extremely long life, granted without serious modifications to it there is no way for it to keep up with the modern PSDs, however they can keep up with the early ones. The 6.9 is the more reliable of the 6.9/7.3 blocks because of the thicker cylinder walls.

If your just going to hone and rereing the engine you could probably get away with it. Still, be careful. One screwup and your gonna end up resleeving it at the worst or rehoning it at the least. At the very least if you see any potential problems with any of the pistons, replace them. Im just being the devil's advocate here and following Murphy's Law #64: What can go wrong, Will go wrong.

ok i got it ......but
 

i see that the 7.3 was maybe a bit misguided in just boring out a 6.9 .111, thats nuts to do to any block, so i am going to procure a 6.9 block and punch 'er out .060, i feel that i should get a good displacement and a meaty block. I found some Keith Black 19.5-1 comp pistons, i do plan on turbo charging this dude and i am a fabricator/plant maint at a foundry... so i am going to fab the pipes from the exhaust manifolds up to mount a turbo...has anyone ever experimented with a turbo off of a gm 6.5... i had one on my 6.2 n/a and they will put out alot of boost, they are wastegated and there are alot out there and they can be bought cheaply, the problem with the 7.3 idi turbos is...there aint that many out there and gm made the 6.5 idi turbo for about 10 years before going to the dirtymax, just a thoughtlet me know what ya'll think

ok here is an update....i found that the oil cooler was leaking...i rebuilt it...it dont leak no more...i tested my glow plugs....all work good....i put a new injection pump on it and injectors, 2 new 925cca batteries and and new starter.... still wont start, i am getting smoke out of the oil fill and i have the drivers side valve cover off and i am getting smoke thorough it , but thats all i am getting smoke....i rechecked the ip timeing and it is right one the marks.... i am almost tired of throwing money at it anyone got any suggestions?

Have you done a fuel pressure and flow ot the schrader valve on the fuel filter? Tere should be 5-7 lbs. and the flow should be 1/3 pint in 30 seconds of cranking. Do you have power to the wire on the front (closest to radiator) post on the injector pump?
Some times when replacing the IP it takes some time to get all the air out of the pump.
I hope you didn't remove the timing gear cover when you replaced the IP. It is really easy to get it way out of time if the cover and gear was removed.

i quit for the night but i think it is getting closer, sounds like it is hitting over on one or two cyls....yes i had the whole front cover and timing cover off all marks are where they are supposed to be

take some pics :-)

ITS ALIVE....finally i got her to start up....engine sounds pretty good but when i rev it up a little it bellows white smoke. and it smells like fuel smoke, i am hopeing that after i get the radiator back in it to where i can let it run this will clear up, maybe it has crap in the ip from the rebuiling process, i bought a U-Haul rebuit ip and pensacola injectors

does anyone have any pics of the front of their 7.3.....i took the brackets that hold the power steerin pump and ac compressor off months ago and cant figure out how they go back on....a picture would be appreciated

I do send me your email and I will send you the pics I have on my Blackberry here is my email address vfelix702@live.com

thanks i got it figured out, i read some post somewhere about a smoke screw on the u haul pumps, can someone tell me where it is, i am getting alot of fuel smoke when i rev up the engine, a whiteinsh blue smoke that smells like unburnt fuel and whick way do i turn the pump to advance the timing....to the passanger or drivers side

ok i got 1 more question, i got the engine running good and put the drive shaft back in it, put it in gear and nothing no forward or reverse only neutral, i was told that if the tach dont work neither will the tranny, the od light on the dash wont do anything when i push it, it is on, but dim, and my tach isnt working

one other question i have on the transmission.....should it be pumping fluid through the cooler lines regaurdless of the lectronics associated with it, mine isnt, i am afraid i have a bad tranny