1989 7.3 idi white smoke issue, stumped...

bigoilburner20

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wasnt there a cap or a sreen you could pull off and if it had metal shavings in it the pump was going bad I swear on youtube i thought there was a screen or something you could pull off maybe some one will chime in
 

icanfixall

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Removing the top cover of the injection pump was a known way to see if a plastic part was breaking up in th e pumps but I'm not sure if thats still correct or not. You would see small pieces of the part floating in the fuel. The pump does have a small screen on the fuel inlet but you really need to have the pump off the engine to check or clean it. there are some really smal parts in that area and there is an alignment pin that must be lined up or the pump wont fit together. As for reaching the bottom lines on the pump no.. You don't need to loosen them. Just the easy to reach 4 or 5 up top. Then move the pump and retighten them. Ford did make a special wrench to loosen or tighten the bottom lines on the pump. Ebay has them listed all the time too. The size of the nut on the hard lines is 5/8 inch.
 

crewd

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Back in it...

Did a compression test tonight
Cyl 1 - 360,355
Cyl 3 - 360,380
Cyl 5 - 375,380
Cyl 7 - 300,300
Cyl 2 - 390,380,360,360
Cyl 4 - 310,310
Cyl 6 - 310,320
Cyl 8 - 280,290,300,300

For the high and low cylinders, I went back to that cylinder and took a couple extra readings. The engine was cold, all glow plugs out, FSS disconnected. Basically I would crank over about 6-8 times for each cylinder, the compression usually reached its highest value by that point.

Is this healthy enough to bother with?

If so, I have a set of newly rebuilt injectors I will put in. But I will have to reuse one of the pumps. Probably the first pump (the one that was on the truck to begin with).
 

crewd

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Okay, went ahead and installed the rebuilt injectors and the first pump. Along with new orings, olives and return lines. No change in smoke, same behavior. While it is not timed, I'm going to rule out the injector and pump unless someone thinks otherwise.

I'm now focusing on the compression and valve train.

Some observations:
1) When I did the compression test, the #8 cyl and either #5 or 7 cyl (I forget which), when watching the compression guage, it would pump up to 100-200psi then fall to zero, but then pump back up and continue to build pressure until the final reading. Is this an indicator of sticking valves?

2) I changed the exhaust from a stack to a passenger dump in front of the rear wheel. I have oil dripping out where I have an exhaust leak at the flange at the end of the ypipe. Maybe at the rate of 1 drop on the ground every 5-10 seconds while it is running. I had a 4 inch puddle after 20 minutes or so. Looks like oil from the crankcase, dark black oil. Where is this coming from? Bad valve seals?

3) Watching the exhaust at the tailpipe, every so often I get a pop,pop or pop,pop,pop then it settles back down. When it pops, you see a white smoke puff, beyond the steady smoke I've been getting. Sticking valves here?

4) I double checked cracking each line to see if smoke would clear up. No change in smoke in any cylinder, and all caused engine to idle rougher.

Next step, pull valve covers?
 

icanfixall

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A compression gauge that drops off pressure is a bad gauge. If this is a horrible freight gauge then its shot no matter how new it is. This is the findings of several that have used the harbor frieght compression gauges. Sorry to say that too. A quality compression gauge will hold pressure till you manually drop it. Can't say much more to help you on this.
 

crewd

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Yes, you are right. It is HF junk. That was a dumb thought, I wasn't thinking. It happened on two cylinders making me think something was different.
 

crewd

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I wish people would report back no matter if it worked or not.
There's no answer because I didn't work on it any further. Had other projects and known good engines so I stopped working on this. Sorry.
 

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