help needed badly

[wopster1]

i have a v1502 4cyl diesel it runs horrible. when idling has blue smoke from cyl1 & intermittenly from 3. i have done every thing imaginable new rings & cyl sleeves rebuilt injectors & pump has 300psi compression across the board
. when accelerated smoke comes from all 4 cyls. misses& sputters. at my whits end. i am a licenced tech on automotive but this has me stumped any ideas anyone. thanks

 

[bruceatlam]

Fuel filter and new fuel ---------------

 

[kuboman]

i have a v1502 4cyl diesel it runs horrible. when idling has blue smoke from cyl1 & intermittenly from 3. i have done every thing imaginable new rings & cyl sleeves rebuilt injectors & pump has 300psi compression across the board
. when accelerated smoke comes from all 4 cyls. misses& sputters. at my whits end. i am a licenced tech on automotive but this has me stumped any ideas anyone. thanks

Should not the compression be up around 450psi? Would maybe recheck the timing too.

 

[wopster1]

fuel is new as is filter.not sure what proper compression for this engine.however my b7500 manual says 325-450psi. have checked cam & injector timing as per my other manual.is it possible the engine needs to be worked hard to break rings in

 

[kuboman]

fuel is new as is filter.not sure what proper compression for this engine.however my b7500 manual says 325-450psi. have checked cam & injector timing as per my other manual.is it possible the engine needs to be worked hard to break rings in

Being on or below the bottom end for compression I would say that the low compression could make it run that poor. If you could put it on a good solid load for several hours it would likely help but unless it has had a lot of idling even new rings should seal better than that.

 

[fj40dave]

The way it reads above, you've rebuilt it?

New rings?

Is it possible the rings arn't set right/oriented on the pistons allowing blow-by and excessive smoking during a load?

I wouldn't run it hard to set the rings....the motor I just rebuilt smoked really lightly at start up, and then only for maybe 30 seconds....then ran like a charm.

Just a thought or two.....hope it helps.

 

[Kubota Newbie]

Was it doing this BEFORE you re-ringed/sleeved it too????

 

[wopster1]

iwas very careful assembling engine dont see how rings could of aligned. has no blow by. before i reringed & sleeved it was missing on 1. i checked compression it was 100psi. cyl1 had bad ring ridge valves were in poor condition had cyl head done and sleeves on 1&3 had 2 &4 honed and checked. ibought this engine not working wish i never saw it

 

[bruceatlam]

R U positive that you have the valves set correctly?

 

[firejunkie]

I have been working on Diesels for the better part of 23 years, on a rebuild your compression should be in the upper range of the specs, not the bottom range or below, could be a lot of things from as mentioned before, rings, valve seats, timing, a bad rebuild of the injectors, bad honing job, bad head work. Could be one or a combo of things. I have had machine work that was very poor, and have found many places over the years that know what they are doing, there is a difference between gas engines and diesels.

 

[fj40dave]

I've felt the same way......the last motor rebuild I did, I wanted to just call the owner and say "sorry Dude, but this isn't gonna come together for me"....but, I just kept at it, and presto - it's a great runnin rig now.

Keep at it.....after all.....it's just metal, oil, and fuel

 

[wopster1]

i have set the valves several times at spec below & above. rechecked compression this morning 325 cold 350 hot . ran it for a couple hours this morning seems to be idling much better. missing on 1 when reved i am begining to think there is a pump issue