Offroad-Express

hi i have a truck with a isuzu 4jb1 NON turbo engine, it smokes and misses on start up, the glow plugs are working (bench tested) and there is power getting to them when in engine, it also has 400PSI of comprestion even, (specs say it should be 441PSI) any ideas?? it started smoking stright after a oil chnge, it has had a number of differnt oils in it over the lst few years of this problem, TIME TO GET IT SORTED,

thnks nick,

Assuming its blue ish coloured smoke , clears when warmed up could be valve seals ? First choice would have been glow plugs but you have checked these, think they have full voltage as water temp increasesinitially then controller decreases voltage , on that model. Possibly oil control rings.

If black smoke its fuel? air related.

corosafari wrote:Assuming its blue ish coloured smoke , clears when warmed up could be valve seals ? First choice would have been glow plugs but you have checked these, think they have full voltage as water temp increasesinitially then controller decreases voltage , on that model. Possibly oil control rings.

If black smoke its fuel? air related.

hi its whitish blue, its had an aftermrket glow plug timer fitted and has 11.8 volts

Ok if valve seals leaking , some oil from up top will run into cylinder and burn off at start up , the effect of this will reduce as engine warms up.
Oil rings at bottom of piston return excess oil to sump from cylinder liner , if these are damaged or worn it will generally blow all the time.

Note this is my humble opinion and some fine tuning of my description may be followed up by more automotive mechanic type , you could park the Isuzu in the engines I have worked on and they dont have valve seals

valve stem seals it sounds to me cheap to buy labour not so sure

hey ll, had word with a diesel specilist tody, they seem to think poor injector spry and the white smoke is unburnt diesel, they will check injectors for free, if they need repait its expensive so please keep an eye out for some cheap non turbo injectors just in case, ill keep you all posted but please still offer your oppinions,
thanks

however if they do prove to need repairing, buyin a 2nd hand set could present exactly the same problem or could be worse than wat they are now. and could cost you more in the long run. do it once do it properly, short cuts lead to long cuts.

yes agreed , had black smoke in mind for poor injection but yes white smoke can be injectors , more blue for oil burn. Injectors will be less labour than valve seals and more likely I think , probably find when you test them that crack off pressure is low due to springs worn , always good to know your injection spot on as poor combustion otherwise , not good for engine . Always tricky diagnosing engine in cyberspace haha. Also took your comment about it being worse after oil change , the detergency factor in diesel oils can remove oil sludge deposits that may have been helping seal leaky seals to certain degree , thats why diesel engine turns black quickly as it holds carbon and the other products of combustion in suspension , otherwise it just forms a sludge build up.

nizmo wrote:hey ll, had word with a diesel specilist tody, they seem to think poor injector spry and the white smoke is unburnt diesel, they will check injectors for free, if they need repait its expensive so please keep an eye out for some cheap non turbo injectors just in case, ill keep you all posted but please still offer your oppinions,
thanks

mud_slinger wrote:however if they do prove to need repairing, buyin a 2nd hand set could present exactly the same problem or could be worse than wat they are now. and could cost you more in the long run. do it once do it properly, short cuts lead to long cuts.

yes very true, however quoted at least $1000 to rekit injectors, i seen a few sets kicking around for $100ish, i know its not ideal but i wont be using truck enough to justify that kind of money, not to mention im halfway through a hilux rebuild, thanks for all your guys help, it good to get a wide range of oppinions

wow 1k is them gold plated too

nizmo wrote:yes very true, however quoted at least $1000 to rekit injectors, i seen a few sets kicking around for $100ish, i know its not ideal but i wont be using truck enough to justify that kind of money, not to mention im halfway through a hilux rebuild, thanks for all your guys help, it good to get a wide range of oppinions

WTF? Thats not much cheaper than having 6 1HDT injectors reconditioned Have you tried elsewhere?

DaveM wrote:

nizmo wrote:yes very true, however quoted at least $1000 to rekit injectors, i seen a few sets kicking around for $100ish, i know its not ideal but i wont be using truck enough to justify that kind of money, not to mention im halfway through a hilux rebuild, thanks for all your guys help, it good to get a wide range of oppinions

WTF? Thats not much cheaper than having 6 1HDT injectors reconditioned Have you tried elsewhere?

two places so far, thats trade price too

it only cost me $100 to get my injectors reconditioned but that was mates rates, also got a second set for $35 /ea. I still have my old injectors. This is for a 4jg2 3.1 diesel engine not to sure how different it is from your model.

Cheers.

Drurban wrote:it only cost me $100 to get my injectors reconditioned but that was mates rates, also got a second set for $35 /ea. I still have my old injectors. This is for a 4jg2 3.1 diesel engine not to sure how different it is from your model.

Cheers.

awsome price, ill do some home work on injectors but im picking they will be differnt,

Been living with that on one of my Bighorns for 5 years and 120,000km. Mechanic said valve seals and not to worry. Never got any worse over time. Just a bit of blue/white smoke on first start of the day. After that good as gold.