Any diesel mechanics on here

mudguts2, Mar 7, 3:15am
we have a isuzu motorfor our bus.
it idles good no smoke but once power is put on it has cloud of whitish smoke and misses.
think it is fuel any ideas.

isuzu BD1 is the motor.

intrade, Mar 7, 3:41am
yes hi first you want to use a diesel additive like chemtech or winns -edt to prevent fuelpump seal shrinking and or pump wear from the low sulfur diesel.
Now to your discription
It does sound like you have one or more faulty injectors. Does it do this all the time cold andwarm-hot!

mudguts2, Mar 7, 3:45am
yes start it up and good as gold cold until you put power on.
then misses and puffs.

runs perfect otherwise.

intrade, Mar 7, 3:47am
answer all questions please .
1# does it start fine cold .!
2# is the aircleaner clean !
3# is the fuelfilter new!
4# has it got the normal power !
5# was the valve-clearnace done !
6# did you ever check for fuel leakes on injector pump !
7# do you use additive and or injector cleaner!
8# does it use engine oil and if much!

mudguts2, Mar 7, 3:54am
#1 excellent start
2/3/4/7 all good.
8 doesnt use oil.

so just leaves 5 and 6
no to valve clearance
and havent checked for leaks

but got somewhere to start looking.

intrade, Mar 7, 4:14am
ok report back. basically no 1 reason for coughing on diesel is a faulty injector.
white gray smoke is un-burned fuel. there are other resons but thats the top cause.

big.b-lil.c, Mar 7, 4:49am
white smoke is unburnt fuel. can be a sign of a blown turbo or incorrect injector pump timeing

mudguts2, Mar 7, 5:25am
is a non turbo.
but will update once we have checked.
thanks for replies

tokyo_rose, Mar 7, 6:30am
white smoke can also be caused from brake fluid getting into the vacum/ intake system by using the brakes & the hydraulic fluid leaking out of the master cylinder into the brakes vacum booster.
This wont be a probelm if you have full air brakes & will only apply if you have vacum& hydraulic brakes as the old beddys had etc

digger80, Mar 7, 7:09am
we just done a 6 cyliner 6bd1T,had similar problem,it had broken injector drive plates,from compressor,puts timing out,only 3mm or so,but they don't take being out,at all,good luck

mudguts2, Mar 7, 7:18am
sounds like this one.
pretty sure we are onto the prob here.
will get it into diesel services for a check.
thanks.

this is the 6BD1 also.
just swapping from the old beddy motor to something with a bit more power.

digger80, Mar 7, 7:26am
I've done a few conversions the same,they go well,hope this is your problem,as there's not much more to go wrong with these motors,the one we did drove out,just last Friday,complete with Isuzu gearbox,thanks

digger80, Mar 7, 7:29am
just looked where you are from,take it to Warren,down the bottom of old Taupo road,he's a wizzard on those,Diesel Services

supernova2, Mar 7, 7:32am
I had something similar, turned out to be a bit of dirt in the fuel filter head, ran fine until filter ran dry then pump had to fight to keep up fuel.Everyone thought injectors, timing, worn rings you name it.Process of trial and error and discovered hand priming to fill filters took like 20 mins.Bit of compressed air up the lines and fixed.Maybe you have similar probs

digger80, Mar 7, 7:40am
hi super,
there is a gauze [or supposed to be],in the intake banjo bolt to the lift pump [primer] that gets blocked easily and regularly,if there's a dirty fuel supply tank,where you fill from

supernova2, Mar 7, 8:37am
Yep, but my problem was at the filter head where the line from the tank connected so in effect the pump was sucking against a blocked pipe.The blockage was actually inside the filter head.Probably 99% blocked so once it got vacuum if you left it for a couple lof hours would manage to refill thge filter and all was fine for about 500mts.Only pump on mine is the injector pump, it has a hand pump on top of the filter housing to prime the system (mazda b2200)

mudguts2, Mar 7, 10:19pm
thanks for that.
friend going in to see diesel services for me as work over in kawerau.

good to hear we on right track with isuzu motor.
beddy just a bit slow.getting tired to.

bash, Mar 8, 4:53am
take the feul pipe of the lift pump directly from tank you should find a little filter in the nut clean that out

mudguts2, Mar 10, 3:03am
prob was the coupling between the compressor and injector pump was flogged out.
which puts the timing out as soon as power goes on.
thanks for all input.

intrade, Jul 5, 3:40pm
good to hear you got it sorted .