How to fix an injector pump of 4jx1 engine - 2002 Isuzu Trooper

Hi, how about re-calibrating your engine? Get a certified engine mechanic and have your car calibrated....

The injectors sit in engine oil on that engine, i would say 1 of the o rings that keep the oil out is worn and allowing oil to return to the fuel tank. I would get a seal kit and do them all.

Where are you finding this? Diesel and water would normally only mix if water was getting into the fuel tank. Are you sure it is diesel? If you are finding it in the coolant reservoir it is more likely to be engine oil. This usually suggests a blown head gasket.

It`s a diesel Engine no spark plugs.
More than likely it is your injector seals .They have to be replaced

This is typical of o-ring "seals" in the injector systemof the 4JX1 engine losing seal quality which will mix oil and coolant together and return both into the fuel tank and radiator. Smell the radiator. Most likley will smell of diesel fuel and perhaps show oil if you dip a timber ice cream stick into the radiator. Often occurs after overheating (towing or low on coolant). Buy an electric "ratchet" pump on eBay if you are going to fix the injectors [1 0-ring] yourself (and the sleeves [2 o-rings] per cylinder. You need a sleeve removal tool also. Instructions are available on Australian 4WD forum. The pump is to pump out of the fuel tank before you start the job. Take the input fuel line and hook into the pump. A plastic tube of the right size onto the outlet side and energise the pump. Drain into a 2 litre container(s) until diesel shows up instead of water. Drain the coolant before starting the engine repairs as some coolant pipes are made with rubber component pipes and could deteriorate if left too long. You need a copy of the manual (free online - do a search). You need to tighten the oil rail and injectors to the routine given to ensure good sealing. New copper washers for the injector ends are essential for good sealing. Ive had good results from using old rings for sizing and replacing with Vitane o-rings from hydraulic supply dealers. Label clearly when purchasing. Do not use standard rubber as they are not temperature rated. O-ring on internal injector plunger is "ceramic" and is not feasible for normal repairers and is usually not required. .RichW

you need to set the timing to top dead centre and the flywheel has a little knotch in it set that at 6 oclock will start then

the engine oil pumps are in the rear of the engine(trans out) and behind flexplate /flywheel, were any of these 2 engine oil pumps touched if so the flywheel /flexplate has to be timed to crankshaft position, so you might have it in the wrong position, if your talking about the diesel lift pump (injector pump) that also supplies high pressure engine oil to injectors, after replacing this there is a learn procedure for the rail pressure control valve that is on pump. this can only be done by dealer or some one with Tech2 scanner tool.

Buy a can of throttle body cleaner take off the air filter box, follow the tube and then spray the throttle body and wipe it out first before condemning the injectors

You have no injection pump ,each injector does that job .
You have a faulty rail oil pressure sensor I think ,read my tips to test this sensor .

my isuzu bighorn will not start after changing valve seals and head gasket and after setting timing it still will not start. do you have a solution.