Hi, i've changed the diesel pump on my 2005 Isuzu Kb 300 4jh1 now it won't start and shows ecu error p1651. What can it be?

SOURCE: Isuzu 1997 KB 260 Workshop Manual

try haynes.com or your local parts store for a Haynes manual.  For around $20 they are frequently as good or better for home mechanic than factory manuals for $100.

SOURCE: isuzu 2001 diesel engine won't start

cant start deisel 3.0 lilter sounds like there is no fuel getting to the engine

Simon

• 235 Answers
• Posted on Aug 25, 2009

SOURCE: Isuzu bighorn diesel 4jg2 engine timing diagram

http://www.jeepolog.com/UserFiles/downloads/trooper_manual.pdf

This site has it .

SOURCE: I have a problem starting

Seems you may have a similar problem on your machine to the one we've had....The 4JX1 has taught us a lot we didn't know before, but specificly for this particular engine. First I'll advise you check the obvious things...Make sure that your battery is charged fully. I'll explain why later. Next make sure that there's no air in the fuel system....On the filter housing you'll see a ten millimeter bolt, which should be loosened and once loose push the plunger atop the housing to remove any air....If bubbles come out you'll know that that was the problem or part of it. With this particular engine the ORPS (sensor) gives the type of problems you're talking about. The sensor in question is fitted inside the tappit cover into the oil rail (which is the cylindrical pipe fitted over the valve assembly....It has two sensors, one being the ORPS and the other being an oil temprature sensor. To get to these it'll mean removing the tappit cover which means first removing the inter cooler....then the oil feed pipe which fits into the side of the cover, Remove all the screws (five each side and three at each end)....The ORPS is the smaller of the sensors....It is a sensor which operates with a cystal....The oil preesure pressing against it will cause a very small voltage which is actually a pulsed signal....That signal is sent to the management computer and controls the solid state switch which allows the circuit for the injectors to beecome active....Remeber the battery? If the battery is not able to turn the engine at what you'll hear as a normal speed the oil pressure will not be enough to send the signal which opens the injectors....The ORPS (Oil Rail Pressure Sensor) cost's about two hundred and twenty US$ and if you do the job yourself your probably save a similar amount on labour charges....The engine oil is also critical....Only use the recommended oil....If that has not been used....Buy double the amount of the correct oil and two of each filter....Drain what's there and then refill with the recommended oil (once vehicle is up and running) run the engine for thirty minutes or so (pref on the road) and then re drain and again fit the other set of filters and refil....We don't like the chemical engine flush addatives, too dangerous, esspecially in a diesel engine.... Hope this is help Ron Let me know how you get on. you can send your reply to this same web site...I'm one of the experts.... Cheers for now.... Best regards Johngee10

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