Isuzu Trooper Owners Club UK™

[eithan h]

If it flashes when cranking that's a sign it's not seeing
The cam and crank sensor at the same time, I'd concentrate on checking the signal first

[Google]

[fbarron]

how do you check that signal. sorry wiring is not my strong point.

just a little update. tiped a spanner of the dome nut as i was pulling it up from brlow after dropping it into no mans land and the dome nut broke off. i pulled out the cylinder and the head where the diesel pipe gpes on was cracked. balls

[fbarron]

update. all back together and no go.!!!
i opened the fuel pipe  coming from the hpop and only a dribble of diesel is coming out. is that normal or should there be pressure.

[fbarron]

now im confused. put her all back together and gave it a pull and she started after a bit. ran fine but when you take your foot off the throttle she dies. started off the starter put ran lumpy for a minute until it tokk off like *beep* of a shovel. any ideas anyone. im going nuts,

[Browndoff]

Sorry to 'blame the patient for his illness' - but you're leaving-out vital bits of information needed to help you!

[1]    "dome nut broke off"  seems to say you've broken some parts - yet you make no mention of repair or replacement of them..........?

[2]    "runs lumpy - then 'took off'"     sounds like dirt blocking a fuel-filter/fuel-pipe and then coming loose...........? Yet you made no comment when I suggested, earlier, that you replace the fuel-filter and clean out the filter-body. You've got to ensure a good flow of fuel from the pump when it's cranked-over.

[3]    Eithan mentioned that the 'Check Engine' flashing during cranking-over implies a faulty position-sensor on Camshaft or Crankshaft - yet you seemed to say just that testing THAT was too difficult.....?

You've got to test out these ideas and report the results, so that others can help you by knowing whether, or not, the early 'diagnoses' were right. If you don't even tell us if you've TRIED them, folks will just think it's pointless to offer any help!

[fbarron]

dome nut and the sleeve replaced.
filter and lines are ok. it wont start from a jockey tank directly onto the hpop.
the check engine light is not flashing anymore cos when i reconected it after checking out things it was a little loose. probably got distubred in the rooting around.
so
im snookered.  going to pull it again now and give it a long run. will update later assuming it gets me home

[Browndoff]

OK - "the check engine light is not flashing anymore" - I hope you mean that it comes 'ON' with the ignition switch and goes 'OFF' when the ECM does its little check routine??

That light IS IMPORTANT! You need it to work to be able to do any 'On-Board-Diagnostics' - so you can't ignore it if it's not working now. [If it were just a bulb - and you had no spare - you could put one of the bulbs from the indicator-telltales in its place. DON'T just leave it blank!!]

"dome nut and the sleeve replaced" - good! Are you now getting a decent squirt of fuel out from that Domed-Nut - if it's loose when you crank it over? If it were NOT able to 'deliver' the fuel, then you'd still have another problem in that area.........! The 'Jockey-Tank' only makes the fuel 'available' - the fuel-pump and the fuel-valve must send it into the head!

Good luck with the TOW!

[fbarron]

towed it and it started after a bit.  ran fine and i gave it a run. 20 miles and when i pulled in and turned it off it started fine.
waited 10 mins and started it again and it wouldnt rev for a while./
the squirt coming out od the diesel pipe is miserable,
i think the lift pump element of the hpop is knackered

[Browndoff]

" it wouldnt rev for a while! = throttle-response is awful!  Seems likely to be a FUEL problem!

"the squirt coming out of the diesel pipe is miserable" OK - it's poor flow-rate - but is it CLEAN fuel? Without AIR or Water?

"filter and lines are OK" How do you know? Have you replaced the fuel-filter [it doesn't have to LOOK dirty to be semi-blocked by fine particles]?

"i think the lift pump element of the hpop is knackered"    The filter is a MORE LIKELY suspect , when things go wrong - and they're CHEAP!

Other Data Readers [beside the hugely expensive Tech-2] will give useful information on the running engine - which you can then compare to the 'sticky' on 'ideal' readings for a Tech-2 [Starting Issues, I think]. They ALL read them from the OBDII Connector, in the same format and even in the same order. If it shows that YOUR machine is NOT RESPONDING to the throttle, in the matter of changing Rail-Pressure, % opening of the ROPCV and delivered fuel quantity [mm^3/stroke] then it WILL indicate where your problem lies. NOT ALL of such problem will show up as DTCs - but comparison of running data with the 'ideal' will tell you a lot!

[fbarron]

filter and all lines are clean as a whistle. it does seem to be a fuel issue. but if i put a can of diesel direct onto the pump and crank it the flow is still miserable form the dome nut

[Browndoff]

The Isuzu Manual specifically recommends that the HPOP/Fuel-Pump NOT be stripped - as it's very complex. Thus, it provides no information on the internal structure, nor offers replacement parts for any internal component. Unless you're especially gifted at 'reverse-engineering' - you might well be advised to leave it alone!

That leaves you with only the option of replacing the HPOP completely - an expensive part - or finding someone with a Data Reader capable of reading the running-engine data from the Trooper. That would, at least, give you confidence that your own analysis of the situation was correct - and that you had no choice but to replace the unit. It's a costly exercise, too, but it might show up another possible explanation of the symptoms....? If so, that would save you the wasted cost of a new HPOP which would NOT solve the problem!