Isuzu Trooper Owners Club UK™

[Browndoff]

I'm trying to help a young man with a 3.0 Trooper belonging to the FS Reserve -  which doesn't cut-out - but won't restart if left for 20 minutes.

Without access to a Tech-2, I tried to analyse the Voltages at the ECM-Connectors - see 5 pics at .

Then I compared these voltages to those shown at the ECM by my own Trooper - most were very similar - with the possible exception of the ROPCV - where mine showed 8.3V warm stopped, 10.5V at tickover and 11.5V at 2 500RPM.

I tried cutting the 'White-Wire' - it still would not start until cooled-down. I checked the fuel-flow [at the 'Domed-Nut'] at cranking - it was as good as my [working] truck. No DTC is displayed and the truck will start reliably FIRST-TIME when COLD.

I'd appreciate some help - as this truck is needed for rescue-work etc.

[Google]

[eithan h]

swap the ropcv for yours i've had that exact same scenario before and it was the ropcv but if you can swap yours it will prove it one way or another

[Browndoff]

I meant to supply rather more information:-





My thinking was that if we could create a 'general understanding' of what voltage-readings SHOULD BE at the ECM, then more people could diagnose their own problems with a simple multimeter - rather than needing a Tech-2 always.

Anyway, in this case, Eithan is probably right about the ROPCV - it does seem 'dodgy' - but they're such a pain to access that I was hoping to avoid having to take out - not one - but TWO!

[Gribble]

I think the ECU is best left alone ,it puts out 110v on the injector side and is sensitive to voltage changes ,also the ropcv works on milliamps and you need a good meter to read them accurately.

True its needs to be back probed for the CKS signal but the most common faults for a 3.0 not starting are well covered on here except there is no sticky for that

Yet -  
_________________
2 New Troopers !

[eithan h]

know what you need to be doing then mr G over the weekend!!

[Gribble]

Yes , Fitting CE marked hydraulics to a Dosco chipper,fixing  2 troopers ,fixing a clio (do not ask ) .

One is a non starting 3.0 so a pic post will be coming .

I will send it (the sticky list ) to Sir for approval as there are some ' grey' areas lol
_________________
2 New Troopers !

[Browndoff]

Further Info:-

Got a Data-Reader onto the Fire-Service Trooper today. Got it going easily [will ALWAYS start easily from cold] and ran it hard until reached Operating Temperatures and then ran a test with the gizmo plugged into the OBDII. It gave the same info in the same order and all the same details as displayed in the STICKY on Tech-2 Data. When HOT - it would not start at all.

It showed that the pressure reported by the ORPS [only 0.2 MPa] was way below required to fire the Injectors and the  ROPCV initially showed 25% open then went up to 90% - without any noticeable increase in ORPS reading [nor did it fire!]. It seems that the ECM is commanding the ROPCV to allow in more oil to raise the pressure in the Rail - but nothing happens - so the valve must be stuck. The ORPS seems OK 'cos the readings DO vary with engine-speed AND cutting the 'white wire' DID NOT allow a HOT restart.

It seems very unlikely [to me, anyway] that the HPOP is faulty, as it ran very well [up a steep hill etc.], just an hour earlier - so it has to be the Rail-Oil-Pressure-Control-Valve..............doesn't it? On this evidence, we stripped out the ROPCV and it LOOKED OK....?

The piston moved only 3,3mm and DID NOT clear the upper holes in the valve body, though this movement DID seem smooth enough [clearly the unit was entirely COLD at this stage and the fault occurs when the engine is HOT].

What's the verdict of the Expert Jury? Replace the ROPCV?

[eithan h]

Yep

[Browndoff]

Final Report on the Fire-Service Trooper:-            

We put in the ROPCV from a properly-running-engine [mine, unfortunately!] and it started first time [after clearing all the air out of the system!]. Just to be sure - after all, this beastie had ALWAYS started COLD - we tested it with the DATA READER. It showed a prompt change of ROPCV percentage when the foot-throttle was pressed and an immediate change in the actual ROPS pressure-readings - indicating that the Pump, the ROPS Sensor and the ROP Control Valve were all functioning as required!!

The engine, incidentally, was running very badly - so we WOULD NOT have known that all was well without the re-assurance of the Data Reader - but the stuttering was down to really lousy fuel - as we had noted earlier when we had to remove the fuel inlet-pipe. On checking, we found that the vehicle had been filled-up at a 'proper' garage - but, I suppose, even tanker-drivers occasionally put petrol in the wrong tanks!

Anyway, now she's back in service - thanks to the Forum's resident geniuses for help in diagnosing a faulty ROPCV!!!!