Simon B Posted November 30, 2013 Share Posted November 30, 2013 When fitted the new frontera/Isuzu engine in my 110 I had to take the pump off to remove the immobiliser. I didn't have a set of pullers to remove the pulley so stupidly jacked it off using machine screws through the pulley against the back plate. It hates starting, as is if there is always air in the pump and the economy is down. Would pulling on the shaft in this way wreck it? If so can it be repaired? Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted November 30, 2013 Share Posted November 30, 2013 You really have not had a lot of luck with the Isuzu have you Simon! The only problems I've come across with the symptoms you describe it when the fuel stop pin in the return line from the pump is not working, this allows the fuel to run back to the tank overnight, Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 30, 2013 Author Share Posted November 30, 2013 It is running on a bit sometimes, this might be the same fault. Yes Dirty it's been a journey, but I am a bit stupid sometimes! I've still got the old seized engine but my wife wants her yard back so it has to go. Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 30, 2013 Author Share Posted November 30, 2013 I'm guessing that's the green topped solenoid on the pump? Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted December 1, 2013 Share Posted December 1, 2013 I'm guessing that's the green topped solenoid on the pump? That's the one, it should be powered up with the stop pin, so when you turn the engine off it locks the fuel in the pump. If you need somewhere to hide your dead 2.8 i'll take it off your hands. Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 5, 2015 Author Share Posted November 5, 2015 Just resurrecting this very old thread, continuing problems have led me to look at my pump and the Frontera set up. If anyone else is thinking of using an old Frontera motor bear in mind two things; The green solenoid is a solenoid operated bypass circuit that puts the timing 5 degrees advanced across all revs (bypasses the normal advance/retard function in the pump). Called a KSB Bosch term for a cold start device, 12v live energizes it and gives you the advance. Frontera's have timing marks at 12 degrees BTDC not at top dead centre. So I had basically set my timing up to be 12 degrees advanced plus another 5 = 17 degrees advanced...! Noisy! I have now coupled this cold start device up to my glow plugs so when I start the engine its advanced for a few seconds. As you might expect the engine runs very much smoother and starts instantly. Fuel economy looks a little worse and it seems hotter on the gauge. Will keep people posted on anymore news, hope this motor is good for a while. Quote Link to comment Share on other sites More sharing options...
RatCav Posted November 5, 2015 Share Posted November 5, 2015 The cold start device (in original application) reads the coolant temperature (either on the thermostat on the 2.8 4JB1 or the wax start on the 3.1 4JG2) It only advances the pump for a few seconds while it gets some heat into the engine. Then as you say it retards the pump. Officially it is call the QOS (Quick On Start) system What the OP is describing is what sounds like the pump actually out of time with the engine. If the pump is removed from the engine then there are two marks (one on the pump mount and another on the back plate the pump bolts to) You need to ensure the engine is at TDC (mark on crank pulley is vertical and inline with the pin poking through the timing cover. Also the cam and fuel pump pulley are at such a position that you can lock them with an M8 bolt through the hole at 2(ish) o'clock on the.Once all this is done you now need to get a depth gauge and insert it through the port in the middle of the injection line outlets at the back of the pump. Once you are at this stage you need to remove the M8 bolts and then go about adjusting the pump on its mount to make sure it is timed properly. That timing mark at 12 degrees (also at 10 and 11) are the marks used for timing the pump. You use the 12 degree mark for the geared version of the engine. The 11 degree mark for the intercooled version, and the 10 degree mark for the turbo only version. Another loss of power is not having an intact boost compensation line from the inlet to the top of the fuel pump. It is simply a length of 3mm id vacuum hose that goes from the port on the inlet system (after the turbo) to the port on the very top of the fuel pump. This line allows the boosted air from the turbo to push a diaphragm in the top of the fuel pump. This then open the pump more to allow more fuel through to compensate for the additional boosted air. Personally I would keep the QOS wired to its thermostat in the housing and time the pump up properly. My 2.8 1990 Isuzu Bighorn LWB Mk.I (2" suspension lift, 3" body lift, 4" flared arches, factory fitted high roof and running on 31" A/T's was getting an average of 38mpg after being timed up properly. P.S. I have workshop manuals for both engines. Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 6, 2015 Author Share Posted November 6, 2015 That's interesting, so l could make my adjustment even more efficient if I time it to the inter cooled 11 degree setting. Could I use the QOS thermal switch without a relay? I used a dial gauge to set it crack 0.5mm. Quote Link to comment Share on other sites More sharing options...
RatCav Posted November 6, 2015 Share Posted November 6, 2015 Technically it should of been set to the 11 degree mark in the first place as all Frontera's using the 2.8 were intercooled. When we did mine we set it up according to the book. We ignored the QOS and what it does. Set the pump up (had to be removed to be resealed) on the money. I.e. engine to TDC. Mount pump so the marks were aligned between pump mount and the plate it bolts to. Put depth gauge into the back of the distributor head. Now the gauge should be set to zero. When you put it in it should move to 1mm. Turn the engine to 30-40 degrees BTDC. The needle on the gauge should now be static. You can make sure by turning the crank backwards and forwards a bit and make sure the needle doesn't move. Now reset the gauge to 0mm. Turn the crank to the 11 degree mark. The gauge should now read 0.5mm. If not you have to loosen the pump mounting bolts, turn the pump on its mounts a bit then go at it again. Keep doing it until you get that 0.5mm. Now in my particular case I did this (using the 11 degree mark and drove it for a few days. It was quite knocky when on full chat. We obviously had the pump a bit too advanced so we just loosened it and retarded it a touch. Truck is now quieter, pulls like a train (quicker than my 3.1 Trooper LWB) and as said even with all the mods and brick like aerodynamics can get to 38 mpg with careful driving. Quote Link to comment Share on other sites More sharing options...
RatCav Posted November 6, 2015 Share Posted November 6, 2015 As for the QOS I am not sure how it is wired personally. I have always left it alone. It does its thing and works fine .. well it does on both my Isuzu Bighorns (Troopers). I will have a look when I get some time after I have pulled the gearbox off my P38. Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 6, 2015 Author Share Posted November 6, 2015 RatCav, That was the procedure I used, so my 12 degree setting is better but I'll set up 11 degrees when I get some time. The wiring is missing from my QOS system so I wired the green solenoid through to the glow plugs to give an advance when the plugs were on. There seems to be just enough time to start it well like this, I'll see when it gets colder. Next step would be to use the QOS thermal switch to operate a relay to the solenoid to make the advance temperature related as per original Isuzu/GM design. Shame I only just found this out, its been running badly advanced for a couple of years/20,000 miles. I'll repost when I have done the 11 degrees adjustment. I would love to make up a 3" bore straight through exhaust for it, might be a project for next year, did wonder about stainless and TIG weld it up I can borrow a set. Quote Link to comment Share on other sites More sharing options...
RatCav Posted November 6, 2015 Share Posted November 6, 2015 Hmm .. you don't really want the QOS running every time the glow plugs kick in. It only really operates when it is really cold. Even then it runs for longer than the glow plug after timer. I am assuming that it always sounds like a bag of spanners when it starts due to the extra advance every time you start .. even with a warm engine. Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 6, 2015 Author Share Posted November 6, 2015 It did previously, then the cable snapped on the green KSB solenoid alerting me to a change, hence the investigation, wiring it to the glow plugs leaves me the option if its warm to simply wait till the glow plug relay times out and clicks off before I start up, when the engine is warm this is quite quick so I'm presuming there is an ambient temp function in the relay . Its using the standard land rover relay timer which doesn't have a long after glow or reduced voltage after glow if cold. Quote Link to comment Share on other sites More sharing options...
RatCav Posted November 6, 2015 Share Posted November 6, 2015 One of the other thermostats in the thermostat housing provides the ambient temp for the glowplugs That should help Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 8, 2015 Author Share Posted November 8, 2015 Taken it back to 11 degrees, will see if the economy improves. I'll do the QWS switch connections when I get more time. Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 17, 2015 Author Share Posted November 17, 2015 Economy has indeed improved, still sounds a little soft so I may try 10 degrees BTDC unless people think this is a bad idea. Also just fitted a gas strut door stay kit... Why oh why did I not do this years ago. Work light next. Quote Link to comment Share on other sites More sharing options...
RatCav Posted November 18, 2015 Share Posted November 18, 2015 I would leave as is Quote Link to comment Share on other sites More sharing options...
Simon B Posted November 19, 2015 Author Share Posted November 19, 2015 Sound advice and its a bit cold to be outside with a dial gauge. Did an airport run yesterday, 160 miles. Going there (supermarket glug diesel) 30mpg coming back BP Ultimate Rocket juice 32 mpg. Might run this type of fuel more often. Quote Link to comment Share on other sites More sharing options...
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