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Discussion Starter #1
ajhengland u seem to know these any help from any one please put a new head with injectors turbo and pump on still the same has a sort of hesitation missing until goes over 3k revs then goes like a train but doesn't go over 42k revs think it limited any way put cam and crank sensors on air flow not genuine but new did go good for few miles when put head on but back to normal and I'm gonna scream any help please
 

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"Red One.."
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I've seen peeps with such problems with non genuine airflow meters, so that's the first area i'd be looking at. EGR valves can stick, you can unbolt them and turn them 180deg round the other way which essentially blocks them off in order to test and confirm that one.

There is also a small 6mm rubber pipe that comes off the back of the inlet manifold and runs up to the boost pressure sensor (bolted to the metal case of the control unit) - where the rubber pipe joins the orifice on the manifold, run a small drill bit through the orifice by hand as carbon can block this solid and cause incorrect boost readings.

With access to a decent scantool you can check and confirm any DTC's or glitches in the live data too.
 
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I've seen peeps with such problems with non genuine airflow meters, so that's the first area i'd be looking at. EGR valves can stick, you can unbolt them and turn them 180deg round the other way which essentially blocks them off in order to test and confirm that one.

There is also a small 6mm rubber pipe that comes off the back of the inlet manifold and runs up to the boost pressure sensor (bolted to the metal case of the control unit) - where the rubber pipe joins the orifice on the manifold, run a small drill bit through the orifice by hand as carbon can block this solid and cause incorrect boost readings.

With access to a decent scantool you can check and confirm any DTC's or glitches in the live data too.
I've turned the egr and cleaned the port for pipe still the same
 

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"Red One.."
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I'd certainly look at even trying a donor, genuine airflow if possible then - I've seen several other's on here that have had issues with non genuine meters. What make is it?
 
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Help still needed people please going to strip harness back any particular place to check apart from injector wires
 

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"Red One.."
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Take it no warning lights on the dash.? Have you had it plugged in and checked for codes and more importantly data.? That'd be ideal really, to watch boost data and fuel pressure during acceleration to see if either look low, grey ish smoke would suggest overfuelling or underboosting.
 

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Discussion Starter #14
I have litteraly changed everything on this head and gasket with injectors from a running car just had different bottom end new crank and cam sensors turned egr and tried another new aftermarket air flo and map sensors did seem to go ok when first put head and everything on then after a couple mile back to how it was so thinking wiring
 

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Well think you will have to get serious now, you seem to have changed nearly everything, have you got OpCom, if not might be worth getting it, with that you can monitor just about everything one the vehicle....you need to check it for fault codes if you haven't already, if there are no fault codes suspect something mechanical like a blocked exhaust or dpf filter, blocked cat, if it has one, the fact it does run fairly well to me would eleiminate the the valve timing and compression's etc...they do suffer from air getting into the induction side of the pump, from tank to pump, and around fuel filter...with OpCom you could check she fuel pressure....the signal on te MAF sensor, have a good look round for basic things, like air leaks blocked exhaust, bad fuel that sort of thing...good luck...well few thoughts anyway...does it use water or oil...from Fred in Essex uk.
 

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Discussion Starter #16
Not using oil or water removed cat had tank off cleaned it were does the fuel system tend to leak got snap on souls pro what is the pressure supposed to be pls tia
 

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Not using oil or water removed cat had tank off cleaned it were does the fuel system tend to leak got snap on souls pro what is the pressure supposed to be pls tia
Well can you check the pump pressure with that, maybe you can, the pressure on the high pressure pump is enormous on common rail diesels....can tell you exactly but here is a message i made some time ago.....Fred.



Common Rail Diesel Systems

The common rail Bosch diesel fuel system, some have an electric pump in the fuel tank, and filter in or out of tank, the primary fuel system is pressurised to about 2.5 bar (45 lbs psi) plus or minus a bit, the secondary system comprises of a high pressure pump that runs off the cam belt, and pressurises the system to approx 1350 to 2000 bar (about 15,000 psi) which is fed to the fuel rail, the rail has the four injectors on, and a temp and pressure switch, the whole system is controlled by the vehicles on board computer here by known as the ECU, the injectors are fed with a 12 volt supply and are switched to earth by the ECU, which gets the information from a crank sensor, when you turn the ignition on it primes up the system for about 2 seconds, if the primary pressure is low the engine will be very hard to start from cold, as on most modern systems the glow plugs do not work until ambient air temperature is below 0 degrees C, the whole management system works via relays and fuses, it also has a warning light on the dash, make sure this light works correctly, if it stays on there is most likely a fault code stored, and you need to have a code reader to be put on it to check for stored codes and clear them, if the light is on, and under some other circumstances, the management system may revert to "Limphome Mode" that's where some thing on the system is wrong or not working and the ECU gives the system an average set of parameters to get you home, to avoid total breakdown.

If the vehicle fails to start...

Or runs poor, first make sure you don't have wrong or contaminated fuel, then undo pipes on filter and crank to
see if fuel pump is working, (if it has one), if not suspect, pump, relay, fuses or Inertia switch, if that bit is ok undo union on input to fuel rail, crank over and check it squirts out, be careful very high pressure, just look, the system has a fuel return on it from high pressure pump and fuel rail, which lets any unwanted fuel to return to the tank, if you have no supply when cranking suspect high pressure pump fault, if ok check pressure at either end of the injection pipes, should run out liberally , if not could be pressure switch allowing fuel to go back to tank, if you have fuel coming out of pipes when cranking and still wont start, check the power to plugs on injectors, should switch on and off 12 volts when cranking, if nothing there check fuses and relays also crank sensor and ECU, pin 1 on Bosch ECU should be live with ignition on. also if it won't start may want to
think about Imobilizer fault and /or ignition Key fault. although if the key is faulty it normally won't crank over.
may want to check the system for trip switches that might have come out, might be wise to run through all fuses with circuit tested with igniton on. it may also fail to start if the temperature sensor is faulty. Don't forget These are of course compression ignition engines. You need to establish a few things, like is there an electric pump in the tank, if so does it work, if not the high pressure pump is made in two sections, the bit that sucks up the fuel from the tank, make sure there are no restrictions and no air leaks on that bit, and the second bit is the high pressure pump that supplies the injectors with fuel, a lot of these new electrical diagnostic machines can check fuel pressure electronically, also check O rings and stuff on the high pressure pump, make sure there are no leaks and not drawing any air in anywhere. The main things to check if it wont start are, has it got compression, has it got a fuel supply and are the injectors triggering, a drop of easy start can prove a point, but that will fire up engine even if it has low compression so consider that, make sure the valve timing is right and the air and fuel filters are clear.

Also if the secondary pressure is low it will cut off the current to the ECU pin 1 and the Injectors, so remove
all the leak off hoses from the injectors and block the final hose as to stop fuel pouring out of it, crank the engine for several seconds, the leak off ports should just drip a bit, if it runs out any of them that injector is faulty, if it runs out of all of them renew all injectors, one is enough to make the pressure in rail fall as to cut off all injectors if it tends to fire on one cylinder and won't pick up the bores might be full of diesel, try removing fuel pump relay or fuse, take top off filter, make sure no new fuel comes in, and crank it over to try to get rid of any excess fuel, then see if it will run on easystart, if it won't run up on easystart it prob won't run on diesel, of course the injectors themselves might be squirting fuel in instead of spraying it in, in which case you will need to get the injectors tested. Beware some later injectors work on high voltage like 80 to 120 volt and shouldn't be disconnected when running. Some are solenoid and others piezo electric type. Just a way to check the fuel pressure if you dont have any special equipment, find the fuel rail pressure switch, there should be 2 wires on it, check one for 5 volts with ignition on, then check the other side of the switch with it cranking or running, make sure the 5 volt wire is on the switch, you can do it with both wires on switch, and check for 1.3 volts cranking and up to 4.5 volts when running, if you get about 0.5 volts you have no fuel pressure. You should get 0.5 volts on that signal wire key on engine off.

Another way to check injectors is to take all the leak off hoses off as above, block final, get 4 small glasses, and 4 pieces of plastic pipe, put the pipe from leak off ports to glasses, may have to block off the other side of the leak off on injector, crank or run engine to see how much goes in the glass, the less the better, should just drip, they should all be even, if it runs in, that injector is faulty, the longer you crank the better.


Also it might be worth removing the pressure valve on the end of the high pressure pump, sometimes on fuel rail, the one i have seen is held on with 2 10mm bolts, remove these and pull the valve out, inspect the 2 O rings for splits and with a magnifying glass look at the tip, there is a very small opening which could get blocked. if looks ok refit it and refit plug. Could try tow starting it. problem was with mine blocked injectors, prob muck got through filter. Make sure the exhaust isn't blocked, or inlet. Just one comment, if the MIL, (Malfunction indicator Light) doesen't work and it's not the bulb or wiring etc, suspect faulty ECU or it's wiring,
specifically the 5 volt reference circuit, also will prob find the code reader wont communicate with onboard computer either.


If you have problems getting car through smoke test, best approach is put a ton of diesel injector cleaner in the fuel tank, clean or change air filter, wouldn't hurt if you changed engine oil and oil fiter and fuel filter, but unlikely to make much difference, give the vehicle a good thrash up the road for about 3 to 5 miles before you take it in for test, don't let it get cold or idle too long, if it still fails will prob have to take it to a diesel specialist and maybe think about injectors or injector pumps etc...

Note: Above where i put 4 injectors on rail, it does of course
depend how many cylinders the vehicle has, might be 6.

Fred G4VVQ. 2016.
 

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"Red One.."
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Common rail pressure ranges from around 245bar tickover (will most likely read 24500kpa in the actual data list) up to around 1500bar (150000kpa) when on absolute full throttle/full load when driving.

Check the boost pressure with the engine off/ignition on, it should read the same as the barometric pressure of around 97-100kpa at around sea level, and this figure should read the same when the van is ticking over. From memory max boost will be under 200kpa when driving, you can monitor to make sure there is a nice smooth progression in the boost curve.

None of the common rail injectors operate off 12v, they're likely 80v to fire them, and will only pulse when the van is starting or running, so no voltage present at them with the ignition on.

It's a bit more difficult on these earlier vans - the later stuff shows 'desired' pressures in the data list for all driving data, so gives you more to compare against.
 
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