P38 2.5DT won't fire.

[neonovice]

ANOTHER UPDATE!!

Windows are now sorted (they magically sorted themselves) I now have another issue.

The engine fires no problem but if you try to rev the engine it bumps off some kind of limiter at 2000rpm. There are no errors showing on the dashboard.

Any ideas?

[STOVEBOLTSLIM]

The engine fires no problem but if you try to rev the engine it bumps off some kind of limiter at 2000rpm. There are no errors showing on the dashboard.

There is some sort of "limp mode" in the electronics? Read somewhere that there are 2 levels of limp mode (2000 & 3500 rpm) from memory.

Reading this old post as my 2000 X reg 2.5 DSE cranks but won't start. Have changed dead, in tank fuel pump, after intermittent poor starting became terminal, no sign of firing now, have purged air at injectors and am working through other ideas, but as I look more at this (M 51) engine there doesn't seem much electronic control, just peripheral stuff. Injection pump is mechanical, shut off solenoid looks like my old 200 TDI type, injectors are mechanical.

What does the BECM/ECM synchronysation affect that would stop the engine starting?

[pete3000]

help In order of expense........ the fuel pump as you say is electric and once you key to pos2 you can bleed the air at the block with the banjo bolt on the end of the clear tubing from the fuel filter. if the engine has been progressively harder to start from COLD then your leak-off tubing could be perished, the same tubing can be used to replace the vac pipe onto the inlet manifold.

To check this disconnect the mass air flow/corrugated end jubilee clip after the air filter, loosen the hose clip on the left of the engine and swing the ducting up and out of the way. Remove the 5mm Allen bolts and remove the plastic tray, then check the ends of the rubber tubing back to source.

Another £30 ish and you could check/change your 6 glowplugs if they have never been done. You'd tend to have a clue these had gone as you would have a lumpy start and possibly white/ unburnt diesel previous to non-start.

The fip does have electrics and a sync code paired with the BECM and this can become randomly unsyncronised, the cheapest way of sorting this is a syncmate from black box solutions. You'd be unlucky if this has happened but no real way to tell unless it suddenly wont start at all one day. and youv'e been over the above £100. video on youtube. You'd have no unburnt diesel as no fuel goes to injectors

On injectors the 3rd or 4th (can't remember) has a wire which is an anti-knock signal which alters the map slightly to prevent oscilation, the full description is in rave.

If it wont restart or start from HOT then it could be a worn FIP, the cheapest option to extend the life of the pump and your sanity is buy and fit a hot start kit from ebay. £25 ish.

HTH for now feel free to give me a shout if i can help.

Pete

[STOVEBOLTSLIM]

Thanks Pete, have red herrings to deal with as well.

Starter motor or battery seem to have lost speed and power, have 10 volts at starter and battery when cranking, understand this is the cut-off limit for ECM working correctly so bit doubtful. Swopped and charged batteries while maintaining 12 volts at connection to avoid any reprogramming/synching issues, noticed glazing inside battery terminal clamps, guessed I had baked grease on terminals while using starter for extended periods, cleaned connections and refitted recharged battery. Duh! no good.

Tried 3 good batteries in paralell to give longer bursts of cranking (starter motor was recon, fitted 9 months ago) no improvement.

Used 2 batteries in series wired direct to starter solenoid (not recommended, but what we used to do on Ford Escorts in my old rallying days) to give 24volt starting, with the standard vehicle battery just powering the electronics. Got engine spinning well and manually vented injector pipes but still u/s.

Got more desperate, only had small amount of white smoke from exhaust so suspecting fuelling weak or airlocked tried spraying WD40 into inlet manifold after disconnecting MAF pipe and while choking inlet with my hand to check compression/suction engine fired and ran smoothly.

Thought I had cleared airlock and went to bed.

Next day, put wiring back to standard, engine seemed to turn over faster but no start and then soon after, no starter motor. Removed and dismantled, no brushes left and comm. had been turned down really thin during recon. process, was not impressed by quality and then noticed small flywheel in pre-engaged pinion gear was damaged around it's perimeter and had been catching on something. Looking in bell-housing aperture, the starter had been catching on the crank position sensor dowels.

Removed and cleaned crank position sensor as it had metal flakes magnetised to it from starter motor.

Started to track down new starter and had conflicting info about correct item, the faulty was a Magnetti Marelli with threaded fixing holes but I was not convinced that was correct. Finally settled on a used Bosch/Land Rover unit from Emmotts of Colne, arrived next day and looked in super condition, it did not have threaded fixing holes but the bolts holding the Magnetti Marelli were easily long enough to take nuts and lock-nuts.

Engine spins great on 12volts only but only starts after lengthy cranking so still not there. Restarts immediately if only left a minute or 10 minutes, but after a couple of hours or overnight needs cranking. Will be doing injector leak off pipes next although they don't look bad, but I can't ignore the overwhelming opinion, hoping to find my vacuum tester gauge and investigate as I remove them.

[STOVEBOLTSLIM]

What does the BECM/ECM synchronysation affect that would stop the engine starting?

Answer: The needle lift sensor on no.4 injector, together with crank position sensor, calculates engine speed and regulates fuel flow from pump to injectors via quantity servo control unit and servo unit potentiometer, as pete3000 says, this also controls jolt damping (thanks Pete)

If the above components are faulty there is no limp mode, ECM gives zero fuel flow = shutdown (deduced from RAVE cd manual)

[pete3000]

If you have it starting on diesel now after lengthy cranking, i'd go with either air bubbles in the clear tubing from the fuel filter meaning air is getting in overnight? via leak off or fuel lines or needs glowplugs if it restarts ok when hot.

Not a BECM/sync issue if it will fire and run albeit roughly.

Glowplugs are likely to have one or two down depending on age and service history, you can check current draw but they may be carbonised/sooted up anyway?

Cant beat a hotstart kit to give you a bit more fuel with glowplugs on hotstart or borderline enough fuel making it to the injectors though.

http://www.ebay.co.uk/itm/Hot-Start-Starting-Fix-BMW-Vauxhall-Opel-Omega-M51-Diesel-Engine-/390352398314?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5ae2d0e7ea

Sounds like you're almost there.

Pete

[STOVEBOLTSLIM]

Progress. Tested leak off pipes with my old vacuum-advance test kit, they would hold a vacuum so not convinced air was entering, from the way it's laid out thought that any air would be pushed straight down return line to tank and not affect pump operation.

Decided to take off inlet manifold and have a better look at the electrical plugs and glow-plugs that I could see underneath. Before I knew it, the manifold was off (plastic type so could re-use seals). Plugs were oily on outside, but terminals were clean and bright when I unplugged them so turned attention to glow-plugs.

Four of the 8mm. terminal nuts unscrewed ok but two of them started to twist the terminals and I was glad I had not attempted removing the glow-plugs with manifold in place. After a closer inspection I realised the cores of the two glow-plugs had completely broken so I just slid them out, held them with pliers and got the nuts off without damaging the loom. Used a 12mm x 3/8" drive socket, just managed to engage it on the flats and removed all six (Beru 0 100 221 163) glow-plugs. Disappointingly they all looked quite new and after cleaning off a bit of light carbon and some harder white residue they appeared sound, but after testing across battery terminals there was no sign of any heat at all. Think I was confusing the current draw of the ABS pump with the plugs drawing current, so there's a reminder to be more diligent next time.

Ordered new set of NGK Y-924J and repaired manky porous 3.5mm rubber vacuum hose under manifold that I think is part of the EGR system.

Fitted glow-plugs and after rest of reassembly, gave fuel pump 3 runs to purge leak-off lines after disconnecting them, engine started immediately on first try, hurrah.

Tried one of the new plugs across battery before fitting, was red hot in 5 seconds so all my previous 30sec. preheats before starting were just a waste of time with the dead plugs.

Tried again after leaving all night, and after 5 sec. pause for preheat, started immediately.

The manifold was easier than I thought to remove and refit, so was well worthwhile for the extra ease of access, and checking electrical plugs and the vacuum pipe.