Maestro Turbo Ignition problems

[Jeff Turbo]

You would have thought that if the physical positioning of the crank sensor with the 620 / 800 turbo flywheel retro-fitted was an issue it might have been flagged up by the guys that have been down that road?

I don’t think that you can see the physical location of the sensor in relation to the reluctor ring even with the gearbox removed. The armature of the crankshaft sensor protrudes about 3/4 of its own length into the reluctor ring, thinking back from distant memory as it is visible on the 1.6 engine with VW manual transmission removed.

Regards Gary

Hopefully typed back in big for Jeff as he’s lost his spec’s

Splendid, I can see that lol

[Sussex Pete]

Currently having one, of the two aluminium sensor spacers I've got, milled down by 2mm, with some 20thou gaskets being made to suit in case I need to back it out a tad. Fairly sure that the tip of the sensor probe was sitting just above the surface of the reluctor ring, so the extra 2mm should be enough to create the magnetic field correctly. At least that is what we're hoping!

[thamestyres]

the depth of the sensor is or should be fixed... a small drill bit could be poked into the hole to measure the depth and compared with the sensor.. the later t16 sensor is compatible with the efi system but if memory serves the plug is different... I have interchanged the sensors in the past.. and I do currently run a wasted spark t16 system on my 8valve turbo.. regards ricky

[Sussex Pete]

BREAKING NEWS!!! I have a spark at the plugs! The problem came down to the crank position sensor being too short in relation to the flywheel I used. Effectively the tip of the sensor probe was in line with the top face of the reluctor ring, so not getting any magnetic field around it. Solution was to mill the face of the aluminium spacer by 1.5mm. This was enough to put the probe well inside the reluctor ring channel, but away from the bottom, so no chance of fouling and breaking.

The only thing left to address now (and this may well be my paranoia!) is oil circulation. Basically I have drained the sump because of the possibility of petrol contamination from earlier. I removed the oil filter and found that it was bone dry. Considering it pre-filled it when fitted, and all I've done since then is to turn the engine over on the starter for short bursts testing for a spark, I wondered why it was dry. I'm assuming that most has been absorbed into the element, as the filter is quite heavy.

To try an allay my fears, I have just used the starter for three 10-15 second bursts to see if any oil appeared from the oil fliter connection (with the filter still removed). So far nothing, other than a couple of small drips. So, do I bite the bullet and refit the oil filter after refilling it again, and then start the engine as normal or do I keep on with the 10-15 second bursts until oil is ejected from the oil filter connection before starting?

Finally after these engine runs on the starter, I'm getting a small oil weep from somewhere in the region of the rear gearbox mount - at least that is where its landing on the garage floor! Can't see where it might be coming from, nor really tell if its engine or gearbox oil and therefore how serious it might be. Anyone got any ideas about where I should be looking?

[Doctordiesel77]

Something like this http://www.ebay.co.uk/itm/UV-Dye-Tor...-/230754744531 will help you find and identify source of leak...not sure about oil circulation, but when I've rebuilt an engine, I fill a grease gun such as this. http://www.ebay.co.uk/itm/Groz-Lever...-/250537132750. with engine oil, screw the tube into the oil pressure switch hole and pump it into the engine, in theory it shouldn't fill filter, as filter has non return vavle...in real life it seems to fill everything...a bit messy , but you know it isn't starting dry..if you do not have a grease gun and want to do this, the cheapest one you can find will be good enough..

[mgdavid]

Yes, prime the pump as described above - or through the turbo oil feed outlet. Take the plugs out before you spin the engine over on the starter, it goes faster and gives the pump a better chance of self-priming.

[Sussex Pete]

BREAKING NEWS UPDATE!!! Completed the reassembly of all the parts I had removed to get at the crank sensor, oil filter filled and fitted, put another £5 worth of super unleaded in the tank, turned the key and she burst into life!!!!!!!! Running like a proverbial sewing machine, albeit with a fairly strong 1500-1800 idle speed. Oil seems to be OK and underneath is as dry as a bone. Can't find that weep from yesterday and hasn't come back after running the engine. No leaks or weeps from PAS, coolant, or fuel pipes so all looking good in that respect.

The only remaining concern now is that oil pressure warning light is not going out. The fact that the engine sounds like the oil is circulating as it should, I'm wondering why the light stays on. Looking at the wiring diagram, I can see that the switch forms the earth point for the HT side of the fuel pump relay. The light is fed from the output side of the inertia switch (I have confirmed this is down) and the input side of the fuel pump. As far as I can tell the pump is running fine when the engine is running. Be that the case, that doesn't explain why the O/P light is staying on, as I'm assuming that it is using the fuel pump to provide the earth. Anyone any ideas???

EDIT: Belay those comments above. Further investigation is showing that it may be the fuel pump relay as the engine runs for about 90secs then just dies. So, probably wasn't feeling the pump running after the engine started. And there are some damp patches on the turbo housing giving rise to smoke in the engine bay and another damp patch on the garage floor under the RHF lower arm rear mount of all places!

[Jeff Turbo]

Teething troubles, I'm guessing you have the original oil switch on the car? Also guessing that the fuel pump is priming? What do you mean by damp patches? Oil, water or petrol?

[Sussex Pete]

Teething troubles, I'm guessing you have the original oil switch on the car? Also guessing that the fuel pump is priming? What do you mean by damp patches? Oil, water or petrol?

Oil switch is new. Fuel pump is priming ok and reprimes as soon as engine dies. Damp patches at the moment look like oil. The one under the car looks like PAS fluid (just bled the system, which took three fill ups). The one on the turbine housing looks like engine oil. Will need to investigate these further, but will also need the car out of the garage to do it properly. V. limited access around the car at the mo

[Jeff Turbo]

You have an incorrect oil switch on the car then. Replace with the original. When running the pump current is supplied by the oil switch. There isn't a relay on it. Oil patches may just mean you need to tighten up a few things

[Doctordiesel77]

The oil switch is most likely the wrong one...I had the same problem with a diesel, where someone had fitted a normally open switch off an efi. I think all the 2.0 petrols were n.o., ie switch closes when oil pressure rises, opposite way to normal...ecu then works the light..I guess they did it so that if switch or wiring fails, engine stops.

[Doctordiesel77]

ha ha...you beat me to it Jeff

[Jeff Turbo]

ha ha...you beat me to it Jeff

Hah, great minds think alike

[Sussex Pete]

You have an incorrect oil switch on the car then. Replace with the original. When running the pump current is supplied by the oil switch. There isn't a relay on it. Oil patches may just mean you need to tighten up a few things

Jeff (and DoctorDiesel) I will bow to your better knowledge and certainly had read about the Turbo's having a different oil switch when I rebuilt the engine, BUT I checked the EPC rigourously (and again yesterday to be sure of this) and it shows the oil switch for the turbo engine is GPS133. This is a normal switch and the one I purchased is for a Mini but has a smaller spanner hexagon, as the switch it replaced had such a large hexagon it had gouged a groove in the oil pump when it had been tightened up. Just rechecking the EPC, GPS133 is used on every engine unless it's a 2ltr with air con and then its GPS136. On that basis I assumed I had bought the correct switch.

This pic is the wiring diagram for the fuel pump wiring on a Turbo engine. Fuse B8 (item 19) is an ignition controlled feed. The wire from the fuse connect to pins 87 and 65 of item 296. This is a latching relay (DRC1820 and has 5 connections) Pin 86 has the White /Brown wire (WN) that connects to the OP switch and hence to earth. A normal OP switch will break the circuit to earth once the 5psi pressure has been achieved, and is normally closed. Pin 87a on the relay has the Brown/Red wire (NR) that has come from the starter solenoid. Pin 30 has the White/Purple (WP) wire that connects to one side of the inertia switch (item 250) and from the other side using the White/Green (WG) wire to the fuel pump (item 41). The second WG wire on this circuit has come from the oil pressure warning light. This appears to show that with the ignition switched on, power to the pump is supplied via pin 85, to pin 86 and the closed OP switch. The relay is energised pulling the switch down, so that the pump is fed from the starter motor wire through the inertia switch and on to the pump. The fact that the OP warning light is connected after the inertia switch should indicate that when the fuel pump is running, the warning light is also earthed and hence stays lit! As soon as the engine starts and oil pressure is achieved, the relay is released so the pump is now fed directly from the fuse through pin 87.

This appears to be at odds to the description of pump operation for turbo models. Here BL wrote "With the ignition switched on, the fuel pump is isolated and receives its initial electrical supply on actuation of the starter soleniod. With the engine running the pump electrical supply is provided by the OP switch. If the oil pressure should drop, engine stalls or an accident occurs, the pump will be electrically isolated"

After writing this and thinking things through, I am now going to check that I have the Brown/Red wire connected correctly on the starter solenoid, as my pump is running all the time with the ignition switched on - which doesn't look to be right! If you guys have got any further ideas, or can correct my thinking/explanation I'll be glad to read them!

[carfix]

Hi Pete.

No more ideas but I admire your determination. I would have thrown my spanners at the cat and be in the pub by now !!!

Keep going, Ian