Panic Stations!

[Jeff Turbo]

Thanks for your feedback guys!

The thinking behind stopping the fuel flow was to try and isolate the problem causes. I removed fuse B8 (15Amp) which according to the BL Manual is the one controlling the green feed to the fuel pump relay. Certainly without it in, I don't hear the fuel pump running with the ignition on - which is why I raised the question about where enough fuel could be coming from to be seen escaping in large spurts from the spark plug holes when spinning the engine over on compression tests. I would have thought the bores would have been almost dry once the major exodus of petrol happened after the first hydraulicing incident.

As for all the other variables in the fuel system, following Jeff's advice I have changed the fuel feed and the carb vent valve pipes over, so now fuel should be going into the float chamber rather than straight down the venturi. The carb itself has been fully rebuilt by Southern Carburettors including a brand new autochoke fitting, so I would hope that a sticking float is not manifesting itself; the fuel pressure regulator is brand new, so again I would expect it to have been correctly set at the manufacturer.

I will see if I have a spark, using the "spark plug held to the block" test. If that is successful, I would then move to refitting all the plugs and see if the engine still spins over (still without the fuel pump running). If I don't get a repeat of the hyraulicing issue, then I'll drop the oil and fill with fresh and a new filter. Then I'll allow the fuel pump to run and see if the engine will start.

One other thought I had, relates to the fuel tank piping. As these were removed by the "amateur mechanic" with no notes or records, I have reconnected it based purely on what I see and common sense, as in the large pipe on the tank was connected to the inlet of the fuel pump as the pipe diameters are the same, then the small pipe on the tank is connected to the spill return pipe, again because pipe diameters are the same. Was my logic in this correct, or do I need to change these round? None of the manuals (Haynes or BL) give anything to help in this matter.

Yeah the piping in the tank is correct Pete, maybe worth checking to see if the return is clear though while you're at it. Just blow down it

[Mike Brock]

Yeah Jeff I know what you mean - stop fuel going in then then once excess fuel is exhausted - then sort the problem. I was thinking further along the line as to why large quantities of fuel is pumping into the engine. To that point we agree fuel is getting to the carb from tank - I would check fuel pressure - but remove carb as you don't want raw fuel going into the engine or you'll just be going round cycles. You need to determine if float valve sticking or perhaps the rubber O-rings on choke mechanism spindle? Your going to get lots of fuel spillage so a bucket under the carb doing those tests. I wouldn't assume anything to be honest.

[Sussex Pete]

Real progress today. Now at the stage where fuel pump is working, no visible leaks across the feed or return systems. Plugs out and spinning engine over with only vapour being emitted from cylinders. No spurts of fuel at all. Plug check onto block was giving no spark. Followed ECU tests from Haynes manual and that all looks OK, except I have zero resistance across the primary windings on the coil. Looks like I need a new one Is there anything special about the coil for the Turbo or is the standard GCL143 (or equivalent) OK?

[Jeff Turbo]

You wanna borrow these Pete?

[Sussex Pete]

Thanks for the offer Jeff. As SWMBO and I are off on a 10-day break next Friday, this seems like a convenient point to stop work on the engine and I'll resume when I get back. In the meantime, I'll get another coil and if I don't get a spark at the plugs when that is fitted, then I would like to take you up on your offer. I'm thinking towards getting it ready for MOT at the end of next month so I can enjoy using the car for the summer and autumn at least.

[ian drew]

Sounds like you've had your fair share of problems there Pete. One thing that I think has been causing you problems is that the fuel pump WILL run without the fuse when turning the engine over, there is a bypass when cranking for some reason. The inertia switch is also bypassed. I found this out the hard way when my car would start and always die after about 50seconds. The problem turned out to be simply the inertia switch was up but enough petrol was pumped during cranking to fill the float chamber and keep it idling for 50s.
Good luck with the rest!

Ian

[Sussex Pete]

OK, guys! Thinking caps on please! Having purchased and fitted a new electronic ignition coil, GCL143 equivalent, I am still not seeing a spark at the plugs, nor at the end of the HT lead from the coil. I am also still seeing 0 ohms across the new coil + and - terminals with the ignition switched on. My tests so far have been to check across pins 9 and 12 of the ECU wiring connector. Battery voltage seen with ignition on. Then tested pins 10 and 12 of the ECU wiring. Again battery voltage seen with ignition on. If there is no spark, does this point to a duff ECU? Any other ideas about what could have failed or what I could test to prove OK. Getting a tad frustrated that I have a complete car, that is refusing to play ball and start the engine!

[Jeff Turbo]

Crank sensor and I've answered you pm Pete

[Sussex Pete]

Having received the ignition analyser and fuel management testers from Jeff, I followed instructions and can now confirm that the static and dynamic tests all passed with flying colours! Crank, knock and temp sensors all OK. Fuel tests also passed without any problems. Came down to the ignitions tests, and still not getting any spark from coil HT lead to block. The remedy list was HT Lead (New set fitted during rebuild), Coil (replaced last week) and if still no spark then suspect ECU.

Looking at my EPC, I see that on the Montego Turbo there were 3 types of ECU specified, based on VIN number. As mine is fairly late, presumably I should be looking for the latest ECU as well. Checked MGRoverPartFinder and none are showing up. Rimmers have the middle one, but at £300+£100 surcharge I think I will give that a miss!

Before I go out and spend a wad of cash, are there any other ideas about what might have failed and can anyone provide accurate info about the ECU I need.

[Doctordiesel77]

Double check that the new coil is not faulty, best way is to test it on another vehicle, if this is not possible, then fit ht lead to coil, with spark plug in, connect plug to the block, disconnect lt leads, connect a +12v supply to the + side & flash an earthed wire off the negative side, you should get a spark from the plug...be very careful when you are doing this, lethal voltages may be present on both sides of the coil, so hold the wire in insulated pliers... I mention this because I can remember spending a saturday morning replacing every single component in an ignition system, apart from the one component that had been replaced the week before....it was the culprit in the end.... If the ecu does end up in the frame, then this might be a useful link https://www.atpelectronics.co.uk/c/r...o-ignition-ecu I've never used them, but whoever gave me the link in the dim & distant past must have thought they were ok...

[Jeff Turbo]

Having received the ignition analyser and fuel management testers from Jeff, I followed instructions and can now confirm that the static and dynamic tests all passed with flying colours! Crank, knock and temp sensors all OK. Fuel tests also passed without any problems. Came down to the ignitions tests, and still not getting any spark from coil HT lead to block. The remedy list was HT Lead (New set fitted during rebuild), Coil (replaced last week) and if still no spark then suspect ECU.

Looking at my EPC, I see that on the Montego Turbo there were 3 types of ECU specified, based on VIN number. As mine is fairly late, presumably I should be looking for the latest ECU as well. Checked MGRoverPartFinder and none are showing up. Rimmers have the middle one, but at £300+£100 surcharge I think I will give that a miss!

Before I go out and spend a wad of cash, are there any other ideas about what might have failed and can anyone provide accurate info about the ECU I need.

Does the coil light come in on the lucas test equipment on both tests?

[Sussex Pete]

Does the coil light come in on the lucas test equipment on both tests?

Yes Jeff. That to me, says the wiring is OK, not necessarily the coil itself. I'm going to follow DD77's advice and try the coil "bench test", as I was concerned that even the new coil was showing zero ohms resistance on the primary windings, just like the one that it replaced.

[Jeff Turbo]

Yes Jeff. That to me, says the wiring is OK, not necessarily the coil itself. I'm going to follow DD77's advice and try the coil "bench test", as I was concerned that even the new coil was showing zero ohms resistance on the primary windings, just like the one that it replaced.

That means the coil is ok to me, shows there's power to and from it or it wouldn't light up, have you tried testing the rotor arm?

[Sussex Pete]

That means the coil is ok to me, shows there's power to and from it or it wouldn't light up, have you tried testing the rotor arm?

When I did the original spark test, I checked the plug to block via its plug lead. With no luck there, I then checked the coil lead from the distributor cap to block. No spark there either. I took this as ruling a faulty rotor arm out of the problem. Also, this was using the new coil. As these coils are supposed (according to specifications) have about 0.7 to 0.8 ohms resistance and I was seeing zero with both the old and new, I was having doubts as to whether they were OK or if this was a symptom of a failed ECU.

[Jeff Turbo]

Do you have an alternative ecu Pete? Any will do to check if the existing is dead