Escape Posted February 18 Author Share Posted February 18 Many thanks to @elbekko, not just for getting the scope but mainly for pushing on with the troubleshooting. I always assumed (yes, I know what that stands for...) if the VR was incorrectly wired, there would be no clear signal and thus no spark. Combined with the fact I knew the pin out of the sensor used and wired it accordingly, swapping the wires in the sensor connector seemed all but impossible without doing damage and most importantly, this same set-up actually got a P38 running (way back in '19), I had convinced myself it had to be something else. After testing with the scope we did another log with the MS. And that gave a much better result, no missing teeth in wrong places, all nicely spaced. As Ben said, it was already past midnight by then, so I didn't think it a good idea to push on much longer. The plan for next time is to verify coil A is firing at the correct position, by hooking up one channel to the VR sensor and the other to the coil driver output. We can always double check with the timing light as well. Once coil A is confirmed, we'll do the same for B, C and D. And then we can finally try to fire her up. Another mate has given me a deadline, to join him on a camping and green laning trip end of August. If the engine runs, that should be very much possible. We might even find time to look at the winch as well. 🙂 Filip 3 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 18 Share Posted February 18 There's a pretty good explanation here: http://msextra.com/doc/ms1extra/MS_Extra_Basic_Configuration_Manual.htm#desvr The simple version is if you swap + and - on the VR the "missing tooth" actually creates two "missing teeth" in the signal and confuses the ECU's timing: The longer explanation is the ECU is looking for a "zero crossing" in the signal going in one direction - for example positive to negative - which yes, you can change inside the ECU or by swapping the sensor wires, if you get them the wrong way round you get two crossings about 1.5 teeth apart which looks to the ECU like it got one less regular tooth on the wheel and then the missing tooth happening twice, so now it doesn't know where TDC is anymore. BTW for those that don't have a picoscope or similar, there are plenty of very cheap "mini-DSO" kits on eBay from China that are more than good enough for diagnosing stuff like this on a car and cost from about £10 up. This one's a whole £28: https://www.ebay.co.uk/itm/296020811621 3 Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 27 Share Posted February 27 Not sure if it's worthy of an update yet or not. We continued yesterday. Hooked up the scope to the VR, and then the coil output, one by one. Wrote it down. It looked fine. Tried starting. Nothing. <insert despair> Go over everything again. Realise I wrote it down wrong. Realise wrong assumptions have been made from the start. <more despair> But there's a sliver of hope. What it comes down to, is that the MS definition of coil A, B, C, D isn't the same as the LR definition of said coils. And for some reason we never realised this, and just kept talking about coil letters, not cylinder numbers. The result is that MS is firing order ABCD, but as the LR coils are they should go ADCB. We'll have a stiff drink, rewire, revalidate, have another stiff drink, and try starting again. The mindf*ck isn't improved by the MS having output B&C swapped internally, the wiring loom going GEMS -> GEMS to Bosch coils adapter -> Bosch coils. But we'll get there. 4 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted February 27 Share Posted February 27 Well, it is progress Quote Link to comment Share on other sites More sharing options...
Escape Posted February 27 Author Share Posted February 27 It was progress, definitely. Most importantly, we now know where the problem is situated. Which is half way to a solution. I'm also starting to wonder if this is why our previous attempt to get a P38 running with MS, almost 10 years ago, never succeeded. We knew (assumed) it was timing, but never figured out what could be wrong. I'll do the rewiring tonight, definitely have a stiff drink and maybe even try turning the key again. The day has started out pretty good already (despite taking the train), as we got a Matra M530 that hadn't run in 40 years through MOT! 2 Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 27 Share Posted February 27 11 minutes ago, Escape said: I'm also starting to wonder if this is why our previous attempt to get a P38 running with MS, almost 10 years ago, never succeeded. We knew (assumed) it was timing, but never figured out what could be wrong. I have a feeling it may well have been, yes... Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted February 27 Share Posted February 27 14 minutes ago, Escape said: we got a Matra M530 that hadn't run in 40 years through MOT! Oh, now that's not a make you hear much of any more, Matra Rancho anyone? 2 Quote Link to comment Share on other sites More sharing options...
Blanco Posted February 27 Share Posted February 27 9 minutes ago, Bowie69 said: Matra Rancho anyone? Crumbs, that does bring back memories, ... wouldn't mind one now as a classic runabout 😊 Quote Link to comment Share on other sites More sharing options...
Escape Posted February 27 Author Share Posted February 27 28 minutes ago, Blanco said: Crumbs, that does bring back memories, ... wouldn't mind one now as a classic runabout 😊 Crumbs is pretty much what's left of most by now... I do admit they looked good, not sure I could put up with it as a daily. The M530 is a very nice drive, almost sporty. The Bagheera not so much. I've not had the privilege to drive a Rancho, but don't expect too much either. Quote Link to comment Share on other sites More sharing options...
Blanco Posted February 27 Share Posted February 27 2 minutes ago, Escape said: I've not had the privilege to drive a Rancho 1440cc of raw power IIRC, hardly what you're used to 😁 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 27 Share Posted February 27 45 minutes ago, Bowie69 said: Oh, now that's not a make you hear much of any more, Matra Rancho anyone? I had the toy car of one, always thought it was kinda cool. More than a little Discovery about the stepped roof too. Glad you've worked out what the problem was - you are by no means the first to be caught out by a perfectly sensible assumption during an MS install! The Ford coil packs have cylinder numbers on them but of course (again) Ford's idea of cylinder numbers & firing orders may not be the same as whatever engine someone's bolting them to... The VR polarity thing is a tricky one because as you've found out, it WILL run, just not very well... EDIS has the good grace to be pretty black & white, it will either run perfectly or not at all while the MS code will give it its best effort even when things aren't right. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted February 27 Share Posted February 27 Just now, FridgeFreezer said: I had the toy car of one, always thought it was kinda cool. More than a little Discovery about the stepped roof too. Yep..... but these days this is a problem: 1 minute ago, Blanco said: 1440cc of raw power IIRC, hardly what you're used to 😁 Perhaps a nice French V6 would bolt in there instead Quote Link to comment Share on other sites More sharing options...
Escape Posted February 27 Author Share Posted February 27 I'm sure a Rancho with a PRV has been done. Now, a Rover V8, that would be something. And a driven back axle of course. 😁 Don't give me any ideas!!! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 27 Share Posted February 27 Reckon a Rancho would want something smaller and peppier, a 2.0 4-pot or something. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted February 27 Share Posted February 27 Only 1140Kg apparently.... something aluminium and revvy sounds good to me 1 Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 28 Share Posted February 28 Ok, someone please save our sanity. The Bosch uses two of these coils: https://www.speedingparts.eu/p/engine-management/engine-control/ignition/ingnition-coils/bosch-motorsport-ignition-coil.html Which should work like this: Now, when looking at the plug diagram in RAVE, it says this: Which would make the layouts of the coils like this: At least, that's what all the wiring diagrams claim: But that doesn't make any sense. The two coils are identical, just rotated 180 degrees. So KB (1&6) should be on pin 1, not pin 3. All wiring and plug wire locations check out with my running Bosch P38... I just double checked with the D2 RAVE, and it's identical. What the *beep beep beep beep **** beep*? Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 28 Share Posted February 28 Ok now hold up. The D2 electrical diagram agrees, but not the ECM pinout... RR: D2: And that would make it correct... Motherf*ckers. Quote Link to comment Share on other sites More sharing options...
Escape Posted February 28 Author Share Posted February 28 I just discovered the same thing... That's the better part of an evening head scratching because someone made a mistake in the wiring diagram in RAVE and only corrected it in one place (for another car). Ooh well, now we know and can proceed. 🙂 Quote Link to comment Share on other sites More sharing options...
Escape Posted March 1 Author Share Posted March 1 After another rewire we finally seem to have the timing right: no signs of misfires and the engine came alive at last. Not running yet though, she fires and immediately dies again. Which we're hoping is just the air and fuel delivery and settings at idle. I continued with some other wiring and tidying up bits. Starting to look like a car again at last! She's now ready to give it a try in earnest and get the camshaft run in. Keep you fingers crossed on Sunday! 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 1 Share Posted March 1 Could also be the fuel pump not running after initial fire? Quote Link to comment Share on other sites More sharing options...
Escape Posted March 2 Author Share Posted March 2 yes, it could be the fuel pump, I haven't tried jumping the relay yet while starting. It definitely primes when turning the ignition on and runs when jumpered (as a test). 1 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 2 Share Posted March 2 On 3/1/2024 at 3:02 PM, Bowie69 said: Could also be the fuel pump not running after initial fire? If the pump is under MS control it will run the pump whenever it sees ignition events and cutoff 2 seconds after the last one. Quite usual for an install not to idle on first fire, I would not start making drastic changes it will just be the tune. Quote Link to comment Share on other sites More sharing options...
Escape Posted March 3 Author Share Posted March 3 The pump is indeed under MS control and primes as expected when the ignition is turned on, so that should be OK. I wasn't planning on any drastic changes, just want to check things as best as we can before continuing. There is no idle air control as of yet, so I should probably keep the throttle open just a bit. Anything on the fuel side we need to check? It's running either the map you provided me or the most recent one from Quentin's 4.6 classic. The latter should be a very good base as he is using the same Bosch injectors and fuel pump (running higher pressure). Hopefully good news by the end of the day! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 3 Share Posted March 3 1 minute ago, Escape said: The pump is indeed under MS control and primes as expected when the ignition is turned on, so that should be OK. Was only suggesting fuel pump I case it went dead when cranking, ignition lives have a mind of their own sometimes. If fed from permanent then all good! As F says, very common to stall on first start, especially with a new tight engine. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 3 Share Posted March 3 With no idle control you'll probably need to feather the throttle from cold to keep it running as there's no other source of bringing the idle up. Weirdly my 109 has always needed a single blip at startup and then idled perfectly with no idle control at all, but the 127 won't do the same. 1 Quote Link to comment Share on other sites More sharing options...
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