Chazza Posted December 30, 2013 Share Posted December 30, 2013 I am installing Megajolt onto my Sunbeam Alpine - if it helps, pretend it is a Series Land Rover - but I can't get a signal from the VR sensor. So far I have done the following and checked them all several times: * Machined and fitted the trigger-wheel and checked concentricity, which is 0 to + 0.1mm * Installed the sensor on its bracket and checked the air gap to the trigger-wheel, which is 0.6 to 0.7 mm. * Installed the sensor wires as per Trigger Wheel.com instructions - positive wire on the left looking into the harness plug. * Checked continuity on positive and negative wires to the EDIS4 connector plug, which was fine. * Removed the sensor from the car and checked the voltage with a multi-meter, whilst waving the sensor closely past an iron edge - result 0.1 to 3v and the same with a spare sensor. * Cranked the engine on the starter motor, while checking for voltage at pin 5 and pin 6 - result no signal. Pin 5&6 are connected to the VR wires in the correct location. * Cranked the engine with the EDIS4 installed - definitely no spark. Tried the spare EDIS4 but same result. So it seems to be a VR issue but I can't think of any more tests to do, or what I might have done wrong. The VR sensor is not exactly aligned with the centre of the trigger wheel but is only at the most 1mm offset. The wheel diameter is about 150mm. Perhaps the wires from the VR sensor should be connected differently to what TW says. If anyone can give me any useful advice at all, I would greatly appreciate it - this was supposed to be the easy part of the installation! Cheers Charlie Quote Link to comment Share on other sites More sharing options...
youngy Posted December 30, 2013 Share Posted December 30, 2013 why don't you just swap the wires , worth a go put pin 5 into 6 and 6 into 5 , if ours are the wrong way no spark !! Quote Link to comment Share on other sites More sharing options...
Chazza Posted December 30, 2013 Author Share Posted December 30, 2013 why don't you just swap the wires , worth a go put pin 5 into 6 and 6 into 5 , if ours are the wrong way no spark !! I had thought about it - so just swap them at one end? Cheers Charlie Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 30, 2013 Share Posted December 30, 2013 Yup, try it! Quote Link to comment Share on other sites More sharing options...
Jon White Posted December 30, 2013 Share Posted December 30, 2013 The 2 wires to the vr sensor are the wrong way round - one way round it works, the other way round it doesn't! Jon Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted December 30, 2013 Share Posted December 30, 2013 It's unlikely you'll see much going on with a multimeter. You need a scope too see the signal really. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted December 30, 2013 Share Posted December 30, 2013 Yup, as above Injectors PWM CTS and MAT don't care which way around, VR DOES ! The enclosed might help VR.pdfNige Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 30, 2013 Share Posted December 30, 2013 With a multimeter set to millivolts AC you might see something, waving a bit of metal on the end of the VR sensor should give some reading. I'm assuming your trigger wheel is made of ferrous metal and not some non-magnetic grade of stainless as someone once managed to do... Quote Link to comment Share on other sites More sharing options...
youngy Posted December 31, 2013 Share Posted December 31, 2013 Did it run yet ? Quote Link to comment Share on other sites More sharing options...
Chazza Posted December 31, 2013 Author Share Posted December 31, 2013 Thank you for all the advice everyone! The trigger wheel is definitely ferrous and attractive to magnets. Thank you for your installation link Nigel - it appears that I have wired the plug correctly, although the sensor I have is not straight like your one, but bent at the plug-end and the plug has to be rotated 180 deg. to engage on the straight one. This may or may not be the issue, but I am wondering if the new sensor is at fault. Trigger Wheels say to test the sensor with the engine cranking, so I will try that again today in case my previous testing of it was not done properly. Yesterday was spent outside raking up leaves for the bushfire season, plus I need another pair of hands for the testing procedure. Anyway, I will let you know what happens if anything; I will also unsolder the sensor wires and swap them, Cheers Charlie Quote Link to comment Share on other sites More sharing options...
Chazza Posted January 1, 2014 Author Share Posted January 1, 2014 Well; two of us finally tracked it down to the pins in the female connector at the VR sensor; when the plug was pushed onto the sensor one of the pins slid backwards inside the plug and didn't connect. So I had a look through my odds and sods and soldered two new pins on and the problem was solved. Still no spark yet, but I think the ignition leads I had made, don't engage on the coil terminals properly. Does anyone know off-hand what the diameter of the terminals inside the Ford 2nd generation coil are? The coil is the type with the rather tall terminal towers, Cheers Charlie Quote Link to comment Share on other sites More sharing options...
Chazza Posted January 21, 2014 Author Share Posted January 21, 2014 Update time and a stupid question; the engine is running on EDIS at idle although I think the 10 deg advance might be a bit too much for this high-compression Sunbeam engine - time will tell! So the stupid question is about writing the Megajolt ignition advance. Am I correct in saying that the value in the bins is the ignition advance in degrees? The axes on the table are in Kpa and rpm, as I am using MAP rather than a throttle sensor. The tables I have looked at on other types of engine, have the MAP starting at 0 or 10Kpa. Why the difference? Unfortunately my workshop manual only gives three different advances at three different rpm; so I will plot these on the table and then try and make a smoothish line between them. Is this the correct approach. I would of course borrow someone else's ignition map if I could, but I can't find one, Cheers Charlie Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 22, 2014 Share Posted January 22, 2014 What engine is it? And what dizzy? You should be able to find advance curve for the dizzy somewhere I would think... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 22, 2014 Share Posted January 22, 2014 Am I correct in saying that the value in the bins is the ignition advance in degrees? Plus or minus the trim value / how far off your trigger wheel is from perfect. Quote Link to comment Share on other sites More sharing options...
Chazza Posted February 8, 2014 Author Share Posted February 8, 2014 Plus or minus the trim value / how far off your trigger wheel is from perfect. OK; so the trim value in my Megajolt is 9 degrees. "Trim value" is the same as "static advance" in the manual - correct? The manual says at 2500rpm the centrifugal advance is 24 deg. plus the static advance of 9 deg. = 33 degrees. 33 degrees is the value to put in the appropriate bin then? Thank you for help, Capt. Thicko Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 10, 2014 Share Posted February 10, 2014 OK; so the trim value in my Megajolt is 9 degrees. "Trim value" is the same as "static advance" in the manual - correct? Which manual? Trim value is the difference between the trigger wheel's position and the "perfect" alignment, and is basically there to correct the small error you will always have in aligning the VR sensor / trigger wheel perfectly. Your advance is all done in the ignition table & cranking settings. The trim value is just there to make sure that the number you put in the table is the number that actually happens at the engine. Quote Link to comment Share on other sites More sharing options...
Ex Member Posted February 10, 2014 Share Posted February 10, 2014 You are supposed to set the trim value with a timing light. Quote Link to comment Share on other sites More sharing options...
Chazza Posted February 10, 2014 Author Share Posted February 10, 2014 I was referring to the car's workshop manual in my earlier post. It sounds as if I am confusing the trim angle, with the static ignition advance set on a distributor at idle. So EDIS defaults to 10 degrees BTDC. If the timing light shows that it is actually 9 degrees BTDC the trim angle is adjusted on the computer. True or false? At the moment the timing light shows the mark oscillating, which someone on another forum suggests could be because the bins around idle need adjusting. Any ideas? I understand what the crank advance setting is when setting up the table, but what advance do you chaps use? Cheers Charlie Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted February 11, 2014 Share Posted February 11, 2014 As fridge says "Trim" = adjustment for the timing being out either way Your spark table should purely reflect the spark advance curve for the engine, on a scale of 0-xxx RPM and 0 - 100 KPA this gives the WOT advance and then the vacumn advance below 100 KPA Edis runs at 10 degrees, the ECU then "Overerides" this 10 degrees and says "Non - use the table here instaed of 10 degrees" HTHNige Quote Link to comment Share on other sites More sharing options...
Chazza Posted February 11, 2014 Author Share Posted February 11, 2014 ... the ECU then "Overerides" this 10 degrees and says "Non - use the table here instaed of 10 degrees" HTH Nige Ah ha! Thank you Nige didn't realise that. It is surprising after how much reading I have done on this subject, how something as simple as your statement has not been mentioned before! Anyway; more good news, a chap in America has sent me his 12 x12 table, which has given me all sorts of useful info for writing my own table. A big thank you for everyone's contribution, Cheers Charlie Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 11, 2014 Share Posted February 11, 2014 EDIS defaults to 10deg until told otherwise by the ECU. The MS works out advance based on value in table + trim angle, so when the engine is running the advance number being sent to the EDIS is whatever is in the table + the trim angle. You need to adjust the trim angle so the REAL timing as shown with your timing light is the same as whatever's in the box on the table. It's easier to get the trim angle dialled in if you set all the boxes in the "idle" bottom corner of the map to the same value, that way you know it's not jumping around as the engine idles. After that, reload your proper table (you did save it, right?) Quote Link to comment Share on other sites More sharing options...
Chazza Posted February 11, 2014 Author Share Posted February 11, 2014 Thanks Fridge! Yes, I have been saving, but because I constructed my own table from a blank page, there has been a lot of estimating and guess-work going on, Cheers Charlie Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 11, 2014 Share Posted February 11, 2014 One wrinkle is that the megatune "advance" gauge shows the total number (advance + trim) not the "real" value (advance) that you want. It's possible to change it, don't ask me how. Quote Link to comment Share on other sites More sharing options...
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