hackish Posted July 31, 2009 Share Posted July 31, 2009 I've been trying to tune a customer's EDIS/MSnS system. He did the engine build and wiring and I've gotten it to start but the engine runs like something that's off a tooth on the cam. I put a timing light on it and found the timing is quite retarded. It's an L28 turbo swapped into an older 240z. So I took the 36 tooth wheel and lined it up as per BRAAPZ's directions - used a rod in cyl1 to find TDC and counted teeth: I left the MS settings at skip 3 teeth and found that -10 timing will allow it to start. The car runs really poorly, backfiring a lot and the revs like it's off by a tooth on the cam. So I hooked up a timing light and despite asking for -18 degrees timing at idle I found cylinder #1 is actually firing somewhere around 30 degrees ATDC. The customer removed the stock timing marks so there is no real way to be exact but I'm wondering what suggestions can be given to solve this problem. I can try unplugging the MS and just blindly adjust the trigger wheel until it shows about 10 degrees BTDC. That's about all I can think of at the moment. thanks -Michael Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted August 3, 2009 Share Posted August 3, 2009 Some of the settings you mentioned aren't normally used with EDIS. Is this a crank triggered distributor setup? Could you post the MSQ (tune) file out of the unit? Quote Link to comment Share on other sites More sharing options...
hackish Posted August 3, 2009 Author Share Posted August 3, 2009 Crank triggered EDIS. To save time here are the relevant ignition settings. I'm not sure where the client got the basemap - the startup fuel and ignition map were completely wrong. Quote Link to comment Share on other sites More sharing options...
hackish Posted August 3, 2009 Author Share Posted August 3, 2009 Quick update. I just went through and verified the owner's wiring job. The coils appear to be wired correctly. I'm going to take the coil pack off just to make sure he didn't reverse all the wires on the connector. I also installed a butt connector on the PIP and SAW plugs so I can unplug one of them and force the EDIS into limp mode. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted August 3, 2009 Administrators Share Posted August 3, 2009 For VR sensor clocking reference, that picture of my crank trigger above is with the #1 cylinder at TDC compression stroke, VR sensor, exactly 6 teeth counterclockwise of the missing tooth. With the SAW signal disconnected, that should be an ignition timing of 10 degrees BTDC regardless of what setting you have set in MS and regardless of what RPM the engine is running at, (puts EDIS in limp home mode, 10 degrees BTDC!) If you unplug the the jumper plug connector that is integral in the EDIS wring harness, (if you do not have that plug, just disconnect your SAW wire to achieve same result.), what is the ignition timing then? It should be 10 degrees BTDC indicating the trigger wheel to VR sensor clocking is correct! 1) If after disconnecting your SAW signal the ignition timing is a solid 10 degrees BTDC then your issues are in your MS settings. 2) If it is still too far retarded, then your VR sensor to trigger wheel clocking is off. It is off by the number of degrees it would take to get the timing light to register 10 degrees BTDC. Looking over your MS files, most of which I do not understand, (different version of MS-nSe?), what I do recall is that when using EDIS and selecting EDIS in the menus, MS didn't allow me access to any of the dwell settings etc, (grayed out, could not input any settings for dwell). Also, I seem to recall that EDIS prefers the falling edge, not the rising edge, but I could wrong there. Matt?... For what its worth, here were my MS settings for EDIS-6 that worked on my set up; Quote Link to comment Share on other sites More sharing options...
softopz Posted August 3, 2009 Share Posted August 3, 2009 ok so Iam that customer. To clarify this is an ms2 system not msns(ms1) The wheel is correct however this is really confusing. Because my timing marks were removed when isntalled the vr sensor, however my brothers setup has the timing marks on the other side?! so I decided to get the light showing in that proximity (like my brothers car). And the car fired up ran okay not great. We have some issues that are quite strange. for example. The car seems to run only on 3 cylinder but sounds like more which is strange (verified by removing Fuel injector plugs and narrowing it down to dead cylinder and with timing light) So it seems like the bottom row of terminals ABC of the coil pack are the ones that are causing weak spark. It doesnt show with the timing while engine is running. Which are cylinder 246 according to the megamanual looking at the ford coil pack with connector at the bottom from left to right terminals ABC in order. And the firing of therminals are ACB so I have my spark plug wiring like A=1&6 C=5&2 B=3&4 so why are the bottom terminals weak. Another issue is I upgraded to a zx alternator and I got this guys little adaptor that includes the diode. Apparently that got real hot and this is affecting the way the engine is running. Could be the cause of the terminal problem I wont know for sure till I get a different coil or fix this alternator issue. I thought I needed that adaptor cause I read that the car wont turn off(if switched off) But then I thought Iam running FI not carbs now and I got MS2 and everything is fed of the ignition switch so if I killed the ignition switch it will definatly shut the car off. So thats where this thing stands right now Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted August 3, 2009 Share Posted August 3, 2009 The diode is so that the alternator does not back feed the ignition wire, and keep the ignition circuit powered up. Has nothing to do with what engine control you are using. Quote Link to comment Share on other sites More sharing options...
softopz Posted August 3, 2009 Share Posted August 3, 2009 exactly so if you dont have it on a original carb car it will stay on. isnt that right? so why is it so hot that it melted the wire?! with that plug/adaptor/diode there it shouldnt have had any problems isnt that a correct assumption? how about the bottom half of the coil? should it spark just as liek the top towers? Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted August 4, 2009 Share Posted August 4, 2009 Again, it doesn't matter if it's carb or EFI, the back feed happens on the same circuit that powers up the EFI, so regardless of induction/engine control with the diode the car will stay running. Not ALL alternators are like that, just some, and the 280Z/X alternator may be like that, personally I used a GM alternator in mine, I didn't need to add a diode. I can't explain why the wire would get that hot, I didn't make the adaptor harness nor see it first hand. Yes, both sides of a two tower coil should have the same spark intensity, or at least so close that we wouldn't be able to tell without using some test equipmet to measure spark energy. Quote Link to comment Share on other sites More sharing options...
hackish Posted August 4, 2009 Author Share Posted August 4, 2009 If there is a problem with the EDIS ignitor then maybe it's not giving consistant dwell on the coils. I will attach a scope to it and see what I can find. We mechanically found TDC on the engine via a TIG rod in cylinder1 and via the cam lobe. It is definitely firing way past TDC. Originally I suspected it was about 90-100 degrees too late so I rotated the coils by one. This gave a proper spark at the correct time but it doesn't explain why it does not work as advertised. Car ran well like that but one morning the battery was dead and it wouldn't fire up again. We ended up setting everything back to the way it was before and spent almost an entire day before it ran again. I verified the coil to ignitor wiring and it appears correct. From left to right with the plug on the bottom they are supposed to be A,B,C. Quote Link to comment Share on other sites More sharing options...
z-ya Posted August 10, 2009 Share Posted August 10, 2009 Every time I think that the problem is the EDIS module, I'm wrong. I have not seen one fail. This is how I would approach this problem (I am assuming that cam timing is OK and you have a good battery): 1) Get cylinder #1 as close to TDC as you can (TIG rod, screw driver, whatever) 2) If the timing tab doesn't align with a mark on the damper, make a mark on the damper that aligns with the timing tab (I use leftover silver touch-up paint that shows up nicely with a timing light) . 3) Disconnect power from fuel pump or remove the injector plugs. 4) Disconnect SAW signal from MS and crank engine. It should show close to 10 Deg advance. If it is close to 10, then you are OK for now. If it is way off, the VR sensor location is wrong and should be corrected. 5) If the timing is off less than +-5 Deg, then you can calibrate it using the trim angle settings in MS once you have the advance working. 6) Connect the SAW signal and now you should see the crank timing with the light (+- whatever offset you saw in step 4). If you don't see the timing change, the advance is not working. If the timing did change from step 4 then adjust the trim angle in MS so that the timing you see with the light matches the crank timing setting in MS. 7) Now that your timing is calibrated, reconnect the fuel pump and or injector connectors and start tuning! If you can't get the advance working there are plenty of threads here that can help you. Pete Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.