Ken Dunkley Posted October 10, 2017 Report Share Posted October 10, 2017 So i had a strange thing happen tonight after changing my coil . I run a msd streetfire ignition box through a dizzy with an old oil filled coil . It ran very well just thought id upgrade the coil to an msd non oil filled high output coil . Straight forward swap making sure pos and neg wires are correct and good to go - i thought . It just barely started - loaded up and stopped . Connected my laptop to the ecu and it would not stay online as i tried to start the engine . If it did start it over fueled to hell and stopped . Put the old coil back on and boom - all good . I have a atom g4+ in a center console and the msd ignition box is also in the console . The coil is in the engine bay at the front of the engine . I was advised to run the whole dwell table at 3 ms and up till the coil change starting and running has been excellent . Any ideas why the ecu would keep disconnecting from the laptop and not run properly when trying the new coil ? Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 10, 2017 Report Share Posted October 10, 2017 Not really sure how it would affect PC Comms, but can you confirm that you have the spark edge set to rising. Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 10, 2017 Author Report Share Posted October 10, 2017 I checked and yes set to rising . Ill check HT lead and have the coil checked next . I guess it could be faulty . Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 17, 2017 Author Report Share Posted October 17, 2017 So turns out its not a coil problem -its a trigger error . I have a VR crank angle sensor on a 60-2 wheel - Sensor is a denso oem type from NZEFI as is the trigger wheel . The engine has been running fine with no trigger errors . Over the last few runs it developed a slight miss and when i hooked the lap top up it showed -REV LIMIT ACTIVATED - I didnt think much of it until this weekend . Drove around the block logging and noticed trigger 1 errors counting up and odd rev spikes over 6000 even though i was just tooling around . Ive just changed the crank sensor with a new one . I did an ohms test on both trigger sensors and the wiring back to the ECU plug . All tested perfect . The trigger wheel is 6 months old . Maybe done 1000 km of driving on it and its clean . Test ran it and still showing trigger 1 errors counting up and missing etc . Any ideas ? Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 17, 2017 Report Share Posted October 17, 2017 So did you only get trigger errors since changing to the new coil? From memory you have an Atom with no triggerscope function, do you know anyone with a storm or higher ECU that you can borrow to do a triggerscope (your dealer may do this)? Or maybe someone with a standalone oscilloscope? Where abouts are you in the world? Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 17, 2017 Author Report Share Posted October 17, 2017 I tried the new coil because the engine developed a small miss . I recall now though the - RPM LIMIT ACTIVATED warning showing on the laptop a couple of times before i changed the coil and i never checked why . I now suspect that it was the trigger errors . After trying the new coil and it not running i went back to the original and it ran fine for a couple of hours driving ( albeit with a small miss ) . This Week end just gone it wont run properly now . The engine will start - Just and run - Just . With trigger errors counting up the longer it runs . The ECU is a G4+ if that makes a difference . And no i dont know anyone with the ecus you mentioned . Do you suspect it could be the ECU ? Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 17, 2017 Report Share Posted October 17, 2017 55 minutes ago, Ken Dunkley said: And no i dont know anyone with the ecus you mentioned . Do you suspect it could be the ECU ? No it is obviously the trigger so I want to see a trigger scope but If my memory serves me correctly you only have an atom which doesnt have a trigger scope. Thats why I asked about borrowing one that has a trigger scope. So where abouts are you? Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 17, 2017 Author Report Share Posted October 17, 2017 Im in Rotorua. What makes you think its the trigger when ive replaced the sensor and tested the wiring up to the plug . ? Quote Link to comment Share on other sites More sharing options...
Ducie54 Posted October 17, 2017 Report Share Posted October 17, 2017 The msd HVC coil wiring dia shows a ground strap from one of the coil body bolts. Not sure if that would help. Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 17, 2017 Author Report Share Posted October 17, 2017 Thanks Ducie - When i sort this trigger issue ill double check - Quote Link to comment Share on other sites More sharing options...
Woody Posted October 17, 2017 Report Share Posted October 17, 2017 Its possible maybe that the polarity is wrong on the VR sensor , thats probably why Adam asked for a scope check .. HTH Keith Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 18, 2017 Author Report Share Posted October 18, 2017 Woody . The engine has been running fine for almost a year with no trigger errors . The fault has just developed over a short period of time ( a few hours running ) . I had not changed anything up till this week when I changed the crank sensor because I was getting trigger errors . The new sensor didn't fix the issue . Oh that's right I changed the coil because of slight missing . Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 18, 2017 Author Report Share Posted October 18, 2017 I reset the sensor gap to 1/2 a mm and ran the engine . Seems to run ok when cold and get worse when fully warm . At which point the trigger errors clock over ( getting over 100 in a minute of running ) Also tried trigger filtering on levels 1 - 2 -3 and 4 with no difference . Quote Link to comment Share on other sites More sharing options...
Adamw Posted October 18, 2017 Report Share Posted October 18, 2017 Im working with Ken in the background to get a triggercapture done on his car. We will update this thread for anyone's interest once we have done that. Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted October 26, 2017 Author Report Share Posted October 26, 2017 So finally got this sorted . Adam from Link loaned me a higher spec ecu that had a trigger scope function and after scoping my engine it clearly showed a trigger mag pickup was to blame for my problem . Thanks Adam for your help ( and patience ) - Cheers - Ken . Quote Link to comment Share on other sites More sharing options...
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