Rydere12 Posted July 14, 2022 Share Posted July 14, 2022 Does anyone have any experience putting megajolt on a fuel injected engine. Link to comment Share on other sites More sharing options...
Nick Jones Posted July 14, 2022 Share Posted July 14, 2022 Welcome! When you say "fuel injected" do you mean Lucas PI - or something else? Assuming you even mean Triumph? If PI, it's not really any different from putting it on a carb'd engine with the possible exception that you may not get a great vacuum signal for the load sensing. In that case you'd need to add a throttle position sensor which isn't all that straight-forward on the PI throttle bodies/linkage. Give us some more clues.... what car etc.... Link to comment Share on other sites More sharing options...
Rydere12 Posted July 14, 2022 Author Share Posted July 14, 2022 Megajolt to a Boscl L-Jetronic Fuel Injection on a 1981 Fiat Spider. My issue is where/how to pickup a signal going to the cars ECU that will trigger the injectors to open. The original distributor/coil ignition system is relpaced with the Megajolt/wasted spark ingition system. The signal wire originally came off the coil which has been removed/replaced with the Megajolt system. Link to comment Share on other sites More sharing options...
JohnD Posted July 14, 2022 Share Posted July 14, 2022 The online info about Megajolt is FULL of how to set up the toothed wheel on the crankshaft. Read that first? JOhn Link to comment Share on other sites More sharing options...
Rydere12 Posted July 14, 2022 Author Share Posted July 14, 2022 Prior to instatting Megajolt into fuel injected Fiat I ran the system on a test stand engine that was carb'ed with Weber IDF 40's, all ran well. Noe the Megajolt setup is on a fuel injected engine, same type. Only issue is where do i get a voltage signal that will fire the injectors, remember prior to installing Mrgajolt the signal was coming from the coil that was part of the original distributor/coil ignition system but removed and replaced with the Megajolt/wasted spark ignition system. I have contacted Megajolt, because they are unfarmiliar with the Bosch Fuel Injection yhey did not have a solution. They did suggest acquiring the signal off the Ford EDIS module by attaching a wire to IDM pin location of the EDIS. I'm looking for other suggestions. Link to comment Share on other sites More sharing options...
JohnD Posted July 14, 2022 Share Posted July 14, 2022 (edited) Rydere, Are you confusing Megajolt, an ignition system that uses the Ford EDIS system to provide, er, ignition, with MegaSquirt, an allied fuel injection system? MegaSquirt also uses a trigger wheel to time the injections. John Edited July 14, 2022 by JohnD Link to comment Share on other sites More sharing options...
zetecspit Posted July 14, 2022 Share Posted July 14, 2022 2 hours ago, Rydere12 said: Prior to instatting Megajolt into fuel injected Fiat I ran the system on a test stand engine that was carb'ed with Weber IDF 40's, all ran well. Noe the Megajolt setup is on a fuel injected engine, same type. Only issue is where do i get a voltage signal that will fire the injectors, remember prior to installing Mrgajolt the signal was coming from the coil that was part of the original distributor/coil ignition system but removed and replaced with the Megajolt/wasted spark ignition system. I have contacted Megajolt, because they are unfarmiliar with the Bosch Fuel Injection yhey did not have a solution. They did suggest acquiring the signal off the Ford EDIS module by attaching a wire to IDM pin location of the EDIS. I'm looking for other suggestions. I think, as others have said, you need a trigger wheel/sensor. I don't understand how the edis module can provide the signal. (I did a couple of megajolt installs 12 years ago) Link to comment Share on other sites More sharing options...
JohnD Posted July 15, 2022 Share Posted July 15, 2022 Rydere, Reading back in the post, you said, "Prior to instatting Megajolt into fuel injected Fiat I ran the system on a test stand engine that was carb'ed with Weber IDF 40's, all ran well" I'm confused! Do you mean that the engine HAD been injected, but you tested it with carbs? As said, MegaSquirt needs a crank position sensor, usually provided by a toothed wheel that lacks one tooth. Then absolute timing is done in software. John Link to comment Share on other sites More sharing options...
zetecspit Posted July 15, 2022 Share Posted July 15, 2022 18 hours ago, Rydere12 said: Only issue is where do i get a voltage signal that will fire the injectors, remember prior to installing Mrgajolt the signal was coming from the coil that was part of the original distributor/coil ignition system but removed and replaced with the Megajolt/wasted spark ignition system. Just re-read this. So your injection ecu had a signal from the original distributor/coil, but you want mejaolt to supply the signal now? Is that right? it will depend on when the distributor setup sent the signal I guess.... Link to comment Share on other sites More sharing options...
Nick Jones Posted July 15, 2022 Share Posted July 15, 2022 Yeah, I think we are reading it backwards. He has the Megasquirt working (so presumably has a trigger wheel, EDIS module etc) but needs a way to give the original L-Jet a trigger signal. Presumably it previously got it from the distributor? My thoughts are: - EDIS4 has a 12v tacho out signal (pin 4 iirc, but check!), that might work -All EDIS units also have a “diagnostic” signal (pin 7?) though this also produces a regular pulse when powered up, even when the engine is not running. -L-jet is…… rather old and hard to tweak….. I’d be real tempted to bin it and use Megasquirt which will also do the ignition with the existing EDIS hardware. Edit: Some, if not all, versions of the Megajolt ECU also have a tacho output. (Don’t know which pin) Google suggests that L-jet gets its rpm signal from the coil terminal so it’s possible that it wants a chunkier signal that 12v square wave. If so, you might find this useful https://www.msextra.com/forums/viewtopic.php?t=69602 Link to comment Share on other sites More sharing options...
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