datman Posted August 26, 2007 Share Posted August 26, 2007 I need some help to cure my RPM spike, I have added a filter to the +12 feed of the megasquirt which stopped most of my spikes. The single wire temp sensor was giving me problems so I have a fixed value resistor in the temp connector to give a 70deg C value until I find the cause. The alternator seems to be causing a lot of noise so I unplugged it, Now most values are stable except for the occasional RPM spike which is causing the engine to stumble on acceleration. I have shielded cables for PIP and Saw, new heavy gauge cable for power supply to the megasquirt and relay board. Can anyone shed some light on the problem? My setup is as follows: l28 F54/P90 Megasquirt II PCB 3 EDIS 123 INJ1 456 INJ2 Alternating Holset H3351CW Low imp injectors (2.1ohm) The car is running great apart from this damn spike, when I disconnected the alternator I unplugged the regulator....would there be any noise still coming from the main power cable with the field unplugged? Here is a log from today. Thanks for looking! sunday26thaug2.zip Quote Link to comment Share on other sites More sharing options...
datman Posted August 27, 2007 Author Share Posted August 27, 2007 Well I fixed the RPM spike by cutting the middle pins on q9 and q12, joining them to a wire and taking that wire to a 12v source before the voltage filter that feeds the megasquirt. This stops the noise from the injectors reaching the MS. This mod is listed on the Megasquirt forum. I still have some noise on the temp signal but only a small amount. Even at 6psi it is amazing how powerful an l28 can be. Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted August 27, 2007 Share Posted August 27, 2007 You go with yo bad self... Quote Link to comment Share on other sites More sharing options...
datman Posted August 27, 2007 Author Share Posted August 27, 2007 Yo Aaron, hows things? you got the Z back on the road yet? Quote Link to comment Share on other sites More sharing options...
datman Posted August 28, 2007 Author Share Posted August 28, 2007 Took the car for a quick drive, running great now http://uk.youtube.com/watch?v=KhmqRSng7q4 ArrrGhhh!!! damn missing codec, no sound. Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted August 29, 2007 Share Posted August 29, 2007 Yea, mine is going great at 14psi right now...need a good clutch and to install a lsd, but already hurting feelings at the drag strip. Is there no sound on your video? Quote Link to comment Share on other sites More sharing options...
datman Posted August 29, 2007 Author Share Posted August 29, 2007 No sound for some reason...play ok on the one I have on my pc but I think there is a Codec problem with the copy I made for youtube.....the sound is the best bit. I will try and sort it this evening. Try the Spec 11lb flywheel and 6 puck sprung clutch....I've got one and its great! Talk to David at Spec, he will sort you a good price. David Norton > S.P.E.C., Inc > 800-828-4379 > fax: 205-491-8593 Quote Link to comment Share on other sites More sharing options...
datman Posted August 29, 2007 Author Share Posted August 29, 2007 I'm a little concerned about a knocking noise....it speeds up with rpm but is not as fast as rpm . You can just about hear it in this video from 1min onwards. Strange thing is you can only hear it insdie the car not in the engine bay http://uk.youtube.com/watch?v=-Tun4UG6a0o Quote Link to comment Share on other sites More sharing options...
datman Posted August 29, 2007 Author Share Posted August 29, 2007 http://uk.youtube.com/watch?v=jaLGlVGA2uo video with sound. Knocking noise was coming from injectors/fuel rail down fuel line to hard fuel line fixed to bulkhead which is why I could only hear from inside the car. Had me worried! Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 30, 2007 Share Posted August 30, 2007 http://uk.youtube.com/watch?v=jaLGlVGA2uo video with sound. Knocking noise was coming from injectors/fuel rail down fuel line to hard fuel line fixed to bulkhead which is why I could only hear from inside the car. Had me worried! So, it was the hardline rattling against the frame? Make sure you get some rubberized clamps if that's the case. BTW, I have had standalones report that much of a rattle (and even less) as knock before. Make sure you go through everything and isolate it or bolt it down, etc. Good luck! I am still assembling my MS2 V3 and gathering parts. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted August 30, 2007 Share Posted August 30, 2007 uhh why doesnt your tach work!? hook it up to the neg terminal on the coil! also your brake light is glowing!! low on fluid or have a ground short on the ebrake handle?! Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted August 30, 2007 Share Posted August 30, 2007 oops Quote Link to comment Share on other sites More sharing options...
datman Posted August 31, 2007 Author Share Posted August 31, 2007 Tach doesn't work as I'm using EDIS, I reda somewhere about using 3 diodes to connect it, will try soon. The brake light is faulty, the wire at the switch keeps touching ground. I have all new brakes/lines/master cylinder. I had my laptop on showing RPM. Quote Link to comment Share on other sites More sharing options...
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