punk_a_saurus Posted April 30, 2014 Share Posted April 30, 2014 Hey guys I'm trying to fix my megasquirt but can't figure out what the problem is, it's running a 1jzgte in a fc rx7, when I bought the car there was no issues ran fine etc, first cold start I got down the road and the ecu cut out then came on again a couple times, (I can see it cut out in the glovebox, when the 3 firing lights on the side die). This has gradually gotten worse to the point where I can start the car sometimes but when I try and move it it cuts out again.. Any help would be appreciated! And yes I've checked all the obvious things like battery terminals etc Cheers! Quote Link to comment Share on other sites More sharing options...
peteretep Posted April 30, 2014 Share Posted April 30, 2014 it sounds like a loose connection somewhere, try following all the cables throughout their whole length and/or put a multimeter on each end and move the cables around to see if you lose connection I would like to see pics of the car/engine bay Quote Link to comment Share on other sites More sharing options...
downtrail Posted April 30, 2014 Share Posted April 30, 2014 Check connections to where the timing signal is taken from. and its not flooding is it? Quote Link to comment Share on other sites More sharing options...
punk_a_saurus Posted April 30, 2014 Author Share Posted April 30, 2014 Could possibly be flooding? When you go WOT it feels a little hesitant. Will upload pics after work Quote Link to comment Share on other sites More sharing options...
downtrail Posted April 30, 2014 Share Posted April 30, 2014 ok check the tps is reading a full 0-100% sweep as well. do you have a laptop to connect in with? Quote Link to comment Share on other sites More sharing options...
punk_a_saurus Posted April 30, 2014 Author Share Posted April 30, 2014 EDIT: yes it is flooding, when it cuts out while driving and comes on again it backfires Quote Link to comment Share on other sites More sharing options...
punk_a_saurus Posted April 30, 2014 Author Share Posted April 30, 2014 Have laptop just need tofind a cable. Never dealt with these ecus/software before though Quote Link to comment Share on other sites More sharing options...
Testament Posted April 30, 2014 Share Posted April 30, 2014 check all the grounds. check the crank position sensor distance to the trigger wheel and wiring. it could be missing sync then the thing thinks its starting again so then it adds start enrichment fuel. you really need a laptop to check though. welcome to the confusing muddle that is sorting out megasquirt issues. grounds and clean spike free power supplies are the gospel of this necrocomnicon. Quote Link to comment Share on other sites More sharing options...
Testament Posted April 30, 2014 Share Posted April 30, 2014 also the DSE usb to serial adaptor cables seem to work ok. have not had good luck with any others despite often looking almost identical. Quote Link to comment Share on other sites More sharing options...
Burntrubber Posted May 1, 2014 Share Posted May 1, 2014 You defiantly need to sort laptop out and data log it you'll be able to see everything that's happening when it cuts out. In saying that you'll need to learn how to read the logs also which isn't hard but will take bit of time. Everything else has been covered if it has even a little bit of dodgey wiring it'll play up. For me battery in the boot and old worn starter made for couple of years of crap starting until I recoed the starter cause it died. Once recoed it pulled less current and the megasquirt didn't get all pissed off. Quote Link to comment Share on other sites More sharing options...
sentra Posted May 1, 2014 Share Posted May 1, 2014 EDIT: yes it is flooding, when it cuts out while driving and comes on again it backfires not wanting to explain how to lick an egg, however incase you were unawares, ignition failure causes the same issue - puts unburned mixture in the exhaust ready to backfire when the ignition starts going again Quote Link to comment Share on other sites More sharing options...
downtrail Posted May 1, 2014 Share Posted May 1, 2014 this^ yep if it looses sync it'll probably pump in the after start enrichement again so extra fuel = flooded. you need to run a log sent it to me if you like. Quote Link to comment Share on other sites More sharing options...
mark105 Posted May 1, 2014 Share Posted May 1, 2014 Tomstament is on to it, follow his advise first, bad earths will cause you many head aches. It sounds like it is doing a reset and a laptop will confirm this for you. If its resetting my money is on bad earths or bad power source. Get them sused first cause like any ECU it wont run properly if they arent. Quote Link to comment Share on other sites More sharing options...
em_knaps Posted May 2, 2014 Share Posted May 2, 2014 A sure fire fix of any megasquirt is to remove the ECU from the car and place it in a good strong vice, do the vice up nice and tight till you hear cracking and breaking noises coming from the ECU (do no be concerned with these noises as they are essential to the process) once the ECU has been compressed to a ~10mm thickness the process is complete. if this helpfull tip is not to your liking then checking spark plugs and ignition system is a good idea as a missfire due to a dirty plug or a weak spark can cause the ECU to loose sync and cut all spark/inj events causing nice fresh air to enter the exhaust system via the engine. it mixes nicely with unburnt fuel and when the engine turns back on it all gets ignited give off a loverly loud bang and sometimes nice flames too.... Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted May 2, 2014 Share Posted May 2, 2014 That's bullshit. There's not much wrong with the ms units. He'd be better off giving it to me Quote Link to comment Share on other sites More sharing options...
Burntrubber Posted May 2, 2014 Share Posted May 2, 2014 Agree meagasquirt ecus are awesome it's the DIY design of them that gives them a bad name because 90% of the people who chose them because of the cost and the fact they can do it themselfs actually can't. They still need to be set up to a professional standard not backyard styles lol. Even a factory or top brand aftermarket ecu will have problems if the wirings dodgey. Quote Link to comment Share on other sites More sharing options...
em_knaps Posted May 2, 2014 Share Posted May 2, 2014 yea, I was being a bit mean, I'm usually a megasquirt defender but by a product of their firmware and hardware design they are vulnerable to noise issues. something oem and higher end aftermarket ecu's do not suffer from. though in value for money stakes they can not be beaten. I've learnt sooo much over the past decade of DIYing EFI with megasquirts as my ecu of choice. A nice install is all they need to be reliable. at one stage I had 3 cars all with megasquirts and all reliably daily driven for a period of time. what punk is describing sound like a lose connection somewhere. 1 Quote Link to comment Share on other sites More sharing options...
punk_a_saurus Posted May 7, 2014 Author Share Posted May 7, 2014 So I fixed it.. Turns out it was a loose ground wire. Seeming to run all good now have been driving it to work for the last few days. Here are some pics (shit ones) Quote Link to comment Share on other sites More sharing options...
punk_a_saurus Posted May 7, 2014 Author Share Posted May 7, 2014 although I say its running fine, I still think its not running to its full potential. it feels really hesitant when you go foot flat, and a slight miss. im looking into doing a single turbo conversion in the next couple weeks, and ill be looking for someone on here hopefully to dyno it/road tune it Quote Link to comment Share on other sites More sharing options...
downtrail Posted May 7, 2014 Share Posted May 7, 2014 Dependent on where you are I can road tune for you. Quote Link to comment Share on other sites More sharing options...
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