icarus Posted March 18, 2009 Share Posted March 18, 2009 haha, yeeeeah. so my s130 (L28et MS1v3) broke down on me a while back after several months of daily driving on a new MS setup. at first i thought that it was a spark related problem caused by a really shoddy temporary fix that i used in the harness that went to the CAS in the zxt dizzy... so, assuming that that had been the problem i proceeded to just tear out the whole dizzy/spark setup that was in there as i had been meaning to set up my EDIS for some time anyway... but NOW i popped open my MS ECU to put the MS-II board in there (to run my new EDIS setup) and i discover that one of the transistors in my PWM circuit has gone and BLOWN UP on me. it was part #Q9 on the illustration below: http://www.megamanual.com/ms2/v3components.gif the little "chip" is like fractured and almost half of it was floating around loose inside the case, the floating piece was just the plastic housing. all of the little metal 'guts' of the chip still in place but seem like they may be sorta melted/damaged, although i cant honestly say i know what they are supposed to look like... my questions: 1: what could have caused this to happen? 2: would this have caused the car to die? a couple facts that may help solve the puzzle; i drove the car for several months before this happened, without changing anything. when the car died it was running normal/great then just out of nowhere sputtered and puttered out (on the freakin onramp/overpass to the freeway:icon56:). after this, it would not start again, at all. i believe my foot was in it when it did so, but it wasn't wrapped out all the way or anything. while cranking it in my garage later i noticed that the front three injectors were leaking and pouring out a little stream of vapor and/or smoke, but i dont know if this was pre-existing or not. the front three and the rear three injectors run off the same inj harness primaries (i.e. 1-3 off inj batch 1, 4-6 off inj batch 2). any input is appreciated. my only real concern is that i perhaps have something setup wrong that will cause it to happen again after i replace the part... or maybe its just a fluke..? Quote Link to comment Share on other sites More sharing options...
icarus Posted March 18, 2009 Author Share Posted March 18, 2009 i found another ... thing... of interest. was inspecting the board and noticed this; a piece of circuit path in the board appears to have overheated as well, it was darkened, and when i touched it the surface material flaked off a little so i could see straight copper path... and this strip is of course directly on path to the burned PWM transistor Q9 (is it on path TO or is it on path FROM?) im really hoping that this was just a fluke bad chip that caused a little bit of superficial damage to the board and once Q9 is replaced itll be all good... anyway, again, any input will be much appreciated. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted March 19, 2009 Share Posted March 19, 2009 That looks like a flyback failure or a 12 volt spike. What sort of injectors are you running? Quote Link to comment Share on other sites More sharing options...
icarus Posted March 19, 2009 Author Share Posted March 19, 2009 i am running the stock L28et injectors on this rig... this was the first MS harness that i built and i just realized that i didnt put any fuses in line with the power leads to the injectors (as is called for on the MS diagrams ive seen) would this have protected the board? but im sure that couldnt have CAUSED the problem because popping fuses isnt supposed to happen either... what would cause a 12v spike? once i replace the Q9 transistor should everything be fully functional again? Quote Link to comment Share on other sites More sharing options...
z-ya Posted March 19, 2009 Share Posted March 19, 2009 Do you have a resistor in series with +12v and each injector? If not, what are your PWM settings? Pete Quote Link to comment Share on other sites More sharing options...
icarus Posted March 22, 2009 Author Share Posted March 22, 2009 no, i dont have any resistors in any of the +12v running to the injectors. heres a quick sketch (or 'paint') of how i have them set up... no resistors, and no fuses in line with the injectors as it sits now. the +12v to the injectors comes from the MS Main Relay... Quote Link to comment Share on other sites More sharing options...
z-ya Posted March 22, 2009 Share Posted March 22, 2009 What are your PWM settings? You need to enable PWM to drive low impedance injectors without resistors. What injectors are you using? Quote Link to comment Share on other sites More sharing options...
icarus Posted March 23, 2009 Author Share Posted March 23, 2009 i am running the stock L28turbo injectors right now. i have been running these all along, and i was daily driving the car for several months using whatever settings that i currently have... so i would imagine that they must be correct or else it wouldnt have been working fine for so long..? i am going to see if i can find exactly what they are though, gonna go look through them when i can get to my MSlaptop later. where are these located exactly? i dont recall having to set up any PWM stuff, other than just setting it to use 'peak and hold' (i.e. low imp) injectors... 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.