Ozzie831 Posted October 18, 2014 Share Posted October 18, 2014 I was driving pretty quick on the freeway with my megasquirted turbo 280z when all of a sudden my car stopped going forward. I had no idea what was going on so I coasted over into the breakdown lane and looked around to see what had gone wrong. I found that both of Injector bank fuses had blown. Luckily I was with some buddies and they went to the store and got me some more 5 amp fuses. I went to start the car and bam the fuses blew again instantly. So I grabbed my multimeter and we checked how many amps were going through the fuse box and it was about 7.8-8.0 amps which is really random since Ive never had problems with the 5 amp fuses before. So they went and got some 10 amp fuses and now the car wont start. The starter engages and it will start for a split second and then it dies and goes back to cranking continuously until I turned the key to the off position and retry to start it, where it would start and die. I get spark and fuel so Im confused as all hell. Me and my buddies pushed the car to a gas station where I tried to figure out what the problem was but after 2 hours there I decided to give up and walked home. I have no freaking idea what the problem is. My buddy thinks there may be a short somewhere but this all happened at 8pm and it was dark as shit so Im going to go look at it tomorrow to see if I can find anything that may be shorting out. I wanted to post on here to see what others thought, so please any suggestions are appreciated. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted October 18, 2014 Share Posted October 18, 2014 Check to see which fuses blew and what part they control. Check how you wire up the fuses and relay box for M.S.??. You may be checking the relays for those circuits also. Good luck and keep us up to date. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 18, 2014 Share Posted October 18, 2014 Sounds like your injector drivers might have failed open. Probably flooding the engine until the fuse blows. Or you have a short at the power supply to the injectors. Just guessing. You could disconnect the injectors from board to check for a short. The drivers themselves will take more work. Some random links... http://www.diyautotune.com/tech_articles/megasquirt_injector_driver_troubleshooting.htm http://www.msextra.com/forums/viewtopic.php?f=131&t=51994 Quote Link to comment Share on other sites More sharing options...
Ozzie831 Posted October 18, 2014 Author Share Posted October 18, 2014 (edited) So I went digging and looked at every single wire and fixed all the ones that even looked suspicious but the car still does the same shit so I looked in my MS box and lo and behold it smells a bit like battery corrosion. So I drove all over town trying to find someone that even knew what a computer board looked like and finally found someone. They showed me the part that was causing the smell. It was this little black square that has this "F" on it (It is the square on the bottom right of the board in the picture). The guy also showed me this the white stuff that was coming from behind the part and said that was also a sign of it being no bueno. I bought this box from DIY so I have no idea what it is or what it does. So the question is now, buy a new part or just get a whole new MS? Edited October 18, 2014 by Ozzie831 Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 19, 2014 Share Posted October 19, 2014 https://www.fairchildsemi.com/datasheets/TI/TIP42.pdf I took a quick look around the internet but couldn't find an MS board that looks like yours. It could be your injector driver/transistor, based on specs. and what injectors need. BUT, the white stuff might just be heat transfer paste. Not really a sign that it's no good. Did the guy just stick his nose down on the part and proclaim it as bad? It's easily replaced, if it is. Could also just be that the paste shorted the connections. Maybe. You should at least find out what kind of Megasquirt you have. There are several varieties. Quote Link to comment Share on other sites More sharing options...
Ozzie831 Posted October 19, 2014 Author Share Posted October 19, 2014 Thanks for they info. I have an MS1. The sticker on the back of the box says MS122-C Megasquirt-1 ECU w/MS1-Extra 029y4. I just asked for the guys opinion on if the board was toast, I didnt have him do a full diagnostic on it. He thinks the board could still be alright and that the part went bad. He said some parts like that may act like a fuse when it goes bad so it doesnt destroy the rest of the board. Which I think is correct since everything else seems to work fine. I talked to a couple people and they said that the paste shouldnt do that haha, but I have no idea on what it takes to make these boards. I emailed DIY to see what their opinion is, so hopefully I get a response on monday. Quote Link to comment Share on other sites More sharing options...
Ozzie831 Posted October 22, 2014 Author Share Posted October 22, 2014 Quick question. How would you wire the stock resistor packs to the injectors? Im slightly a noob when it comes to wiring so layman's terms would be great haha. I guess this was the step I missed that made my computer explode. I have low impedance injectors and I guess you need resistor packs. Whoops. Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted October 22, 2014 Share Posted October 22, 2014 So I went digging and looked at every single wire and fixed all the ones that even looked suspicious but the car still does the same shit so I looked in my MS box and lo and behold it smells a bit like battery corrosion. So I drove all over town trying to find someone that even knew what a computer board looked like and finally found someone. They showed me the part that was causing the smell. It was this little black square that has this "F" on it (It is the square on the bottom right of the board in the picture). The guy also showed me this the white stuff that was coming from behind the part and said that was also a sign of it being no bueno. I bought this box from DIY so I have no idea what it is or what it does. So the question is now, buy a new part or just get a whole new MS? The white stuff is thermal grease. It's used to conduct heat of the transistor without conducting electricity. It's normal, and required. Quick question. How would you wire the stock resistor packs to the injectors? Im slightly a noob when it comes to wiring so layman's terms would be great haha. I guess this was the step I missed that made my computer explode. I have low impedance injectors and I guess you need resistor packs. Whoops. You just put them in series with the injectors. Battery +12v -> Resistors -> Injectors. Then from injectors to Megasquirt. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 22, 2014 Share Posted October 22, 2014 I guess this was the step I missed that made my computer explode. I have low impedance injectors and I guess you need resistor packs. Whoops. So DIY got back to you and told you that you had the wrong injector setup? Narrow your thought process down from "exploding computer" to "overloaded injector control transistor" if you want to get back on the road. You'll need a soldering iron. Quote Link to comment Share on other sites More sharing options...
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