bryan01 Posted May 17, 2007 Share Posted May 17, 2007 i lost my spark! it was running a month ago before i pulled off the intake plenum to replace the injectors and add a megasquirt. i finally got the MS working and low and behold i have no spark. here's a copy of an email i sent to a friend just so i dont have to write it all again ... any ideas/tests i can check out would be great ... tonight i'm going to go back to the garage and put my meter to the coils and see if they're getting power, but if they're not i'm not sure what to do b/c i have everything wired still, so i dont know So there’s no f’n spark. Nothing. Not even a static shock. First of all the battery got down to 10v while I was trying to start it. then I pulled the plug wires and pulled one of the plugs. I attached that plug to the wire and touched the side of the plug to the valve cover (attempting to ground it) and cranked it. no spark. I looked for a better ground w/in reach, tried 2 more spots just to be sure, and nothing. Then I tried it with the ole screwdriver in the plug socket technique. I had kim crank it and I held the screw driver near ground, and it didn’t arc. !?!?!? I didn’t mess w/ the spark at all. nothing. All I did was wire in the megasquirt. I connected everything just to make sure it didn’t need a ground somewhere that it wasn’t getting. I had the old o2 sensor wired into it’s stock connection and the old injectors (even thou neither were in use) just to try to simulate the same situation before the squirt. Didn’t work. I pulled all the fuses for the squirt and tried again, didn’t work. I pulled the battery out of my jeep b/c by this point I’m sure the battery was more like a 9v battery than anything. I brought the jeep battery into the garage and jumped it to my z battery and it was back up to 11.5v … no spark … ever get so mad at something, not someone, that you want to explode? That was me last night … I was so pissed at an inanimate object it was comical. Anyways, ideas? It ran before I pulled the plenum and added the fuel. the only wires the megasquirt is tapped into is the tps sender wire, one of the crank angle sensors, a power wire (for the fuel pump, after it’s relay – and the pump is working fine), the new o2 sensor. It’s also connected to map, clt, and ait, but those are it’s own sensors. I’m thinking of just removing it all and starting over. I could knock the broken insulators off the stock injectors and install them. I could put everything back to the way it was (minus the plenum) and see if it will start. All my relays are still clicking by the way, so that’s not it. Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted May 17, 2007 Share Posted May 17, 2007 Might have messed something up with the CAS. That sensor is reading where the crank location is and sending that information to the computer as an input to fire spark, I would try going there first since that is one of the things you have messed with. Quote Link to comment Share on other sites More sharing options...
bryan01 Posted May 17, 2007 Author Share Posted May 17, 2007 i agree. i'm going to unplug the MS from that wire and see if that helps. even thou i pulled the fuses it could be interfering with it some how ... and like you said, it's one of the only real things that i messed with. Quote Link to comment Share on other sites More sharing options...
Careless Posted May 18, 2007 Share Posted May 18, 2007 ever get so mad at something, not someone, that you want to explode? That was me last night … I was so pissed at an inanimate object it was comical. went through that this weekend. tried to start my car to show a friend how loud a car with an open header is cause she was like "i dunno how loud my car would be if i did that" wouldnt ♥♥♥♥♥♥♥ start. tried and tried... revisited my wiring, then i found that by removing some of the wiring under the seat, i forgot to plug the fuel pump harness back in. stupid me. thing started within 2 minutes of cranking and pumping, and boy did it sure run but yah, have you made sure that the ignition circuit on the ms board was soldered properly? did u test with the stim? Quote Link to comment Share on other sites More sharing options...
bryan01 Posted May 18, 2007 Author Share Posted May 18, 2007 i'm only using the MS for fuel. the ign system is the stock rb system. and yeah, i used a stim to make sure it worked, then connected it to all the sensors and got good/correct readings from them all ... i even get pulse widths and spray from the injectors, just no f'n spark to spark it ... Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted May 18, 2007 Share Posted May 18, 2007 Did you get the harness grounds reconnected when you put everything back together? I had a misfire due to a bad harness ground at the front of the motor near the water outlet on the intake manifold. There is also a small ground on the back of the intake manifold as well. Evan Quote Link to comment Share on other sites More sharing options...
bryan01 Posted May 18, 2007 Author Share Posted May 18, 2007 now there's something i can try too. currectly the grounds in the front are connected to the same bolt on the new intake plenum. but the new intake plenum is polished aluminum with a coating on it ... maybe it's just not getting a good ground at that point anymore. and what ground are you talking about at the rear of the intake plenum? are you talking about the spark part of the harness that is grounded at the back of the valve cover area?) the only grounds from the engine bay area that arent megasquirt related that i have connected are from the block to the frame and there's a ground from the end of the wiring harness (less than 10 inches from the final big battery power connection) that i have connected to ground as well. and then those 2 that are connected to the intake plenum in the front ... i'm going to go back over the harness when i get home from work and make sure it's all connected, and unhook the squirt completely and see if i cna get her to spark w/o connecting the old fuel setup. Quote Link to comment Share on other sites More sharing options...
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