Tony D Posted January 28, 2010 Share Posted January 28, 2010 I second and third the advice on the plugs, DITCH THE EXOTICS AND USE WHAT THE MANUFACTURER RECOMMENDS AND NOT WHAT THE PARTS COUNTER GUY GETS A BOUNS FOR PUSHING! A .69 cent plug works the best in these things, the exotic fine-wire crap seems to foul out every time and have misfire problems. Bosch seems worse than most. Simple plain BPRX-ES seem to do just fine. NGK conventional, Bosch Conventional, Denso Conventional... Hell, Splitfire Autolites work fine, and better than most of the fine-wired crap expecially in turbo service. They mayber fine for a Porsche that was designed around them... but not for the L-Series! Also, turn off all enrichments. ALL enrichments. Let the car warm to operating no matter how many times you have to start it. Once it's warm, with a basic map it will run well enough to do all the tuning you need to do. Enrichments are the LAST step to fine tuning the engine's response. Have them on while you're tuning, and it will only screw you six ways from sunday. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 28, 2010 Share Posted January 28, 2010 I only had a quick moment to look, but I see that the cranking rpm is zero - set it to 300 or so. At zero it means that as soon as the engine begins to crank MS will immediately go into run mode. That doesn't explain your lack of spark, but it isn't helping. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 Okay, I'll change plugs and change my cranking RPM to 300. As far as enrichments, how do I turn them off? Is it as simple ad setting all the values to zero at all thevarious temperatures? Also, did anyone ever thunk about why my spark output light is on constantly? Thanks again guys! Quote Link to comment Share on other sites More sharing options...
mobythevan Posted January 28, 2010 Share Posted January 28, 2010 Looking at you msq, maybe it is not loading correctly for me, but just to verify: Under "crank/warmup", then under "more cranking stuff", what is your "cranking RPM" and "TPS value for flood clear"? Like Zmanco pointed out, the cranking rpm is loading as zero for us. I also see the flood clear as zero. If that is true I think when you are cranking the car megasquirt thinks it is in flood clear all the time(the TPS at rest will read some raw value above zero from my experience, usually less than 30). That would explain why it won't fire any more even if it gets spark. It is only getting the priming pulses I guess and nothing more. This value should be something like 200. Let us know if your megatune show a zero for both of these. If it does, set cranking rpm to 300 and flood clear to 200. That won't fix any spark issues like Zmanco said, but these need to be fixed or it won't fire up correctly and transistion into ASE and WUE smoothly. Maybe the msq is not loading correctly for us. Otherwise settings look in the ballpark and I don't see anything else obviously wrong. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 Okay cool! Yeah, they were set to zero, I just fixed it. So as far as no spark...what should I try? The megasquirt is getting an RPM reading while I crank. I was getting periodic spark as shown in the video, but now I'm getting nothing. Could it be my coil? It's an MSD blaster 2 which has never given us issues, as far as I know. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 28, 2010 Share Posted January 28, 2010 After making the changes Moby and I recommended, have you tried to start the car? If not, try it again before you change things further. It's a good practice to try one thing at a time. Change too many at once and it's easy to get into never-never land. Assuming you try it and it doesn't start, my next question is how are you driving the coil? Is MS driving it directly or are you using something else such as MSD? You said Megatune is showing an RPM reading when you're cranking, so it sounds like the dizzy to MS interface is ok. It's rare that you'll damage the coil - more likely to damage the MS driver. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 I believe MS is driving it correctly. We used this wiring diagram: I have not tried to test the spark, but I will when I get home this afternoon. Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted January 28, 2010 Share Posted January 28, 2010 Did you jumper the board per the DIYAT site? http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_280zx_turbo.htm You have the exact same setup that I have. If you need some maps or setting info I can get some screen shots for you. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 Yes it is jumpered. Like I said, it is a running setup other than this spark issue which had only recently occurred. Should I start checking wiring for loose wires and such? Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted January 28, 2010 Share Posted January 28, 2010 Did it start happening when you chagned the tune to a different MSQ or was it just random? My Relay board broke off a solder on one of the relays and wouldn't let my car start, just like yours. You might want to take is apart, make sure everything is visibly okay, then bench test it with the ECU to make sure everything is working. Quote Link to comment Share on other sites More sharing options...
blackhat Posted January 28, 2010 Share Posted January 28, 2010 Change too many at once and it's easy to get into never-never land. He's REALLY not kidding... Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 I had swapped my head gasket and didn't really mess with it since. Then I had issues and shot that video, then I tested my coil ohms and pit the leads back on and tested my plugs again and voilà , no spark. If megasquirt is getting an rpm signal, does that mean the dizzy is triggering megasquirt to fire? Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted January 28, 2010 Share Posted January 28, 2010 I had swapped my head gasket and didn't really mess with it since. Then I had issues and shot that video, then I tested my coil ohms and pit the leads back on and tested my plugs again and voilà , no spark. If megasquirt is getting an rpm signal, does that mean the dizzy is triggering megasquirt to fire? Not necessarily. The tach signal is an input, spark is an output. Check your relay board... Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 Okay bit I'm just trying to confirm I dont have a bad distributor, just to eliminate a variable. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 I can look it over, but I'm not sure how I would bench test it. Any suggestions? Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted January 28, 2010 Share Posted January 28, 2010 A multimeter, and a battery for the switched and 12V power. I set up a little bench tester when mine was acting up. I found out my FP wasn't getting power [so the fuel pump wouldn't turn on and the Coil + didn't have any power]. When I saw that it wasn't getting power, I found the solder had come off the board at the FP relay, soldered it back up and it was good to go. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 Now that I think about it, the fuel pump is wired to the old switched 12v source AND the relay board because we were having this nasty backfire issue where the fuel pump would lose power abouve about 2300 rpm and everytime the car would pause and then BOOM! A giant lean backfire would occur. Could this be an issue? I'm afraid if it is, then I'll turn around and have problems with the fuel pump again....hmmmm Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted January 28, 2010 Share Posted January 28, 2010 What fuel pump are you running? Quote Link to comment Share on other sites More sharing options...
jacob80 Posted January 28, 2010 Author Share Posted January 28, 2010 Walbro 255 pump Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 28, 2010 Share Posted January 28, 2010 Now that I think about it, the fuel pump is wired to the old switched 12v source AND the relay board because we were having this nasty backfire issue where the fuel pump would lose power abouve about 2300 rpm and everytime the car would pause and then BOOM! A giant lean backfire would occur. Could this be an issue? I'm afraid if it is, thenI'll turn around and have problems with the fuel pump again....hmmmm Generally it's not a good idea to power something via 2 separate paths. And it complicates troubleshooting as well. But why do you think how you are powering the fuel pump is the cause of your lack of spark? I don't follow your logic. Quote Link to comment Share on other sites More sharing options...
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