Metro Posted January 20, 2006 Share Posted January 20, 2006 Man, I'm really starting to wish I had gone with a carbed v8.. I don't know what it is with this motor, but it'll run great, then horrible, then great. There's always something going wrong I've had the car running with MSnS-E for about 3 months now. I've had various problems with it, but I was able to diagnose and fix it without any problems. A few days it was hard to start, just sputter and die. Then it wouldn't start at all and after a few checks, found it was spark related. MS was also slow to turn on after the key was turned, so I reflashed MS and reloaded my settings - solved that problem. I was hoping the spark problem was related to that, but no such luck so I continued on. My setup: Relatively stock 81 L28et MSnS-E - v3 pcb with all the goodies '76 VR Distributor MSD Blaster coil New GM HEI module New plug wires New NGK plugs Checked the coil and HEI module by running a wire directly from the coil to the battery. Touched the G pin on the HEI module to power and watched the coil spark. I also made sure the coil was getting 12 volts when cranking. Next thing to check would be the signal from MS, so I hooked up a LED to the FIDLE output at the HEI module. I have it wired up exactly like moby, getting power from the TPS reference. The LED turned on when MS turned on (correct?) and it flickered like it should when I cranked the motor. DMM read 4.83 volts and dropped slightly when cranking. All the sensors readings in MS look fine, so I'm really stumped. Everything I can think to check with the ignition checks out fine. Honestly, I don't expect anyone to find an answer for this. It has to be something crazy or something incredibly stupid I've missed. Quote Link to comment Share on other sites More sharing options...
Metro Posted January 21, 2006 Author Share Posted January 21, 2006 Ok, after playing with it some more it would seem that there is something wrong with the signal. It looks like HEI module won't spark if there's a constant voltage applied. So something is wrong with the FIDLE circuit - it grounds out the 5volt signal which is the opposite of what the HEI module is expecting. Problem is, I have no idea where to look to fix this, I think I'll hit the MS forums now. Quote Link to comment Share on other sites More sharing options...
Metro Posted January 22, 2006 Author Share Posted January 22, 2006 Well, I disconnected the resistor that connected the 5volt to the FIDLE output and voila, sparks again. So now I need to find where something is touching to give it power or disable all the mods for the VB921 ignitor I'm not using. Quote Link to comment Share on other sites More sharing options...
ngrimm Posted January 24, 2006 Share Posted January 24, 2006 Thanks for posting the solutions so far. Not everyone does that and it helps the rest of us when we have problems. I'm here in Medford trying to finish the install on my 300zxt. Would like to see your car some time. Norm Quote Link to comment Share on other sites More sharing options...
Metro Posted January 25, 2006 Author Share Posted January 25, 2006 Well I'll post a few more updates from what I've learned. It's normal (or at least it works fine) when the FIDLE has power when the key is on run. So if you had a LED hooked up, it would light up when the ignition is on run. Basically my problem was, there were two sources supplying power to the FIDLE wire. Something on the MS board is giving it ~1.2 volts and then there was the 5 volts I supplied it. I still don't understand why that wouldn't work this way, I guess the HEI module just didn't like the signal. I'm here in Medford trying to finish the install on my 300zxt. Would like to see your car some time. Norm Yeah I saw some post from you about the holset turbos a while back. I've never met any of the hybridz guys around here, but there's like 4 or 5 on this board. As for my car, it's going to be back in paint jail soon to fix the damage from when I got rear ended last month. I'll definitely be hitting the drag strip this spring and hopefully I'll have MS tuned by then. Quote Link to comment Share on other sites More sharing options...
ngrimm Posted January 25, 2006 Share Posted January 25, 2006 Never heard about your accident, that's too bad. I had heard one reason the turbo L28 is a little sluggish off boost is that the stock ecu retards the timing to help spoolup. Have you noticed any driveability improvements with the MS over stock? Also any plans for raising the boost? Norm Quote Link to comment Share on other sites More sharing options...
Metro Posted January 25, 2006 Author Share Posted January 25, 2006 Hmm, can't really comment on drivability, I had mucho problems with the stock efi (I think I fried the ignition transistor) and went to MS after only two months. It does seem to idle smoother and throttle response seems better. I'll definitely be raising it to 10psi, I have the grainger installed, but I haven't adjusted it. I don't have an intercooler yet, so I probably can't go much more than 10. Quote Link to comment Share on other sites More sharing options...
ngrimm Posted January 25, 2006 Share Posted January 25, 2006 Don't blame you for being cautious with the boost. I have a LM1 if you should want to check a/f when you raise the boost. Whichever Z I keep I think I'll go with water/alky since I've had really good results on my Mustang. I think it's pretty good insurance and in some ways easier to install than an IC in some cars. Just let me know if you want to hook up the wideband. Plus I may need to ask you some questions when I get stumped on the MS. Norm Quote Link to comment Share on other sites More sharing options...
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