naviathan Posted July 22, 2007 Share Posted July 22, 2007 I'm so fed up at the moment it's not even funny. The car will not idle on it's own at all. I've been playing with timing settings all day and still get get it to start without giving it some throttle and feather it to keep it going. I'm at a loss. I don't know what to do. Let me elaborate a bit. This morning I set it to TDC made sure my rotor was pointing towards the number one plug and the crank pulley was at 0* as it was suppose, pulled a Timing Advance table off the forums recalculated my required fuel and started cranking. I stopped only to charge the battery when it got low and change the Trigger Offset value. I have been everywhere from -10 to 92 and still no start anywhere. What am I doing wrong here??? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 22, 2007 Share Posted July 22, 2007 Do you have a timing light? before you even get it fired, you should make the timing light on the crank pulley match the MS-II readout during cranking. If you don't do that first, you are juggling too many variables at once and it will be like planning on hitting the lotto. 1)Confirm Timing. with a light and the trigger offset. (while cranking) disconnect the injectors or fuel pump. 2) Set the ignition MAP to 15BTDC all the way across (tweak later) 3) Set your injection to two squirts alternating or simultaneous 4) Enter an estimated VE for the idle areas of the map... 30 to 50 range my guess. 5) Turn off ALL or your enrichments AE,ASE, Warmup wizard....... 6) Go to the Required Fuel window and crank the key while going up and down with the Required Fuel number until it idles. Quote Link to comment Share on other sites More sharing options...
z-ya Posted July 22, 2007 Share Posted July 22, 2007 Did you adjust the idle screw on the throttle body? Adjust it so that it idles. Then check your timing with a light. it should idle fine at 25deg. The timing in the table for the active bin should match the light. Use the trim in the spark settings to compensate for any error. Once you get the timing and fuel right at idle, you may need to readjust the idle screw. Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 Adjust the idle screw? I have a GM IAC stepper motor. The only thing that I can adjust on the throttle body is the TPS and the throttle plate stop screw. Is that what you're talking about? The stop screw? Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 Ok, so I need someone to crank the car while I sit with a timing light and try to verify 10 degrees BTDC while cranking? Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 Since I know how much everyone loves eye candy, here's some window shots for you to peruse... Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 23, 2007 Share Posted July 23, 2007 The maps look fine to start with. During cranking, watch the timing light AND the Trigger Offset window at the same time. Adjust the trigger offset number until they are as close as you can tell. My trigger offset ended up being (negative) -66. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 23, 2007 Share Posted July 23, 2007 OK wheres the video of it running? I know it's coming soon! Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 I will gladly post a video of it running as soon as it does run...lol Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 The maps look fine to start with. During cranking, watch the timing light AND the Trigger Offset window at the same time. Adjust the trigger offset number until they are as close as you can tell. My trigger offset ended up being (negative) -66. You mean the Trigger Wizard under tools right? The one that says match timing light to the above value? My timing light is static and all I can go by is the timing plate by the crank pulley. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 23, 2007 Share Posted July 23, 2007 Yeah go by the timing plate ont eh front of the engine. Eyeball it. Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 Well, lovely thing happened while I was eyeballing the timing. MY VB921 had a melt down. My spark started getting inconsistent and then POOF no more. Quote Link to comment Share on other sites More sharing options...
z-ya Posted July 23, 2007 Share Posted July 23, 2007 Adjust the idle screw? I have a GM IAC stepper motor. The only thing that I can adjust on the throttle body is the TPS and the throttle plate stop screw. Is that what you're talking about? The stop screw? Yes, idle stop, idle screw, whatever you want to call it. It is how you adjust how much air goes into the engine at idle. Are you sure it is the VB921? You have the spark inverted in your settings (as it should be). The VB921 should be driving the negative terminal of the coil. Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 Does that screw really need to be adjusted? I thought the IAC would take care of the idle air flow. Oh yes the VB921 is blown, bad. It melted the nylon screw to nothing. I plugged it into the stim and I'm getting everything except ignition. Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 On further investigation I think it was either the jump box I had connected to the battery to keep everything going or the pull up resistor that blew the driver. One of the legs on the pull up appears to have broken contact. I think it was intermittently making contact and might be what did it. This time I'll do my pull up on the board and not in the wiring like I had it. Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 Tested the board. R43 is blown closed. I wonder if that's what caused the VB921 to blow, or if that was a result of it? Quote Link to comment Share on other sites More sharing options...
mobythevan Posted July 23, 2007 Share Posted July 23, 2007 Does that screw really need to be adjusted? I thought the IAC would take care of the idle air flow. Any given engine will require an airflow to idle, you can start by opening your idle valve all the way. If that is not enough air, then you need to open the throttle plate to allow more air. As simple as that. Every engine I start with megasquirt I do two basic things. I have someone else crank the engine from inside the car while I check the cranking timing with a light (without checking timing how will it ever start, just by luck?), and then I operate the throttle blade by hand while they crank it over. That way I can adjust the airflow to get it to start, then adjust the idle screw to hold the plate open. This method works very well, all engines start right away with the required fuel calculated from megasquirt. Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 Thanks Moby, I guess those are the steps I'll need to take once I get my MS back up and running. Have you ever heard of a VB921 actually blowing? What reason could it have done that? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 23, 2007 Share Posted July 23, 2007 The wrong settings in the ignition setup can blow it up. Ask Big-Phil. He even has a video of him replacing it. Quote Link to comment Share on other sites More sharing options...
naviathan Posted July 23, 2007 Author Share Posted July 23, 2007 With the tables listed above I think when it blew when I had my Trigger Advance at 4 or 5 trying to find my mark with the timing light and bumping it up from there. It was somewhere between 4 and 20 that it fried. Quote Link to comment Share on other sites More sharing options...
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