Xnke Posted February 5, 2014 Share Posted February 5, 2014 I've got this posted up over at MSextra.com as well...JSMCortina keeps pushing this off as ignition timing being stupid high. He hasn't said much after I started posting timing maps from here showing that it's not unusual for L28's to be running 18-24* of ignition timing at idle. Anyway, I am running high impedance "520cc" injectors, at a reduced fuel pressure (they are 520cc at 3.5bar pressure...) which makes them 480cc/min. The opening time supplied with the injectors is 0.85ms at 14V. The engine will idle at 1500RPM and 35kPa at 12.5:1AFR's, injector PW 2.0ms, and ignition timing of 26*. This is the "best" idle I can get...close the throttle plate any further and the idle first becomes unstable, then oscillates wildly, and eventually stalls out on a downswing. It doesn't appear to follow manifold pressure, AFR, or ignition timing, as I can vary all of those things and it will still die out or become very unstable below 1500RPM. I got it to idle at 945RPM (my desired idle speed!) ONE time and if you gave it any throttle it was fine...but when releasing the throttle the engine would immediately die. The engine appears to immediately become unstable and stall out with any injector pulsewidth shorter than 2.0ms...which corresponds to about a 1500RPM idle. I think I have an injector range problem, but since most people on MSextra that have answered are so hung up on ignition timing, I can't get an answer about how to work around this problem. I am currently running alternating, two squirts, and am reading that simultanious, 1 squirt will not result in any change in pulsewidth, according to the manual. However, there are other people on the 'net that appear to have better luck with it that way. It's been raining for four days so far, and shows no sign of stopping, so I will not have any results or any tuning time for at least a week now. Quote Link to comment Share on other sites More sharing options...
Dan_Austin Posted February 5, 2014 Share Posted February 5, 2014 I went through a cycle where my car died every time I lifted the throttle. I was idling at 750 RPM with timing at 22 degrees. I backed the timing down to 17 degrees and no longer stalled on throttle lift. I also have a 'catch' column at 500 RPM where I bump timing up to 19 degrees. I'd be concerned that your dead time, or voltage correction are not quite right. I idle with a .95~1ms pulse with using 475cc low-z injectors., with a 13.5 AFR target I'm on the B&G code which is very limited on setting the voltage correction, so you should have an easier time tuning the correction curve on Extra Quote Link to comment Share on other sites More sharing options...
Xnke Posted February 5, 2014 Author Share Posted February 5, 2014 I've tried everything from 8* to 32*, so i'm not sure it's timing related...hence my asking here. As soon as it stops this torrential flood outside I'm going to try playing with the dead time to see how far off it is. Battery correction Is pretty close; I spent a year chasing it down, unless it changes with injectors or something. Req_fuel is 6.3; so (6.3*0.51)-0.850=2.363, so I don't understand why I'm getting injector pulsewidths of 2.0 and less at that VE... Quote Link to comment Share on other sites More sharing options...
bradyzq Posted February 5, 2014 Share Posted February 5, 2014 (edited) Is it possible that the data really is for opening time, not deadtime (more or less opening time - closing time)? That might explain where your missing 0.35ish ms went, but it won't explain why the car won't run at lower pw. Do you have the small injector pulsewidth table active and zeroed out by any chance? 'Cuz that would impact 2ms and lower pulsewidths. Edited February 5, 2014 by bradyzq Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted February 5, 2014 Share Posted February 5, 2014 Alternator output OK at <1500 RPMS? O2 Sensor calibrated? Timing verified with a light? You can lock the timing to a specified value to hammer down the other idle variables. Quote Link to comment Share on other sites More sharing options...
Xnke Posted February 6, 2014 Author Share Posted February 6, 2014 Injector small pulsewidth table?? WTH is that? This isn't MS3, just MS2Extra. I have no idea what you're talking about there, but if it's in the code I better find out! Alternator output is good, it's an overdriven CS140 amd can supply +22A at idle, and only goes up from there. O2 is calibrated and smack on, timing has been verified with a light and is trimmed in exactly. The timing IS locked; I have tried timing values from 8 to 32* advanced with no change...anything under 2.0ms and the engine gets unstable. It decided to snow tonight, so I didn't go out and play with the car tonight. Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted February 6, 2014 Share Posted February 6, 2014 Interesting. So, can you richen up the 900 RPM VE values to force a idle PW of 2.0ms, or would that be too rich? Do you get any misfires when it starts to die? Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted February 6, 2014 Share Posted February 6, 2014 I've seen an engine with 3 dead cylinders run great at high idle then die at low idle. How is your compression? Or maybe you're loosing spark. What are your ignition settings and what type ignition are you running? Quote Link to comment Share on other sites More sharing options...
Xnke Posted February 6, 2014 Author Share Posted February 6, 2014 spark and compression tests come back fine, no problems there. ignition is edis, wires and coil pack are fine, edis module is good, plugs are ok. I can idle the car at about 950rpm if I really fatten it up, but we're talking off-the-scale rich. Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted February 6, 2014 Share Posted February 6, 2014 (edited) Is this 2ms PW when warmed up? Is TPS accell enrich on? I would turn it off until this is sorted. How far off-scale rich would it take to stall it? How lean can you go? I guess what I'm saying is are your plugs black if you get it to idle nicely at the desired RPM? You have an L28, right? My 3L V6, with lo-z 550cc injectors, set at 44 psi base pressure, idles at ~14.0 AFR with 1.9-2.0 ms of PW, once fully warmed up. Cold it's much higher. I'm leaning toward faulty O2 sensor/controller. Edited February 6, 2014 by BLOZ UP Quote Link to comment Share on other sites More sharing options...
AkRev Posted February 6, 2014 Share Posted February 6, 2014 (edited) Can you post your msq and a datalog. Follow up questions; is the high idle the only symptom? is the engine running rough? I had a similar issue, turned out I spaced the VR sensor wrong and it wasn't reading teeth right. Edited February 6, 2014 by AkRev Quote Link to comment Share on other sites More sharing options...
Snailed Posted February 6, 2014 Share Posted February 6, 2014 (edited) Have you changed the MAP sample angle and MAP window settings? Edited February 6, 2014 by Snailed Quote Link to comment Share on other sites More sharing options...
Xnke Posted February 7, 2014 Author Share Posted February 7, 2014 Set MAP sample angle to 55* and window to 10*. O2 sensor checked against two others, all read the same. This engine and this car idled and drove perfectly fine with MS1Extra, and idled poorly with MS2Extra with a single failing fuel injector. After replacing the set of injectors and rebuilding the exploded intake manifold, setting valve lash and checking ignition timing, i cannot achive the proper idle speed. It's still 20F and now snowing, so there has been no progress today. Quote Link to comment Share on other sites More sharing options...
Xnke Posted March 1, 2014 Author Share Posted March 1, 2014 Worked on the car again. Runs just fine from 1500RPM up. if engine speed drops below 1500RPM, engine will begin oscillations until it swings too low to run and cuts off. Here's a MSQ and Datalog. Rename the file to "2014-02-23_15.08.57.msq", HBZ will not allow files of that type so I just changed the extension. same with the log, it needs to be ".msl"..."2014-02-26_16.45.52.msl" 2014-02-23_15.08.57.zip 2014-02-26_16.45.52.zip Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted March 3, 2014 Share Posted March 3, 2014 I'd start by adjusting the spark table - try around 15 degrees of timing at the RPM you want to make it idle at, and 18 degrees 200 RPM below that. Also, I'm seeing some very lean readings - it looks like the VE table needs some tuning. Quote Link to comment Share on other sites More sharing options...
Xnke Posted March 3, 2014 Author Share Posted March 3, 2014 So why is it when I pull the MS2 daughterboard, unplug the extra 12V lead for the MS2, and plug in my MS1extra processor I can idle the engine wherever I want? This ONLY occurs with MS2. I'm not giving up yet, I'll give it another shot...I think I've got some settings messed up somewhere. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted March 4, 2014 Share Posted March 4, 2014 Do you have a copy of the MS1 MSQ and a data log of how it idles there? Quote Link to comment Share on other sites More sharing options...
Xnke Posted March 5, 2014 Author Share Posted March 5, 2014 Somewhere I've got one. I'll hunt it down later today when I get home from work. Quote Link to comment Share on other sites More sharing options...
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