First drive after 13 years!

vraned

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I just took my coupe for its first spin around the block. Only a half mile, but I can hardly believe it. I've spent the last 3-weeks getting it sorted enough to drive to the glass shop, which was supposed to be today. I had to cancel because of rain this morning, but it was dry enough to give it a quick spin this afternoon. While megasquirt obviously is not dialed in yet, the car ran very smoothly, accelerating surprisingly well with the initial tables. This is going to be a blast. I'll post some pics on vranedom. Really, I cannot believe this day has finally arrived!
 

Ed G

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Congrats!!!! Post those pix. Make sure you include one of your smiling mug! Great work also documenting the process so far!

Happy New Year to all!
 

Nicad

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Great way to end the year. Looking forward to posts on perfecting your Megasquirt in 2012.
 

vraned

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Noodle.

So I drove the car to the glass shop on New Year's eve day. Round trip was about 15-miles. I used masking tape to hold the windows in place on the way to the shop, and could hear the headliner flexing just pulling out of the driveway. Serious body flex without the windows in place. Upon reflection, this justifies the flatbed argument I had with a tow truck operator a while back.

The glass shop came highly recommended from a local coupe specialist. I was advised that e9 windshield installation was a three-man operation and to be prepared to witness some professional grade man-handling. I was not disappointed. The rear windshield installation looked like a gang initiation (as performed by guys in their late 40's-early 50's). Following the usual string pulling maneuver, they literally beat the window into the best fitting position, and then violently rocked the car to relieve the stress. Surprisingly, the front was more of the same, but to a much lesser degree. I had needlessly spent hours sweating the tight clearance between the recovered dash and the lower mounting lip. The seals look even within the frames both inside and out. Nice.

Windows secure, the drive home warranted some fuel injection exploration. Idle definitely needs more work. The startup and warmup enrichments seem fine as idle is high, but rock stable, during these periods. Once thoroughly warmed up, however, the engine has a slight hunt (+/- 30-rpm) about 900-rpm. Enrichment needed. Megalogview indicates smoothest idle at about 13.7 AFR. It looks like it is hovering between 14-15 when warmed up. Off idle, the engine feels smooth. Acceleration brought a very deep feeling of satisfaction and a ridiculous smile to my face. A lot quicker than my tired Bavaria. Nice exhaust note dominated by huge intake sound. Before leaving the house, I had enabled megasquirt automatic mixture control (AMC), with 300-second flash update. Upon getting home, I was surprised that my VE table had not been adjusted at all. I am not that good. Once my laptop battery arrives, I will try this again through Autotune. Based upon my interpretation of the group, it looks like I'm running a pretty standard engine configuration: M30B35; ported '89 big valve head; Schrick 284 symmetric; Stahl headers; E32 port matched manifold; stock 635 injectors. The injectors will probably have to change to get the most of out of the engine. I'll post the tables once I am satisfied with the basic set up as a starting point for other folks interested in megasquirt.
 

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David, great that you have it driving now - what patience you have. What version of MS are you using? I too am having problems with an idle that is not as smooth as I think it should be. I have not been able to get it below 850 rpm, usually it idles around 900 ±30/40. Sometimes it runs with variation I have found that the 3 wire PMW idle valve does allow a bit of air through when completely closed. I have the idle screw and idle stop all the way closed. The speed does not bother me as much as the oscillations.

I am running the e32 engine stock with the old style intake and 3.0 exhaust (to be changed later when I feel like forking out for Coupeking's SS system). Running beta 1.04 MS3X. How have you tuned your spark map? I think I have my tables dialed in fairly well. I just do not know how much power I am leaving on the table because of spark advance. Starting is ok, warm-up is good and acceleration is smooth. There is a ton of reading available online about the MS system.

have fun,
 

vraned

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Sven, I'm running an MS2 V3.0 board with V2.89 firmware, IIRC. I went for the MS2 because I wanted to solder it up myself. I am also inclined to suspect the idle valve for other reasons, like me taking it apart, but I would like to resolve the following issues. First, I noticed that the rubber tube (new from pellican) between the valve and manifold collapses at idle. If it is collapsing to the point of choking the engine this could set up an oscillation. The throttle plate is completely closed and I am running 43% pwm @160-Degrees F. Second, my simple 3-wire circuit might be unstable as I designed it myself. It seems to work, but I was never thrilled with the pwm signals on the scope. Doesn't the MS3 have the 3-wire built into the board? Finally, you guessed it, my spark table is still in its infancy. At this point, everything is still on the table for me. How much advance are you running at 900-rpm? More tuning will have to wait until I get a proper air cleaner installed, hopefully by the weekend.
 

dang

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Not to hijack your discussion about fuel, but my wife and installed the rear windshield in my 69 2800cs yesterday. We took our time and used some patience and it went really well. I was pretty excited to get it in!

Dan
 

Sven

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Dan - My experience installing the rear window last year was that it kept wanting to slide upwards so the main trick was to keep the bottom in place and never let up on the downwards pressure. This was not the case at all in the front. They were both quite a workout to install.

David - For the 3-wire driver try Glensgarage.com. That is the driver board I used when I was running MS2/extra. The current MS3X can drive the valve directly so no extra mods required. The pmw % ranges I have are ~35% closed and ~65% open. See the attached graph I made when testing the % valve position and associated rpm. At both open and close there is a range of % where the valve looks closed but is not fully seated (between points A & B and D & E). I was never able to get the test mode of TunerStudio to work with my valve, so tested with the engine running using a spare valve.

I have the idle advance at around 14°. MS3 has a feature where it will drop into a special table just for idle advance and idle VE when certain parameters are met. This is handy for fine tuning.

The collapsing tube causing oscillations seems a bit strange. Does the tube expand and contract with the oscillations? There is small hole in the butterfly plate that will allow some air through even if everything else is closed. I am amazed how little air is needed for idle. With the engine running if I plug this hole with my finger I can stall it. I am considering experimenting with constricting this hole a bit to see if I can slow the rpm's down a bit. The other culprit might be the idle screw and crank ventilation connection (not sure exactly how that works).
 

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vraned

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Thanks Dan, I'm still chuckling. I just read you post to my girlfriend. She just sniffed when I wondered aloud whether your wife had any sisters.

Sven, the motronic butterfly doesn't have a hole it. It's all pwm valve when that thing is closed, and may explain the collapsing tube at low pwm. But it made me think that the easiest way to isolate the root cause would be to crack the throttle and close/block the pwm valve. If it still hunts, it is not the valve.
 
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