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Fred's "Hotel Hyundai" 1988 Stellar! (3rd)
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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Car had been running badly since I got it, but better once on FreeEMS and with a better decoder angle and so forth, but still not 100%. Today I got stranded twice and nearly stranded a third time. FreeEMS checked out fine (proven via ignition out LED flashing in harmony, no laptop handy), so it had to be fueling related as the tacho also worked, and that's coil driven.
The first time, I just happened to have a philips and the fuel hose just happened to have a hose clamp, so I pulled it off, pumped fuel into the grass, and it ran fine.
The second time the same events unfolded.
The float in the bowl must be sticky or half full of fuel, I guess. Need to put some time into that tonight and see what I can see.
I have a few tweaks to make to the ignition/ECU setup to make it nicer, too. All in good time. Reliability first.
_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Mon Dec 16, 2013 8:16 am |
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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Lots of pieces of carb all over the engine bay. Off the road yet again. Not FreeEMS' fault, though. Thank goodness I fixed the LED for ignition out, that was worth its weight in gold today. I either lost a bit of carby, or it dissolved, or Presto lost it, or something, as the float setup seems to be incomplete or incapable of restricting flow at all. Something ain't right. Grrrr.
ITBs + engine bay mounted fuel pump = near future? Fucking carbs suck.
What would it take?
Find ITBs and injectors for them (have these) Obtain a low-power inline fuel pump (don't have this) Obtain a stump inlet manifold to use (so as to keep the carby one available for returning to stock later) (don't have this) 4 pieces of hose to join stumps to ITBs (don't have this) 8 hose clamps to join stumps to ITBs (don't have this) 5 FETs to control the injectors and pump relay (have these) 1 day to do the required work (don't have this) 3 more days to be realistic (definitely don't have this)
On the other hand, if the carby is missing a necessary part, I could screw around with it indefinitely and not make progress. Ugh.
Hmmm.
_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Mon Dec 16, 2013 11:36 am |
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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Fred wrote: I have a few tweaks to make to the ignition/ECU setup to make it nicer, too. All in good time. Reliability first. For the record: - Fix decoder angle to match reality established in above screen shots.
- Verify that signal from opto to CPU is robust (touching scope probe to this CPU pin caused loss of sync and should not)
- Change base timing to be 170 (-10) and setup dizzy for 10BTDC cranking.
- Lower hardware based dwell threshold and/or add hysteresis to its use (Use up to 600, start using again below 400, for example)
- Lower full load timing from 2500 to 4k where it currently rattles on 91RON
And throw carby out the window.
_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Mon Dec 16, 2013 11:42 am |
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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Took apart carby, nearly lost parts from it (some into engine, others into wrong places), put it all back together, warmed it up, revved it up, poured half a litre of water down its throat while revving, took it for a "spirited" drive, returned to base satisfied that next time it fails on me, I'll have sufficient tools handy to fix the issue. Drove nicely, though, so that's something. Unsure why, so I've almost certainly NOT fixed anything.
Manifold is a yucky shape for ITBs, though with a bit of TIG love from someone friendly, it could happen.
_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Tue Dec 17, 2013 2:08 am |
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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Currently running 83/97 degree split for the decoder, which is a LOT closer than the 69/111, but from the data above (udpated), we can see it's still not right, here are the numbers: http://stuff.fredcooke.com/hotel.fine.s ... MAG005.pngCPU high 20ms exactly CPU low 19.3333ms roughly 762.711864407 RPM 180 * (20 / 39.33333333) = 91.52542 degrees high 180 * (19.33333333 / 39.33333333) = 88.47457 degrees low http://stuff.fredcooke.com/hotel.fine.s ... MAG008.png1757.8125 RPM CPU high 8.73333ms CPU low 8.33333ms 180 * (8.73333333 / 17.06666666) = 92.109 degrees high 180 * (8.33333333 / 17.06666666) = 87.891 degrees low http://stuff.fredcooke.com/hotel.fine.s ... MAG009.png1757.8125 RPM CPU high 8.6666666 CPU low 8.4 180 * (8.6* / 17.06666666) = 91.4062 degrees high 180 * (8.4 / 17.06666666) = 88.5938 degrees low http://stuff.fredcooke.com/hotel.fine.s ... MAG010.png1717.55790746 RPM CPU high 8.33333ms CPU low 8.73333ms 180 * (8.33333333 / 17.06666666) = 87.891 degrees high 180 * (8.73333333 / 17.06666666) = 92.109 degrees low http://stuff.fredcooke.com/hotel.fine.s ... MAG011.png3351.95530726 RPM CPU high 4.25ms CPU low 4.7ms 180 * (4.25 / 8.95) = 85.4749 degrees high 180 * (4.7 / 8.95) = 94.5251 degrees low http://stuff.fredcooke.com/hotel.fine.s ... MAG012.png3488.37209302 RPM CPU high 4.1ms CPU low 4.5ms 180 * (4.1 / 8.6) = 85.8140 degrees high 180 * (4.5 / 8.6) = 94.1860 degrees low This is the natural variation of the engine with its sensor config. Slop in the dizzy drive, asymmetrical lag in the hall sensor setup, slop in the shaft causing clearance variation, etc. Still, though, in no currently measured case, is 83 degrees correct. I just setup the car with 10BTDC cranking, 170 offset, and used hard timing to 1500 to set the timing of the engine. Thus any error in timing is purely down to the above variation and mismatch with the decoder angle. To match the 3500 RPM section, we're looking at 86 degrees decoder angle, but to match idle we're looking at 91, and to match 1700 odd, we're looking at about 90. What I'll do is go down and warm up the car, do a sweep up to rev limiter slowly, record the log, update the firmware to 86, repeat, update the firmware to 90, repeat, and review the time tolerance figures, then choose one. Fred.
_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Tue Dec 17, 2013 11:54 pm |
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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83 bad 86 bad but better 90 much better but not good, will live with this
Drives OK now, logs OK now, comfy commuter project complete. Anything further is lowering the timing in the high load regions. Any JAFAs keen to volunteer to drive or tune for me?
_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Wed Dec 18, 2013 12:37 am |
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Wed Dec 18, 2013 1:18 am |
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Fred
Moderator
Joined: Tue Jan 15, 2008 2:31 pm Posts: 15078 Location: Home sweet home!
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EFI manifold ordered! If it's not very good, I'll butcher it and add ITBs. What can I do for a 50 - 100lph fuel pump? Any ideas? 
_________________DIYEFI.org - where Open Source means Open Source, and Free means Freedom FreeEMS.org - the open source engine management system FreeEMS dev diary and its comments thread and my turbo truck!n00bs, do NOT PM or email tech questions! Use the forum! The ever growing list of FreeEMS success stories!
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Thu Jan 09, 2014 11:25 am |
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Dan
LQFP144 - On Top Of The Game
Joined: Tue Mar 02, 2010 2:33 pm Posts: 1201 Location: Australia
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get a walbro or bosch, even a bosch clone or something  cheap enough IMO  probably go in-line external though, as I doubt there is an intank one there already due to the shitty card configuration, as it will make installation relatively easy 
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Fri Jan 10, 2014 3:19 pm |
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Impregacy
QFP80 - Contributor
Joined: Fri Feb 26, 2010 12:15 am Posts: 67
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Bosch 044 or walbro 255 are three times too big. You don't want to recirculate that much fuel unnecessarily heating all the fuel in the tank (bad). Even if you plan to make a "returnless" system where the regulator is near or in the tank, I think a pump that size itself would do a lot of heating. I recently acquired an Audi A6 in tank unit from a pick-a-part yard here in the States for $10. It is a nice small bosch unit. It looks to have a commonly available banjo fitting on the high pressure side. Something like that might work for your situation. You can have this one if you pay for shipping. Can I take this opportunity to make a feature request on the topic of pumps that are too big? PID calculated PWM output for the fuel pump, perhaps with TPS value as the input or a fuel pressure sensor.
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Fri Jan 10, 2014 6:32 pm |
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