| imaradiostar |
Posted
Monday, Oct 2nd 11:17pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 882
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
...on CIS injection. I'm in the process of doing a Megasquirt II conversion on my friend's Golf GT. Man, this system is neat and it isn't even as cool as the VEMS the Swedish BMW turbo guys are using! I bought an Innovate LM1 wideband O2 sensor with the auxbox for testing and setting the fuel/spark maps on the Golf. I've connected the thing to my 323i so I could learn how to use it and familiarize myself with the connections. This may have been a mistake.
It makes me sad to know just how poorly CIS is metering fuel on my 323i. I've gone to great lengths to retain the stock intake and make the thing look mostly stock under the hood and now I'm starting to not care!
I have a WUR that I made for the car that had been working pretty well, starting and running decently but it seems to run pretty lean at moderate to heavy throttle conditions according to the LM1. I'm using a 2.7 non-turbo Porsche metering housing which I would have thought would be a good match for my 2.7 engine. I have an assortment of different CIS injection components that I'm trying to swap in an effort to improve the situation...but I don't feel very good about it!
Help me out here; am I wasting my time be sticking with the CIS stuff? Are you guys impressed when you see a good running E21 and find out it's still running CIS like JDBeyer or MarquisRex's cars?
Man it would be easy to make up a harness and swap to standalone EFI on my car. I just don't know if I wanna do that though!
jamie |
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| bmw_m_320i |
Posted
Tuesday, Oct 3rd 4:43am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 718
Helena, Montana
none right now :( |
I definately say go with Megasquirt, and if you do the Megasquirt 'n Spark Extra mod, you can have even MORE features like COP, water injection, traction control, Dual Table switching, Nitrous control ect... Its alot more accurate, and you have ALOT more tuning options, and full control of ignition curves. |
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| KenDanielson |
Posted
Tuesday, Oct 3rd 4:48am [Edit] [Quote] [IMS] [View car] |
Junior Member
Post nr. 192
Petaluma CA
'82 320is, '78 320i |
Well, I'm certainly NOT a purest... I like to see an e21 with great running CIS but once you drive one with MS you realize that even correctly running CIS is giving up a lot to programable EFI/Ignition. Besides, it's incredibly fun to tune... and MORE power is ALWAYS more fun!
BTW, I have little use for most of the features that MS can be made to control. I like to keep things simple so there are fewer problems.
ken |
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| bmw_m_320i |
Posted
Tuesday, Oct 3rd 4:57am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 719
Helena, Montana
none right now :( |
Even though alot of features arent needed or used, its nice to have the option 
And with a turbo, some of the extra feaures are no longer options  |
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| imaradiostar |
Posted
Tuesday, Oct 3rd 8:44am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 883
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
Thanks for the input!
I think I'm going to build myself a MSnSe box for my 323i- it seems like the cheapest option. I'll only have to swap the intake and a few other things and I can have most of the rig built outside of the car and just bolt it in. I could easily swap to a late M20 distributor and 60-2 wheel setup in less than an hour. I can use an M50 throttle body which is already equipped with a compatible TPS. I'll probably use an E30 323i intake manifold since it's a nice match for my E30 323i head. I'll probably go with PWM idle control using a two wire bosch idle motor.
One day down the road I'll build myself the all-out VEMS system but I like the idea that I should be able to build the Megasquirt rig with stuff I have laying around at work (old motronic harnesses, big six injectors, etc) and only have to purchase an ECU kit and a few other things.
It'll be nice to know what my engine can really do when it's tuned correctly.
Does anyone know how to correctly implement knock sense based timing control in MS?
jamie |
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| Madhatter |
Posted
Tuesday, Oct 3rd 11:21am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 70
Australia - QLD
E21, E24, E30 |
its not quite such a quick swap, need to replace part of the front timing case and stuff too  |
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| imaradiostar |
Posted
Tuesday, Oct 3rd 4:44pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 884
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
Hatter, I think you're right now that I put some thought into it. I may have been thinking big six.
I think earlier baby six motronic cars (88) may have used a rig more like the big six- bracket bolts over top of the timing cover. I don't recall for certain though.
jamie |
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| bmw_m_320i |
Posted
Tuesday, Oct 3rd 9:19pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 720
Helena, Montana
none right now :( |
if you use an EDIS setup, you dont need to replace the timing cover since you wont need a dizzy cap |
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| Gabi_323i |
Posted
Tuesday, Oct 3rd 11:42pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 117
Bucharest, Romania
11/80 323i 2.7i Motronic 1.3 |
anyone knows if m50 motronic can work on m20 motor? |
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| imaradiostar |
Posted
Wednesday, Oct 4th 7:06am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 886
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
it could be done but MS is likely to look cleaner.
jamie |
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| JDBeyer |
Posted
Wednesday, Oct 4th 8:33am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 228
N. Humboldt county Ca.
82 323i on steroids |
I am going though the same thing Jamie.
I hate to do it but the KJET is so damm rich on my car to make good power.
And I to have used many different AFM and Fuel dist./WUR combinations
I use the PLX R500 to moniter whats up and I did a LOT of dyno time a few weeks back and the power is best with a AFR of 12.0 at the top end.. I mean black smoke!!
I leaned it out and the H.P. just went away..
The kjet just works best..for me.. when it's way to rich, It is making some nice HP/Tourqe #'s but black smoke is not cool
I am thinking I will have to change, Kjet is just leaving to much power, and fuel, on the table!!
Ken's been trying to tell us!!!
Jeff |
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| Marquis_Rex |
Posted
Sunday, Oct 8th 4:59am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 481
UK
BMW 323i 2.7-as featured in Total BMW Nov 2002,Porsche 911/993TT |
Hi guys, I guess alot of it comes down to personal choice.
My E21 has other major issues other than it's engine- namely it's so rusty that it isn't earthing properly! So the bodywork will take priority for now.
I've known for a while that I'm throwing away torque, power and fuel economy or at best making a compromise.
However over the past few weeks, I've been focusing on my 993 Turbo and I'm horrified, no actually appalled at the over-complexity. The Turbo plumbing has disintegrated and the Turbo charger intermediate bearing housings for the Turbos are cracked. One of the "vacuum" actuators for the waste gate controller mal functioned also and the engine would no longer rev because as the flow through one of the Turbos was no doubt going above mach 1 and choking.
This is a low owner car with full service history and low mileage (less then 50K). I'm horrified. This wouldn't have happened on a 1985 930 Turbo with it's simple ignition, injection and Turbo system. I've managed to access the OBD system and have even gotten hold of the a2l file to understand the ECU strategy of the Motronic 5.2 injection. It's very complicated, much like the cars I've helped develop. It's not inspiring for me at all. I hate to think it but I don't think modern German cars are as reliable relative to the competition as they once were- they're way too complex...
Of course, this doesn't mean that your projects need be unreliable if you plumb in megasquirt.
However the way I feel at the moment I'll probably be happy to sacrifice some optimisation of mpg/Bhp/torque....for simplicity, robustness and durability....may be it's as much a political statement in favour of retro car simplicity as much as anything else...  |
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| ichiwan2 |
Posted
Sunday, Oct 8th 5:15am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 243
Kuala Lumpur, Malaysia
BMW320/6(e21) |
That is exactly why I love my e21. If I were to get a Porsche, it would be the 930. Nothing beats the simplicity of the cars from the mid-80s and older. |
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| melloh |
Posted
Sunday, Oct 8th 12:29pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 429
California, USA (San Jose)
1980 320is, 1991 318is |
Dude... the e21 is complex for me. New cars are like when I saw Star Wars as a toddler. Perhaps bmw (and other premium euro brands) is too caught up in the 'gizmo-wars'. Roundel recently displayed bmw's braggin rights as having the most gadgets or something like that. of course, they didn't mention reliability and functionality. The japanese car companies have got the right idea IMO. Even in their cheap cars, MP3 hook-up devices are standard or a REASONABLY priced option that works seamlessly w/ full functionality (unlike bmw's ipod hookup... somewhat seamless and almost fully functional and a ball-buster in price and installation). Oh.. and PLEASE... can we have th driver-oriented dash back. PRETTY please? in the M-cars and sport coupes at least???!?!?!?!?! I think I should be an honorary member of the ol' fart's club (i'm only 40 years ealry). |
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| bmw_m_320i |
Posted
Tuesday, Oct 10th 4:02am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 722
Helena, Montana
none right now :( |
simplicity is nice, but I find I'm not happy unless I'm frustrated by it, which usually happens to be a E39 after it were jumpstarted backwards 12 times by a dump truck  |
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| imaradiostar |
Posted
Wednesday, Oct 11th 3:38am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 891
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
Megasquirt is ideal in many ways- it can be kept very simple and as you get braver you can install or utilize more features. The more I learn the more I like it. I'm just finishing the Golf install and though it's a pain to dial in the enrichments and tables it seems like it'll run much better than the factory ECU did on that car.
I like the idea that there is a bare minimum of components and everyone is using essentially the same ECU with slightly different configuration.
My cousin just bought a Euro E28 that isn't running right- some sort of fuel injection/ignition issue. I may wire up a spare E28 engine harness for megasquirt and bring it along just in case! Between that, my portable toolbox and my laptop I'm pretty confident I could get us home even if the factory ECU is toast.
jamie |
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| imaradiostar |
Posted
Thursday, Nov 23rd 4:26am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 948
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
OK, update if anyone cares.
I wanted (for now anyway) to see how well I can get the CIS rig to run. I gathered up most of my warm up regulator components and tinkered until I finally built a usable unit. It doesn't perform perfectly during warmup or while idling at lights and such but it works great while actually driving!
Under heavy acceleration control pressure drops to around 35 psi- this makes for an air fuel ratio around 12.5:1 at higher rpm. I may be leaving a little power on the table but I have room to lean things out a bit yet. While cruising the AFR is around 15:1, especially between 2 and 3 thousand rpm. This makes for decent fuel economy at reasonable speeds. Control pressure while cruising hovers around 43 psi, sometimes more, sometimes less. Once good and hot the car idles richer than I'd like, around 13:1. I think there is a decent reason for this.
Interesting thing to note- while testing the WUR with the engine not running I noticed that the vacuum enrichment feature works great but with a flaw. As I increased the vacuum on the WUR with my little hand-operated vacuum pump the control pressure went up and up (up to 45-46 PSI) then it started to go back down again (to around 42-43, maybe less). All I can figure is that that vacuum is great enough that fuel diaphragm is pulled down by the excessive vacuum, causing the control pressure to go down again after the initial rise. As this relates to the engine running, throttle transitions that create moderate vacuum result in high control pressures while idling or decelerating seems to result in lower than desirable control pressures.
I'm thinking I might try to make a "vacuum limiter" for the line connecting the WUR to the intake- perhaps a small in-line metal T fitting with an adjustable orifice at one end and a filter to prevent filth from blocking the orifice. I could use this to set a "max vacuum level" so that the mixture would be a little leaner at idle. Hopefully it wouldn't negatively effect cruising speeds or full throttle enrichment.
Keep plugging CIS nerds! Maybe someone out there has some idea about this stuff. I need to find some Porsche racers from the late 70's- they probably had all of this figured out perfectly!
jamie |
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| bmw_m_320i |
Posted
Thursday, Nov 23rd 7:36am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 733
Helena, Montana
none right now :( |
you could making a vaccum limiter that is only active at idle. install a switch to control a purge valve that would reroute vaccum through a limited circuit, which may be as easy as using smaller hose |
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| Marquis_Rex |
Posted
Thursday, Nov 23rd 12:23pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 497
UK
BMW 323i 2.7-as featured in Total BMW Nov 2002,Porsche 911/993TT |
| imaradiostar wrote: | .....
..... While cruising the AFR is around 15:1, especially between 2 and 3 thousand rpm. This makes for decent fuel economy at reasonable speeds. Control pressure while cruising hovers around 43 psi, sometimes more, sometimes less. Once good and hot the car idles richer than I'd like, around 13:1. I think there is a decent reason for this. |
That's very interesting!
How difficult would it be to run it even leaner during cruise? I reckon the engine would be ok up to 16:1 without serious misfires on transients
| imaradiostar wrote: | Interesting thing to note- while testing the WUR with the engine not running I noticed that the vacuum enrichment feature works great but with a flaw. As I increased the vacuum on the WUR with my little hand-operated vacuum pump the control pressure went up and up (up to 45-46 PSI) then it started to go back down again (to around 42-43, maybe less). All I can figure is that that vacuum is great enough that fuel diaphragm is pulled down by the excessive vacuum, causing the control pressure to go down again after the initial rise. As this relates to the engine running, throttle transitions that create moderate vacuum result in high control pressures while idling or decelerating seems to result in lower than desirable control pressures.
jamie |
If the control pressure went up with increasing vacuum- wouldn't that lean off the mixture? I'm confused, so are you saying during transient tip-ins the control pressure initially rises and then goes down? or that during the moderate vacuum of transients the control pressure goes down for a richer mixture but rises with MORE vacuum for over run leaness and idle leaness?
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| imaradiostar |
Posted
Friday, Nov 24th 1:53am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 952
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
At atmospheric the control pressure was around 35 PSI.
At about 5 inches mercury it was 45 PSI.
At 10 inches mercury control pressure drops again to around 42 psi.
I don't know for sure but I believe I can work around this- the above mentioned ideas are great. I may even work out a mechanical air bypass that runs at idle. Whatever I do I'd like to have a minimum of components and complexity.
I've already been working on leaning the car out again but I'm fighting an overheating problem at the moment- I suspect my water pump impeller is spinning on the shaft because the thermostat is opening but even when forcing air over the radiator the engine gradually overheats. Thank goodness I have several different cars to drive!
jamie |
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| JJG323 |
Posted
Friday, Nov 24th 2:57am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 1285
Reading MA USA
1979 BMW 323i |
Jamie,
I am swapping the motronic into my 323i along with a 2.8 m20 1990 stroker.
Then down the line I am either going megasquirt...or autronic..I have not the money yet..but I intend to do it.
later,
J |
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| imaradiostar |
Posted
Friday, Nov 24th 6:23am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 953
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i |
not to throw a wrench into the works joe but have you looked at DTA or VEMS?
jamie |
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