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Under new (engine)management

Discussion pertaining to positive pressure E28s.
M. Holtmeier
Posts: 3036
Joined: Mar 11, 2007 3:06 AM
Location: Josephine, Texas

Post by M. Holtmeier »

I was just thinking about the timing today. I'll have to check that. Tps is working, I think my low idle count was like 44. A/F was right around 13. The engine acts like someone pulls a vacuum hose of and sticks it back a few seconds later. The A/F even goes a little leaner (14.5-15) when it happens.
This may be a dumb question, but if I crack the idle valve open a little at idle to smooth things out, MS closes it back off as soon its off idle right? I can see that if it were set in closed loop but just don't know in open loop.
Maddog
Posts: 191
Joined: Feb 12, 2006 12:00 PM
Location: Atlanta, GA

Post by Maddog »

What code are you running? You are just setup for warmup right now...correct?
M. Holtmeier
Posts: 3036
Joined: Mar 11, 2007 3:06 AM
Location: Josephine, Texas

Post by M. Holtmeier »

I thought I loaded 029v, but I sure see a lot of 029q in the msq info. I'm not much of a computer programmer, building the hardware seems more straightforward to me. I see that 029y4 just recently came out. I'm just running warm up right now. The more I read about it I'd love to get closed loop running, but the instructions warn you about using it with a bad tune.
M. Holtmeier
Posts: 3036
Joined: Mar 11, 2007 3:06 AM
Location: Josephine, Texas

Post by M. Holtmeier »

Got the idle straightened out tonight. I think a new set of plugs was the major contributor. It sat all weekend after getting it to idle for the first time. Today it would only run on about 4 cyl's. I thougt my warmup setting were bad but it ran crappy all the way to op temp. I think the 62 lb/hr inj's are tricky for first timers! After the plugs were in I was tuning.
Verified 0 degrees at O/T mark on the balancer(That's right, right?) with the fixed angle set to 0. I read where some of you guys were getting your idle to around 13.5 afr and only 14 degrees timing. I was at 16 degrees and couldn't get any leaner than 13 before it started stumbling. It pulls 37kPa. I tell you what, where it is now is sooo smooth. I ended just shutting the IAC off after warmup, I don't think it's responding right. I adjust the duty cycle up and down from 0-10,10-20 and it has no effect on idle until I throttle it a couple of times. It seems to work ok while the engine is warming up though. I'll mess with it more later. I ended closing the t.b. back down to around 950rpm. This car and my old 528e never idled like this stock! Maybe my LC-1 is a little off or something, I don't know. I know in megatune it isn't right because it wants 1-5 volt input and I have the LC-1 for a 1-2v(1v=10.00, 2v=20.00) to run my digital display in the dash. Is there a way to change the MS to read like my dash gauge or do I need to run the second output to MS and configure the lc-1 accordingly?
Next problem( If you don't mind :) ) I can rev the engine very slowly to 2500 rpm, fuel and spark are not perfect but smooth up to that point. All of a sudden the tach signal starts dropping out. I have the VR sensor set about 4mm from the balancer. I used one of the old timing sensor leads from the bell housing to run from the sensor conn to the ms. Black wire to pin 2 and the yellow? wire to pin 24 (+). The sheild wire is grounded.I'm thinking either the leads are switched, the sensor is not adjusted right or the it is bad.
Thanks for all of your help :D
turbodan
Posts: 9246
Joined: Jan 09, 2007 10:19 PM

Post by turbodan »

The problem I was having with my tach was solved by reducing the ignition dwell. I had been playing with it and I ended up with 2ms max dwell with 2ms accel enrichment. This setting caused the gauge tach to jump around senselessly at high revs. I dont know why. When I went back to 2ms max dwell and 1ms accel compensation, it worked fine again.

If you're losing the rpm signal to the MS, I would move that VR sensor closer to the wheel. 4mm is a pretty big gap. My stock M20 2.5i sensor and bracket have the tip of the VR sensor less than 1mm away from the toothed wheel. I bet thats your problem. You could measure the gap with a fat feeler gauge with the stock positioned VR sensor.
M. Holtmeier
Posts: 3036
Joined: Mar 11, 2007 3:06 AM
Location: Josephine, Texas

Post by M. Holtmeier »

Well adjusting the sensor definately helped out. I can rev it up to about 3800 before the tach starts dropping out again. I was reading that maybe I should have jumpered the TSEL to the VROUTINV instead of the VROUT for an inverted vr signal. (See step 51 in V3 assembly). I don't know if having this jumpered incorrectly would even let my engine idle this good and rev up to 3800. Or possibly this a case of having the vr wires backwards? I could be looking at this the wrong way too, the car sound like an old points dist- backfiring out the exh. I've played with dwell setting, going from 2.0-2.5 running and it doesn't seem to make a big difference. Afr stays rich(11.5-12.5) and the timing is set to a constant 25 at 3-4k rpm. It's the tach signal that starts jumping to 6500, very irratic. I though I'd ask if someone knew these different scenarios before making any changes.
M. Holtmeier
Posts: 3036
Joined: Mar 11, 2007 3:06 AM
Location: Josephine, Texas

Post by M. Holtmeier »

Ok I got it.
I verified my sensor signal was NOT dropping out, I had steady a/c voltage at all times while the engine was running.I had to move the TSEL jumper to the VROUTINV and swap my vr sensor wires around. My (+) sensor wire was yellow and it now goes to ground at the MS, black wire to pin 24 of the MS. Engine revs happily to 5800-that's as far as I wanted to go for now.
turbodan
Posts: 9246
Joined: Jan 09, 2007 10:19 PM

Post by turbodan »

5800? What kind of motor do you have there?
M. Holtmeier
Posts: 3036
Joined: Mar 11, 2007 3:06 AM
Location: Josephine, Texas

Post by M. Holtmeier »

M30b24 535i. Redline's a little over 6k I think.
This car and my old 528e never idled like this stock!
Maybe I was misleading with this statement. I remember my old eta motor was ~4500.

My first bimmer- 86 528e
Image
j9fd3s
Posts: 37
Joined: Apr 08, 2006 12:25 PM
Location: menlo mazda
Contact:

Post by j9fd3s »

grsmonkey wrote:Has anyone ever used the "Hybrid Alpha-N" that combines map and tps for a boosted engine?
most stock ecu's do this, and most aftermarket ecu's can do this.

it gives you finer control over idle and low speed/load.

it also gives you the ability to fine tune the heavy load maps, ie if you're going up a hill, and boost is high, but throttle position is low.

setup time is an issue, it takes time to tune it.
M. Holtmeier
Posts: 3036
Joined: Mar 11, 2007 3:06 AM
Location: Josephine, Texas

Post by M. Holtmeier »

I've been driving the car for about a week now. It's running so good I decided to take a vacation from work to finally enjoy the fruits of my labor.
I've been doing alot of datalogging and tuning. The around town streetability is very smooth now and the idle is still better than stock. I have the MS optioned for dual boost tables running closed loop kpa targets and a switch in the dash. The low setting is 165 kpa, the upper setting is 205. I haven't even switched it to high yet. The boost peaks at about 15 then settles down to 11 and varies from 9-12. I currently have my boost setting at 39 Hz, 10ms update, 75% proportional gain and 20% differential gain. So far I've upped the prop. gain and diff. gain a little but haven't done alot of WOT tuning. I though I'd ask to see if the closed loop really works that well in MSI extra. I can always omit the switch and use standard duty cycle targets if they prove more reliable.
One other thing I'm having trouble with is hot starts. So far, I haven't seen weather under 80. I have the cranking/priming setting along with IAC set to start great at 80- ~160. It's when I shut the car off, go in somewhere for an hour or less and try to restart the car. It doesn't die out but comes so close that the cranking setting come active again. It starts up, idles quickly to 1200rpm then stumbles around for a second then slowly picks back up- all happening within about 3 seconds. If I shut the car off at op temp and restart it right away, it fires right up. I just can't figure out that 170- 185 window. I have my idle valve upper/lower temp set to 185, 50 respectively, lower temp at 70% dc operating the valve at 200Hz to try to help cover that hot range. It helps slightly. Maybe the idle valve is sticking or I need to use the Glen's garage idle circuit and go for closed loop op? I know you guys always get me pointed in the right direction! :D
Nebraska_e28
Beamter
Beamter
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Post by Nebraska_e28 »

Good news to hear man!
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