I am having trouble starting up on occasion and finally had an idea. I wired my wideband O2 sensor so I could manually warm it up before I started the car. Then I started a log file and cranked the car over. Luckily I had the starting problem this time and was able to record it.
The car will fire on the first try, then stumble. Crank a second time and I need to hold the throttle open slightly for about 30 seconds before it will idle on its own. If you open the datalog and look at the AF graph between 29 and 30 seconds you see it jumps up from 10.xx to 14.xx however I can't find why it jumps like this. The pulsewidth seems to remain the same.
If there is something I am overlooking please let me know. I have included my MSII with V2.33 embedded code. The ASE does turn off just after 30 seconds, however it is after the AF ratio balances out.
Thanks in advance, I'd like to be able to start the car in one try soon.
Odd a/f ratio jump after startup, log file included.
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Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Odd a/f ratio jump after startup, log file included.
1994 Ford Probe GT 2.5L, T04B, 550cc, MS2.
1981 Ford Fairmont, 351c, MS1.
1981 Ford Fairmont, 351c, MS1.
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detcollector
- MegaSquirt Newbie
- Posts: 12
- Joined: Tue Oct 26, 2004 3:41 am
- Location: UK
IMHO
Try reducing your after start enrichment to 120 and reduce the warm up enjrichment by 10%.
Also set the decel fueling to 100% instead of 90% to help with tuning. I can't remember what its called in MS but its the opposite to the accel enrichment. You might want to turn off or reduce Accel enrichment as you are using it in this datalog so you might be over sensetive.
Basicly it looks like when the engine gets to a "run" condition you are over fueling. Thats a combination of your warm up + after start + VE table. To keep the engine running you are opening the throttle and allowing extra air in. When the engine has warmed up and the after start reduced the numbers are becoming sensible. So its those 2 parameters you need to adjust - and in this case reduce.
Hope this helps.
Try reducing your after start enrichment to 120 and reduce the warm up enjrichment by 10%.
Also set the decel fueling to 100% instead of 90% to help with tuning. I can't remember what its called in MS but its the opposite to the accel enrichment. You might want to turn off or reduce Accel enrichment as you are using it in this datalog so you might be over sensetive.
Basicly it looks like when the engine gets to a "run" condition you are over fueling. Thats a combination of your warm up + after start + VE table. To keep the engine running you are opening the throttle and allowing extra air in. When the engine has warmed up and the after start reduced the numbers are becoming sensible. So its those 2 parameters you need to adjust - and in this case reduce.
Hope this helps.
Sorry, I haven't been on here recently. I dropped the ASE to 0, pre-warmed my O2 sensor, started the engine and adjusted the cold enrichment until the a/f ratio was in the 14 range. 8 hours later the car cooled off and it started on the first try with no throttle at all - sweet. The next morning it took me 6 tries to get it started - not sweet. argghhh. I'm running out of ideas. One thought I have is that since I am way over-injectored I might be having problems. I can get a set of 480cc injectors pretty cheap, I might have to try them out and see if it helps. Right now my idle pulse width is in the 1.5-1.6 range.
1994 Ford Probe GT 2.5L, T04B, 550cc, MS2.
1981 Ford Fairmont, 351c, MS1.
1981 Ford Fairmont, 351c, MS1.
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mops
- Experienced Squirter
- Posts: 217
- Joined: Sun Sep 25, 2005 4:13 pm
- Location: Auckland, NZ
- Contact:
what I found when datalogging my stock bosh ecu that on cold morning, first start it idles at as rich as 11 afr. with MS i can make it idle on dead cold start at 13, but then it's very easy to stall... kinda feels like it was running lean (a/f showing 13.something).
bottom line is, on dead cold start, you will need significantly more fuel, i.e. run richer for a a brief warmup period. trying to make it run lean there will only result is drivability problems.... just give it all the fuel it needs there.
idle should be tuned when engine is fully wamred up, AND not standing and freereeving the engine in one place, as the underbonned gets very hot affecting air temp in the intake...
at least get idle sorted with bonnet opened up....
bottom line is, on dead cold start, you will need significantly more fuel, i.e. run richer for a a brief warmup period. trying to make it run lean there will only result is drivability problems.... just give it all the fuel it needs there.
idle should be tuned when engine is fully wamred up, AND not standing and freereeving the engine in one place, as the underbonned gets very hot affecting air temp in the intake...
at least get idle sorted with bonnet opened up....
BMW, 1985, E30, 325i, 2-door, 5spd , 127k miles, short shift, MSII, V3/code 2.684/60-2 wheel/MT 2.25, LC-1 wbO2, ignitor module mod driving msd coil/, 3 pin Bosch PWC IAC mod
It has been weeks and I'm still messing around trying to fix this. I started with 0 ase, and adjusted my VE table until I got stable 14:1 a/f at idle. Then I tried adding ase back in. It definitely helps then engine start up, it will pop on the first try with 10% ase, but I have noticed that the engine will not continue to run unless it rev's over 2000rpm the first time it fires. Doesn't matter what else you do, tap the throttle with your foot, make adjustements...etc. It only runs if it rev's over 2000rpm, then it immediately idles at about 700rpm. If it doesn't go over 2000rpm it will either die or idle like crap for 30seconds, then it bounces back to a normal idle at 700rpm.
1994 Ford Probe GT 2.5L, T04B, 550cc, MS2.
1981 Ford Fairmont, 351c, MS1.
1981 Ford Fairmont, 351c, MS1.
my v-8 is set up for idling at 15:1 but after start enrichment of about 130% is used and the warmup curve is almost 150% at 70 degrees f (21c, sorry, that's the coldest it gets out here during the day, hehe) . before i put these high numbers i played with ve entries for a while, without results.
ve at idle should be adjusted with warm engine, for maximum vacuum (lowest kpa reading). After that, leave the ve entries alone. If you have problems starting the engine, go wild with after start enrichment and warmup enrichment.
d.
ve at idle should be adjusted with warm engine, for maximum vacuum (lowest kpa reading). After that, leave the ve entries alone. If you have problems starting the engine, go wild with after start enrichment and warmup enrichment.
d.