Flooding engine on decel

[WASyL]

MS2 2.89 code + TPI adaptor board

My engine fires, idles and runs very well (still tuning) but what i have noticed that when decceling my AFR first goes to around 18-22 but then in as second or two gets and stays to 13-14 what floods it and car wont idle and die. Any ideas why ?

also my injectors are Ford SVO 30# and was wondering what is Injector Opening Time(ms) and what value to put for Battery Voltage Correction (ms/V) ?
i do have such spec for my injectors (see link) but i do not understand it

http://www.fordracingparts.com/parts/ic ... 3-b302.pdf

MSQ attached

Best regards

[trakkies]

Just a guess - but when the engine is slowing on a closed throttle you get a very high vacuum, so the VE table will go to parts not used with the engine under load? Your VE table seems to confirm this.

[WASyL]

good guess, i'll check that, any other ideas ?

best regards

[Hahns5.2]

Yeah looks like there's probably too much fuel in the decel areas of the VE table. If you run the "extra" code you can actually cut fuel during over run.

[WASyL]

well i preffer to stay with standard code, but from what You two say, cutting fuel tottaly on bottom lets say 0-20 kPa @1500-6000RPM and leaning it in range of 30 kPa@1500-6000RPM ?

best regards

[WASyL]

one more thing, form the chart i gave for injectors, my opening time is 1.081 ms described as MINPW(ms) on first table or is it 0.627@13v given at FNPW_OFFSET table?

best regards

[drholl]

Use 1 MS for opening time.

Post a datalog. Or we can only guess. OK, I'll guess.

What's the idle RPM? I assume this is a race only engine. Because of the bin control values and you don't say anything about the cars intended usage. Also you have no "catch bins" at say 500 RPM for fuel or spark. And your kPas don't go very low. Big Cam maybe? Give us a clue as to what you have, and it's intended usage.

My guess. Your injectors are way too small (unlikely) or your required fuel is to long (I suspect). With the numbers I see in the VE and AFR,it's gotta be running about 5% rich.

And I would use "1" in all the bins 1 level lower than the idling kPa. If it idles at 35 put 1's in the 20 kPa bins. If it idles at 40 put 1's in the 20 kPa bins. Here's a good sample from my old cars. I idle at 620 RPM at about 33 kPa. Thing runs Bitchin'.

But it would be better to make another kPa line in the bin say at 30 kPa. See my example, 620 & 33.

Also, I'd say that the engine is flooding out above 4,000 RPM giving a "false lean" reading that you are trying to make up for, with big numbers.

These are just guesses though.
Holl

[drholl]

You can have a look at mine in Success stories.
"16 MPG around town, 502 powered '59 Cadillac"

Holl

[WASyL]

it is street car, i'm having problem to get good idle, if it goes below 900RPM it is very unstable with vacuum at level 60-70kpa (steper at 150-160 steps), @1000RPM it is around 45-55 (steper motor at 110-120 steps) , about my motor:
- SBC 383
- 30lb FORD SVO injectors
- HSR Intake
- 2x58 TB Holey
- heads Trickflow 195cc, Combustion Chamber Volume (cc) 72, valves 2,02/1,6
- cam Trickflow Duration at 050 inch Lift 230 int./234 exh., Advertised Duration 292 int./296 exh., Valve Lift with Factory Rocker Arm Ratio 0.528 int./0.539 exh., Lobe 110
- rockers 1.5
- manual trans

best regards

[drholl]

Since your kPa doesn't get below 40-45 make your Spark table start at 35 and go up by 5 for each line.
Also I would get rid of your columns for RPMs of 5400 and 6000, they are identacl to 5500 before it, and MS will just keep using the last one it sees (5500) if there are no more changes. That will allow you to add a catch bin at say 750 RPM that can have a degree or two added so that if the engine stumbles a little extra spark advance and fuel can be added to pick it back up. Oh and the lines in your VE table of 20 and 35, I'd set them to a "1" value. You usually don't need to add fuel when you are trying to slow down. I cut mine to a "1". And the same for the values around the lower right corner. Set them to "1". Since you can't drive here, why pay for the fuel anyway?
Check out the file I put here it should give you the idea of what I'm trying to teach. Your numbers WILL be different.

Hope this helps.
And always have fun!
Holl

[WASyL]

thanks a milion, i have allready managed to get rid of flooding and engine does not die anymore, but still working on bins and tuning as car still sometimes do weird stuff, but every day is better and better thanks to you, next weekend i plan to do roadtrip over 650 miles with lots of logging so that i get lots of data to analyze . Your help is priceless, i owe you one

best regards