ms required fuel

90volvo · 11-25-2020, 10:21 PM

Ok, I have installed my new engine. Before I was running megasquirt with 650cc injectors on E85. My required fuel was at 13.5, I know my injectors were to small. My new engine I installed 1000cc injectors. I tried to start it tonight but it immediately flooded the engine. Thinking about it I think I need to lower the required fuel. But unsure where to start. The megasquirt says 3.9? But thats for gas so would I be correct to go with like 6.0 or 8? I was smart and pulled the plugs and letting cylinders to dry out. I also added some gas cause it cold here and know e85 can be cantancerous in winter. Heres my specs.

90 240
B230ft
Stage 3 cam
larger valves and ported head
custom header
Turbo GTX3067r
3 inch ex.
1000cc injectors
3 inch intercooler piping
Big intercooler
External wastegate
External BOV

Dirty Rick · 11-25-2020, 10:41 PM

If you don't have a lot of compression E85 doesnt want to fire on a stone cold motor.
A blast of spray cleaner will help get it fired for setup.

You are likely good at 6 on the reqFuel, if the reqFuel gets too big you will loose granularity at the low end of the table.
If the low end of the table gets too small, reduce the reqFuel.
Make this decision early on as changing the reqFuel affects all areas of the VE table.
Changing the reqFuel means the entire VE table will need to be re-set.

90volvo · 11-25-2020, 10:48 PM

Thanks for advice. Its about 40 degrees out. I forgot about E85 not liking the cold.

bobxyz · 11-25-2020, 11:04 PM

I think you need to change the AFR in the ReqFuel popup from 14.7 to 9.8? for E85, and change to your bigger injector size. This should give a more reasonable starting value.

90volvo · 11-25-2020, 11:08 PM

Will do thanks

Dirty Rick · 11-25-2020, 11:10 PM

You can leave the Stoich and AFRs set to gas numbers so you don't have to translate.
Lambda is Lambda, it does not change with the fuel.
Remember AFRs are not measured, they are calculated from Lambda.

Injector dead time settings will come into play in the idle area also. So get those right as possible early on.

JohnMc · 11-25-2020, 11:14 PM

What I was going to say. The wideband doesn't know what fuel you're using. It just knows stochiometric, rich, lean. Tune to 14.7 still.

bobxyz · 11-25-2020, 11:40 PM

For E85, change the AFR _only_ in the reqfuel popup. For anything else that uses the WB02 sensor, e.g. AFR table, leave the AFR at 14.7.

90volvo · 11-26-2020, 08:09 PM

So the Megasquirt said 6.8 on required fuel. But it wouldnt hardly run at that was super rich. I started leaning it out and finally got it to run smooth but was all the way down to 2.5? So thought maybe the tables need to be changed? Thanks

90volvo · 12-02-2020, 12:41 AM

Figured my problem out with they help of others. The kpa were running like 300 so it was way off. Traced it down to the Map sensor, it was either bad or wrong one got put in right box. Anyways now I can move on with tuning. Thanks

JohnMc · 12-02-2020, 10:21 AM

Quote:

Originally Posted by bobxyz

For E85, change the AFR _only_ in the reqfuel popup. For anything else that uses the WB02 sensor, e.g. AFR table, leave the AFR at 14.7.

That does make a lot of sense, thanks for the correction.

11-25-2020, 10:21 PM	#1
90volvo Board Member Join Date: May 2017 Location: Eldorado Springs Mo.	ms required fuel Ok, I have installed my new engine. Before I was running megasquirt with 650cc injectors on E85. My required fuel was at 13.5, I know my injectors were to small. My new engine I installed 1000cc injectors. I tried to start it tonight but it immediately flooded the engine. Thinking about it I think I need to lower the required fuel. But unsure where to start. The megasquirt says 3.9? But thats for gas so would I be correct to go with like 6.0 or 8? I was smart and pulled the plugs and letting cylinders to dry out. I also added some gas cause it cold here and know e85 can be cantancerous in winter. Heres my specs. 90 240 B230ft Stage 3 cam larger valves and ported head custom header Turbo GTX3067r 3 inch ex. 1000cc injectors 3 inch intercooler piping Big intercooler External wastegate External BOV __________________ 90 Volvo 240-my current setup. B230ft rebuilt -MS-Turbo-E85 1985 240 Work in progress. sons car- 93 240-15g turbo-chipped-95,000 miles. Slick car Leave feedback- http://forums.turbobricks.com/showthread.php?t=355413

11-25-2020, 10:41 PM	#2
Dirty Rick Board Member Join Date: Apr 2013 Location: Cornholio, OR	If you don't have a lot of compression E85 doesnt want to fire on a stone cold motor. A blast of spray cleaner will help get it fired for setup. You are likely good at 6 on the reqFuel, if the reqFuel gets too big you will loose granularity at the low end of the table. If the low end of the table gets too small, reduce the reqFuel. Make this decision early on as changing the reqFuel affects all areas of the VE table. Changing the reqFuel means the entire VE table will need to be re-set. __________________ I don't know who I am when I am somebody else. Last edited by Dirty Rick; 11-25-2020 at 11:06 PM..

11-25-2020, 11:14 PM	#7
JohnMc PV Abuser Join Date: May 2004 Location: St. Louis	What I was going to say. The wideband doesn't know what fuel you're using. It just knows stochiometric, rich, lean. Tune to 14.7 still. __________________ '63 PV Rat Rod '93 245 16VT Classic #1141

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11-25-2020, 10:48 PM	#3
90volvo Board Member Join Date: May 2017 Location: Eldorado Springs Mo.	Thanks for advice. Its about 40 degrees out. I forgot about E85 not liking the cold.

11-25-2020, 11:04 PM	#4
bobxyz Board Member Join Date: Aug 2014 Location: Boulder CO	I think you need to change the AFR in the ReqFuel popup from 14.7 to 9.8? for E85, and change to your bigger injector size. This should give a more reasonable starting value.

11-25-2020, 11:08 PM	#5
90volvo Board Member Join Date: May 2017 Location: Eldorado Springs Mo.	Will do thanks

11-25-2020, 11:10 PM	#6
Dirty Rick Board Member Join Date: Apr 2013 Location: Cornholio, OR	You can leave the Stoich and AFRs set to gas numbers so you don't have to translate. Lambda is Lambda, it does not change with the fuel. Remember AFRs are not measured, they are calculated from Lambda. Injector dead time settings will come into play in the idle area also. So get those right as possible early on.

11-25-2020, 11:40 PM	#8
bobxyz Board Member Join Date: Aug 2014 Location: Boulder CO	For E85, change the AFR _only_ in the reqfuel popup. For anything else that uses the WB02 sensor, e.g. AFR table, leave the AFR at 14.7.

11-26-2020, 08:09 PM	#9
90volvo Board Member Join Date: May 2017 Location: Eldorado Springs Mo.	So the Megasquirt said 6.8 on required fuel. But it wouldnt hardly run at that was super rich. I started leaning it out and finally got it to run smooth but was all the way down to 2.5? So thought maybe the tables need to be changed? Thanks

12-02-2020, 12:41 AM	#10
90volvo Board Member Join Date: May 2017 Location: Eldorado Springs Mo.	Figured my problem out with they help of others. The kpa were running like 300 so it was way off. Traced it down to the Map sensor, it was either bad or wrong one got put in right box. Anyways now I can move on with tuning. Thanks