E85 Tuning Headaches

[Panoles1]

I recently converted my car to E85 after doing much research and successfully running on 93 octane and meth sprayed. I simply changed my required fuel by changing my AFR settings from 14.7 to 9.8. The car started up fine and even went around the block before it started coughing an carrying on. It went VERY lean at idle and cruise rpm's, so I avoided anything above 100KPA. I had to then adj my FE table SIGNIFICANTLY (doubling the numbers even) to bring the AFR's in-line. I have been slowly tuning the boost areas, but it appears to be very erratic... Meaning, it will be fine and start acting up by going lean again. I generally have to pull over and load another E85 tune to correct this.

It's possible I might have some other issue, but wanted to someone to take a look at recent datalogs and my msq to see if there is anything obviously wrong. The fact that I had to double my 93 tune, even after changing the req fuel concerns me. The attached VE is probably even more jacked as I made attempts to fatten it up.

Could my wideband (LC-1) be taking a crap? I'm running 1000Cc injectors (low imp) and I also have a fuel pressure gauge and can verify that it increases FP accordingly.

I'm open to any suggestions or corrections needed. Thanks in advance.

[Panoles1]

MSQ..

[rabid]

I didn't look at the logs. Is the req fuel now about 30% bigger than the gasoline tune? Are your injectors larger? Duty cycle ok? The tables will change and lean out a bit on some areas and rich in some areas. The spark advance will need to be advanced. E85 loves spark advance. Cold starting will need more fuel. Tons more fuel below about 50 degrees F. Epic levels of fuel below 30 F.

I have a 1600cc engine with 1200cc injectors. It runs around 3.1 req_fuel and makes high vacuum areas of the map a pita. Gasoline was about a 2.2 req_fuel

[Panoles1]

I didn't look at the logs. Is the req fuel now about 30% bigger than the gasoline tune? Are your injectors larger? Duty cycle ok? The tables will change and lean out a bit on some areas and rich in some areas. The spark advance will need to be advanced. E85 loves spark advance. Cold starting will need more fuel. Tons more fuel below about 50 degrees F. Epic levels of fuel below 30 F.

I have a 1600cc engine with 1200cc injectors. It runs around 3.1 req_fuel and makes high vacuum areas of the map a pita. Gasoline was about a 2.2 req_fuel

The required fuel is currently 5.8, when it was previously 3.8. So, it's not quite 30% (25%) than the gasoline tune. I'm running the same injectors, which are 1000CC's. After the switch from gasoline to E85, it started up immediately and I did add some cold starting fuel to help that out. My starting and idling is great. I'm still wondering why I needed to double my VE table, in addition to increasing the req fuel

I'm going to go back to the gasoline VE table and up the required fuel in a bit and see what it does. As far as the duty cycle... I have to admit that I'm not sure what I'm looking at and why it's important. I'll read up on that.

I'm beginning to wonder if my fuel pump (Walbro 255 high pressure) didn't take a crap or pick up crap after the switch over, though I can monitor my fuel pressure and it rises with boost as it should. I could generally hear the pump through the exhaust (2.3 Ford Turbo) and now I can barely hear it singing!

[rabid]

e85 can clean anything out of the tank and plug the filter.

[techsalvager]

why did you use 9.x instead of 14.7 for the req fuel?

[Panoles1]

why did you use 9.x instead of 14.7 for the req fuel?

I did that to change my required fuel for the E85. That's correct right?

[Panoles1]

e85 can clean anything out of the tank and plug the filter.

I thought about that and already changed the fuel filter. Maybe the fuel sock on the end of the pump might be clogged? I'm going to drain the tank in the next day or so and check that out. II;m really starting to "lean" towards a fuel delivery problem, possible created when I added the E85 to the tank.

I notice I can barely hear the pump singing as it normally would. The Walbro pumps in the mustangs are notorious for being noisy and now it's quite. Go figure... I miss not hearing it.

[techsalvager]

no, the system sees 14.7 as lambda and the wideband if setup still will read 14.7 as lambda, then req fuel should stay 14.7
This is why I would perfer to see lambda used over AFR but anyways

[racingmini_mtl]

Actually, the req fuel should be done with the AFR for the fuel you're using, i.e., 9.x for E85. This is a computation that is completely external to the MegaSquirt so you need to use the real AFR for Lambda = 1.0. For all other AFR values, you need to assume that 14.7 is Lambda = 1.0 since that is what the wideband controllers use as default.

Jean

[Panoles1]

Actually, the req fuel should be done with the AFR for the fuel you're using, i.e., 9.x for E85. This is a computation that is completely external to the MegaSquirt so you need to use the real AFR for Lambda = 1.0. For all other AFR values, you need to assume that 14.7 is Lambda = 1.0 since that is what the wideband controllers use as default.

Jean

That is what I did.. I used 9.5 as my target AFR to achieve the req. fuel...

I have since increased that number to get a req fuel of 6.4, which is way more than enough. The car starts up, idles very rich (expected), drive around the block seemed ok and half way back she's goes extremely lean again. Fuel pressure based on the gauge appears to be reading correctly and changing with load.

[techsalvager]

did you change your wideband to read AFR values based on e85?

[racingmini_mtl]

That is what I did.. I used 9.5 as my target AFR to achieve the req. fuel...

Do you mean that you set AFR to 9.5 in the window where req fuel is computed? And that you did NOT set your AFR target to 9.5 in the AFR target table, right?

Jean

[Panoles1]

That is what I did.. I used 9.5 as my target AFR to achieve the req. fuel...

Do you mean that you set AFR to 9.5 in the window where req fuel is computed? And that you did NOT set your AFR target to 9.5 in the AFR target table, right?

Jean

Yes, that is correct... In the engine constants/Req Fuel, I entered the 9.5 in the AFR target value..

[Panoles1]

did you change your wideband to read AFR values based on e85?

The way i understand it... I shouldn't have to mess with the wideband sensor or gauge, as they are only measuring Lambda and displaying that reading as an AFR for either fuel types. Am I missing or not doing something correct?

[techsalvager]

did you change your wideband to read AFR values based on e85?

The way i understand it... I shouldn't have to mess with the wideband sensor or gauge, as they are only measuring Lambda and displaying that reading as an AFR for either fuel types. Am I missing or not doing something correct?

if you didn't mess with the wideband and change reported AFR to be for e85, then lambda will = 1 at 14.7 AFR still which means you would need 14.7 in req fuel as well.

[Panoles1]

did you change your wideband to read AFR values based on e85?

The way i understand it... I shouldn't have to mess with the wideband sensor or gauge, as they are only measuring Lambda and displaying that reading as an AFR for either fuel types. Am I missing or not doing something correct?

if you didn't mess with the wideband and change reported AFR to be for e85, then lambda will = 1 at 14.7 AFR still which means you would need 14.7 in req fuel as well.

I'm confused then... Where is that I need to make the required change for the additional fuel required?

[racingmini_mtl]

if you didn't mess with the wideband and change reported AFR to be for e85, then lambda will = 1 at 14.7 AFR still which means you would need 14.7 in req fuel as well.

As I mentioned before, that is not correct. Req fuel needs to be computed using the real AFR for the fuel used. Please stop mentioning this incorrect statement.

Jean

[Rick Finsta]

For E85, I run 9.8 on the req_fuel page, and then I have my TE WBO2 set to read Lambda=1=14.7 for simplicity (reads as if it were gasoline). I have both a Lambda gauge and the AFR/AFR target gauges on my gauge panel, so I can monitor both to ensure everything lines up.

To clear it up, the 9.8 on the req_fuel page is what's used for the req_fuel calculation (and at least also for VE table generator calculations in TS_beta), but it does NOT carry over to your AFR gauges. That is, your AFR gauges will still read as gasoline, or Lambda=1=14.7, unless your WBO2 controller can be set to change it to Lambda=1=9.8 for E85, in which point MS will report the "actual" AFR number instead of the "relative to gasoline" number. There are enough tuning tables for E85 out there at this point that it doesn't matter which you use to tune, as long as you know which one you're using!

[rabid]

9.8 is the req_fuel for true 85% content e85. If you know the true percentage you can calculate it. Gasoline% x 14.7 + Alcohol% x 9 = afr number True e85 is 10.0 to 10.8 req_fuel from summer blend to winter blend.