Leaning out
05-07-2017, 08:17 PM
#21
Newb
Thread Starter
Join Date: May 2017
Posts: 21
Total Cats: 0
There aren't any puddles, and I keep an eye on the afr gauge all the time. It never leans out with no boost pressure. Before I put the turbo on, it would richen up to about 12.8 at WOT. I've told you pretty much all I've done to the car. what else do you need to know?
Reply
0
0
05-07-2017, 08:21 PM
#22
Let's start with how you converted to a return style system, I assume you removed the in tank regulator? How exactly did you plumb the FMU? How are you monitoring fuel pressure? Any way to tape said fuel pressure guage to the windshield so you can watch FP as you make a pull?
Reply
0
0
05-07-2017, 08:28 PM
#23
Newb
Thread Starter
Join Date: May 2017
Posts: 21
Total Cats: 0
I used this link https://www.miataturbo.net/diy-turbo...l-style-74629/ . Yes, the in tank regulator was removed. So here's how my fuel system is plumbed: fuel tank, fuel pump, fuel filter, rail, isr fuel rail adapter, afpr, fmu, back to the tank. The only way I can see the fuel pressure is on the afpr. And it's pointed towards the front of the car.
Reply
0
0
05-07-2017, 09:42 PM
#27
So you've verified that things are working in the right direction.
Looking at this link Vortech Fuel Management Units | JEGS
You'll see there are different rising rate settings. Again with the lack of data you've provided I'm assuming that was 5 psi of boost and you saw 10 PSI rise so that would be 2 to 1 and that isn't one of the options. you need to keep cranking up the fuel pressure till you're not lean. If u come back and say you have it setup for 5 to 1 then your fuel pump isn't keeping up . This is assuming you understand that fuel pressure is less than the set point under vaccum, equal to set point at 100kpa and rises at the FMU rate in boost. What actual pressures are you seeing.
Looking at this link Vortech Fuel Management Units | JEGS
You'll see there are different rising rate settings. Again with the lack of data you've provided I'm assuming that was 5 psi of boost and you saw 10 PSI rise so that would be 2 to 1 and that isn't one of the options. you need to keep cranking up the fuel pressure till you're not lean. If u come back and say you have it setup for 5 to 1 then your fuel pump isn't keeping up . This is assuming you understand that fuel pressure is less than the set point under vaccum, equal to set point at 100kpa and rises at the FMU rate in boost. What actual pressures are you seeing.
Reply
0
0
05-07-2017, 09:59 PM
#28
Newb
Thread Starter
Join Date: May 2017
Posts: 21
Total Cats: 0
I have an 8:1 disk. I plan to cut a12:1 (2.72") disk tomorrow at work to see if that changes anything... and honestly i didn't watch the boost gauge. As soon as I saw the afr at 16 I stopped. It didn't feel like there was any boost at all though. I didn't rev past 4K
if I crank up the fuel pressure it will only get me to 75ish psi. I think it would still be running lean but I can go try it
with the video I took it was hard to tell... all I can tell is that it's at 60psi at idle and got to about 70psi when I tried to get on it.
if I crank up the fuel pressure it will only get me to 75ish psi. I think it would still be running lean but I can go try it
with the video I took it was hard to tell... all I can tell is that it's at 60psi at idle and got to about 70psi when I tried to get on it.
Reply
0
0
05-07-2017, 10:45 PM
#30
At this point you're lean with 60 to 70 psi something is wrong and honestly there is no good way to trouble shoot it with a FMU. You're left to guessing and checking and doing rediculouse things to try to log data. This is why you got a bunch of snarky smart *** responses when you started this thread. It's expected that you take the advise of those with a high post count or their names in green. I also understand that simply accepting the "because I said so" reasoning behind the short answers is tough to swallow. I'm pissing off the old guard by spoon feeding you but it was obvious your weren't going to figure it out yourself.
Just so you're aware the correct way to deal with this is to wire in a pressure transducer into the fuel system and log it through your megasquirt. This is what I did, I discovered an issue with my fuel pump and corrected it in literally one log and a single click on Amazon for a new fuel pump.
At some point you have to ask yourself, what's my time worth?
Just so you're aware the correct way to deal with this is to wire in a pressure transducer into the fuel system and log it through your megasquirt. This is what I did, I discovered an issue with my fuel pump and corrected it in literally one log and a single click on Amazon for a new fuel pump.
At some point you have to ask yourself, what's my time worth?
Last edited by Bronson M; 05-08-2017 at 06:14 AM.
Reply
0
0
05-07-2017, 11:03 PM
#32
Welcome back, @Schuyler! Seeing you post again is the redemption of this thread.
I may be reaching out to you regarding some MS stuff in the coming weeks.
Reply
0
0
05-08-2017, 11:13 AM
#33
Retired Mech Design Engr
iTrader: (3)
Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,009
Total Cats: 856
Thanks David! I am in China this week, but work is slowing down some. I've been spending ~1 week a month at my house lately. Hopefully going to start putting some time in to the car here soon and begin posting once again in my own build thread. I'll post my to-do list once I'm back state-side. I have a track day scheduled in July, as well as a travel freeze for that month. So, I'm running out of excuses to not get working on the car.
I may be reaching out to you regarding some MS stuff in the coming weeks.
I may be reaching out to you regarding some MS stuff in the coming weeks.
Reply
0
0
