420A SPA Turbo fuel management unit rich idle

[jesse12345]

Hey all so I'm using the SPA Turbo fuel management unit, I think max is 14:1 on it and it works great, I'm running real rich at idle and my fuel pressure at idle is around 29 lbs. Have any of you tried that unit out yet? I know I need to pick up a megasquirt but I'm running low boost for now just trying to enjoy the car. I have a new front and rear o2 sensor on the way, my front one is new already but I'll just snag another new one just to make sure.

 

[BLACK'98DSM]

How rich is it running? Do you know the AFR? Also what kind of injectors and fuel pump are you running?

 

[jesse12345]

I'm running a 340lph fuel pump its on stock injectors and the afrs hit 11-10 at idle it runs pretty smooth so I don't know what the deal is.

 

[BLACK'98DSM]

Internally stock I'm guessing? Also could you drop a link for the specific unit you're talking about? SPA makes a few different ones.

 

[jesse12345]

6AN 10-100 PSI Fuel management unit

SPA TURBO has a large selection of Fuel Management Units for street and race cars ready to ship. Check it out our prices!

spaturbousa.com

That's the link and my engine is fully built

 

[DrewmHolland]

Ik this is an old thread but I’d still like to chime in for someone in the future to read this… the fmu I got from spa turbo would only let me drop my base pressure to about 30psi, what I discovered is that you need to take it apart and sand down the plunger until you’re happy with it. Basically it gets rid of a lot of spring pre load and now I’m able to go all the way down to 5psi

 

[DrewmHolland]

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