Sfmu? Trouble?

[Walkin' Bear]

Ok so just had my vortech sfmu installed. It took the place of my summit 12:1 regulator. Car is boosted to 8psi nothing major but needed the sfmu. Car idled fine before sfmu. After sfmu and lc-1 wideband installed car sounds great both items work. However after a few seconds of running 14.5 to 14.7 the wideband shows that it will go to 12ish:1 you hear the motor suddenly change pitch and than it goes back to 14.5-14.7.... Why is it doing this please someone help me. It does the bump in fuel bout every 5 seconds and only last maybe a moment just enough to catch it on the wide band and the motor to feel it and than back to normal. Please if you have any thoughts let me hear them or text me or call me or pm I'm really not sure what this can be so any help is helpful.
Thanks yall.

 

[Josh97eclipse]

do you have the bleed screw in all the way along with the other screw which is boost? what Injectors are you running? I have a sfmu running 450s and my idle psi is 10 but i needs to go up more because im idling at 15.5, when the car first starts its pig rich.

 

[Walkin' Bear]

I had 36lb(378cc) but the guy that is tunning it said they were to large. He got me a set of stock ones so I guess what 200cc now. Also as soon as I hit boost the car is leaning it way out no matter what is done to the sfmu. What is going on that I don't know about.

 

[Walkin' Bear]

Folks please some help would be really nice any input at all to what can cause car to run at 14.7 after a few moments richen to 12s than level right back out... Also what should be a good starting point in determining what sfmu disk I should use.

 

[96TurboGS]

What is the idle fuel pressure? What disk/shim and spring combo do you have?

There should be two springs and three to four different disks you can use. (Depending on the injectors)

If you are using stock fuel injectors then you shouldn’t be seeing a rich AFR once engine is at operating temp. If the car idled fine before the SFMU with stock injectors in, then you have the wrong idle fuel pressure. (Should be adjusted to 47-50 psi)

 

[Walkin' Bear]

Well I did have larger injectors. I had 36lb injectors. Installed sfmu an no matter what combo of springs an disk that were used could not get the car leaner than 9:1 even at 5lbs static pressure. But before the sfmu was installed I had a summit regulator set at 68lbs and it idled fine. But from what I'm reading that seems like I had that set way to high but still could not have wot due to leaning out hence the reason I opted for the sfmu.

 

[Gruff511]

My buddy with a SFMU and dsm 450cc says he needs an SAFC to control the injectors specifically at idle to tune in the idle right. Do you just have the stock ecu controlling the injectors still?

 

[Josh97eclipse]

I have a sfmu and 450s and i need no safc. your stock injectors are your problem. When I tried the sfmu and stock inj. i leaned out.