req_fuel question

[TraviZ]

does manually raising the req_fuel number raise the overall fuel or remove fuel overall? The numbers I punched in gave me a req_fuel of 10.2 but I was having issues with the engine firing up and dieing within seconds, but once I mannually raised the number it kept getting better, and at a req_fuel of 35, the engine would idle on its own. so am I removing or adding fuel?

[insanezane]

adding it but 35 seems high you might check your injector open time and pwm and also ase wue and ve tables zane

[TraviZ]

i run high impedence injectors so its kind of static to where its set, is there any side effects to having a high req_fuel number? should i lower it down and increase warm up enrichment?

[insanezane]

the high required fuel shouldn't hurt anything unless you runout of fuel on the top end or under load but if the injectors are big enough and the ve table is set to make up the difference it should be fine just check the duty cycle under load usually 80 is a safe limit

[severnrc]

Is it normal for the REQ_FUEL calculator in MS to be WAY OFF? It calculates 9.3 for me, but for my VE table to look 'normal' I ned a REQ_FUEL of approx. 17!

[TraviZ]

what do you consider to be normal? my VE tables starts down in the mid 20's and gets up to 160ish (supercharged)

[Matt Cramer]

Think of req_fuel as your base pulse width. Usually the calculator will land you in the ballpark if your information on the injector size is correct, but some engines can be a bit weird.

[TraviZ]

i have no doubt my engine would be in that weird category, big cubic inch big injector big cam and big blower.