a restrictor should not play a large role, but it could be an issue at high boost but not so much in vacuum. if you're having issues with immediate fuel delivery it is usually a fuel volume issue.

 

sounds like the classic microtech staging. but going lean with 1000cc primary is odd have you played with the stage %

 

50% it doesn't happen if I ease into throttle

 

I'm going to do a static fuel pressure test today with the vacuum hose off the fpr blocked, I'll watch the pressure gauge for fuel on the fpr and see if it drops immediately as the throttle is hit.

Either the fpr is culprit or the fuel pump (or both) Base pressure is 40 psi, I wouldn't think that's too low for good fuel volume with 1000cc injectors on a walbro 255 hooked up with 10g wire.

 

static pressure can be very misleading for overall volume, if the pressure drops at all while stabbing the throttle then you have a major volume issue.

 

I'm going to do the test with the vacuum hose off the fpr to see if the static pressure drops.

My fpr is an aem adjustable.

 

Static fuel pressure seems fine , the problem is mostly occurring when I hit around 0hg with quick throttle transition.

Could it be my map source ? It's currently right after the throttle body

 

-5" of vacuum is how the micro is set up as one of its 2 parameters for staging. lower it a bit and see if it shifts where it leans out. what inj you running? 50% indicates you have 4 of the same size

 

1000cc x4, I have staging at -5 hg but I have map setup for it.

I did the the static pressure test and fuel pressure is absolutely solid.

I went ahead and tested in gear on my Jackstands up to 55mph in 3rd gear and it runs good, really rich though.

I think my next step will be road tuning after I get all the little things fixed and have it safe for a ride on the road.

 

it could be your injector lag, honestly i never messed with it in the microtech and leave the default settings but if you reset it all then that could be an issue.

 

It only works in crank degrees. Should be all stock I never touched the settings

 

no matter how I adjust my settings I'm having the huge lean spike on big throttle changes when i hit the throttle fast, im wondering if something is up with my timing or what the deal is, ive checked everything over, im lost as to why it would just spike lean no matter how much fuel i throw at it.

I'll make sure my spark plug wires are all on correctly, it's just not adding up, theres no reason for it to go lean like that.

 

does pump1 show in the info window when you stab the throttle?

 

Yeah it shows. I think I may have to go and troubleshoot everything to rule it out.

Nothing is making sense, I'm thinking maybe a huge vacuum leak/surge when I hit the gas is happening.

 

this isn't a AFM based system, that would not cause your issue.

 

well what would cause my issue ? I am using an FD UIM and throttle body, with the secondary butterflies removed.

It seems like there is just wayyy to much air coming in, or something isnt right. I've tried adding fuel all over the place and nothing seems to change, really starting to get annoyed at this point, don't know what to do.

The car afr will go very lean with small throttle changes at low rpm ive seen it goto around 17+ at 1000-2000 rpm, I've added tons of fuel to pump settings, changed the fuel curve and nothing.

Something isn't right and I'm pretty much lost at this point, soon as I can log things better I hope to further address the problem. I may start doing diagnostics/troubleshooting to make sure everything is as it should be, because nothing makes any sense.

Why wouldn't a huge surge in vacuum cause an issue even though its not an afm system ? It seems like something is just overloaded, or not set correctly or running right.

17.0 afr from a small throttle step shouldn't be happening at low rpm, the problem seems to go away as rpms go up and is most prevalent from the transition of low rpm to mid.

Im wondering if my injectors are maybe not flowing properly also, they are brand new injector dynamics, but i just dont get why i need so much fuel at low end.

My idle values are around 1.5 - 1.7 when in vacuum at idle around 1000 rpm, doesnt that seem high for id1000s on a stock port with 50% injector staging ? or is it just me

 

it's idling at 900, so there isn't too much air coming in. there is a huge surge of vacuum, when you apply the throttle. a large leak would show up as very low or no vacuum.

your issue could be low voltage to the injectors, air pressurizing the fuel system instead of fuel, bad grounding or something else.

funny, we just went through a similar situation like this with djsl on the 2nd gen forum section and it wound up being a faulty fuse and injector clip.

 

When I hit the throttle hard it can go up to 0hg in a split second, is that normal ?

My friend is working on helping me get some logging done.

I've checked the injectors before in test mode and they all pulse. I've even checked voltage on them and they measure battery voltage with key on.

 

perfectly normal

i did have one car where the lines through the FPR were backwards and the car would even run, but it had the exact symptoms you describe.

 

I hooked up the fpr just like they say to hook up in the instructions.

2 lines on the sides are coming off the return from the rails going to it and the bottom one goes to the return to the tank.

Was thinking of raising base fuel pressure to see if that does anything, from 40 to maybe 45 psi or more

 

You can kind of see how it's hooked up here.

 

if you steadily feed the throttle in does it fatten up with increased ms values? apart from the throttle blips is afr respond to fuel changes. eg at 2000 rpm does incresing ms show up on afr gauge. Sorry I havnt been following fully so may have missed if you have stated this or not

 

It's definitely fat, it's just the starting point at low rpm sucks. I'm going to bring up my fuel pressure see if it helps any.

I'll soon be logging with wideband afrs so I can see my inj ms values while the lean spike occurs.

 

did you pay for the wideband unlock on the microtech? .or you logging through something else. stupid microtech having that as a paid unlock.

 

Logging through software my friend wrote himself with visual basic lol