WAY too rich, still
 

got my diy setup running but i am having a drivablity problem. my set up is, 13g turbo off of a auto DSM, i think the wastegate is at 9psi(and thats as far as i noticed it went on the guage). first gen probe intercooler, VTA BOV with a ton of spacers so it stays closed at idle. and 310cc injectors from a 89 probe gt. and a cartec FMU.

the problem is that the car is really rich. idles around 12.5-13:1 but as soon as you hit the gas at all or try and drive around the block it basically stays pegged out at 10:1 on the guage (AEM ugeo wideband) car bogs and stutters pretty bad. timing is set to 6 btdc.

i have searched and havent turned up anything too usefull. i am going to try and adjust the afm, but i have read the screw is just for idle, and some people have adjust the spring inside the afm, but say thats also just for idle. so which is it?

and also i set the FMU by just turning on the fuel pump, engine not on. i have a adjustable fuel regulator with a guage it put in the feed line before the fuel rail with just the adjuster screwed all the way out so i just had the guage to read. i set it to 55psi with no vac on it, did i set the fmu right?

any help would be great :bigtu:

there should be two adjustment screws on the FMU. one in the middle with an allen wrench, which 55psi is fine. anywhere between 48-55psi is good at no vaccum.

however, there should also be a needle vavle that allows for the rate of gain to change. sounds like you're at full 12:1 ratio. I betcha the fuel pressure is maxing out at 120psi, you probably only need like 70-80.

dont adjust your oem afm tension, it's best as is. however DO adjust the idle screw to idle at 14.7, it's under a little cap you have to drill out.

i have the bleeder valve turned out some right now. but its pegged out rich, even when it isnt under boost. i also might try and adjust the pressure on the FMU again, but while the engine is running this time. also, i have the check valve for the fmu in the vac line going to it, or does it have to be after the bleeder valve?

just idle to car. make sure you have 35psi at idle. pull the vacuum line on the OEM FPR. kink the line so it doesnt foul the idle. turn the preload to hit 48-55psi. put the vacuum line back.

adjust the AFM to idle at 14.7. theres a little cylinder with a silver cap, you must drill the cap off and exposed a screw. turn it back about 1 full turn counter-clockwise. that shoudl get you to 14.7.

go driving in boost, continue to back the needle vavle more open and open untill 12:1


vacuum line goes straight into FMU. check valve on needle vavle, postitioned to prevent vacuum from pulling through the unit, boost should escape out.

i will do all of that tomorow. so the guage in the feed line BEFORE the fuel rail is right?

yes

re-set the fmu with a new guage, and the bleeder is turn about 2/3 out, check valve after the bleeder to let boost out but no to pull vac. adjusted the idle on the AFM, so thats a little better. did about 1 1/2 turns out. but as soon as i hit the gas, pegs out rich. did a WOT 3rd gear run. turbo spools, holds 9psi, stays pegged rich on the guage. but the car just doesnt pull at all. i will try to turn out the bleeder more, but there i just not much more i can turn it out. i am starting to think these 310cc injectors are just too much for the stock ecu.

I don't understand why you people keep "tuning" your FMU with a fuel pressure gauge. who gives a fuck what the fuel pressure is if the a/f is way off? tune that bitch with your wideband, throw the stupid pressure gauge away. how hard could this be? you're rich. back down fuel pressure. the end.

if you turn the bleeder valve all the way out and it's still pig rich, you need a restrictor on the vacuum line.


Ben, you at least need to correctly set the preload, after that the pressures are trival :gay:

i am not tunning by a pressure guage, i have a AEM wideband. i have no fuel pressure guage on the car, only had one to set the base pressure on the fmu. i will bump upmy timing to 8btdc also to see if that will help it out some

alright screw this im putting the stock injectors back in. even at cruise with like 10in of vac, the afr is 10.2:1 and with the bleeder screw all the way out, the leanest it ever got was 10.3:1

the fmu will not effect the fueling in cruise.

i was seeing a soild 14.7 cruise with 305cc injectors with the stock ecu and afm.

Why? I didn't. Twice with 2 different FMU's.
I'm wondering if he doesn't have the center screw jacked down waaayyy too far. That would make cruise too rich.

also the needle valve only affects the rising rate, not the overall pressure. overall is adjusted with the center screw.

so you at least know your not overriding the oem fpr by jacking up the pressures out of boost.

otherwise im all for the "watch your gauge" method.

i am begining to hate this turbo project, put in the stock injectors and now it wont idle at all. WTF!?!?! time to re-check everything.....again.

looks like some of the pintle caps and the big spacer/o-ring on the stock injectors were cracked. i will try and swap them out with the ones on the 310s and try again

put the 310s back in. i can get it to idle 13-15:1 so thats not an issue. set the fmu again. base pressure is 48ish psi. kept the guage on and set it under the windsheild wiper and went for a drive. doesnt add any fuel in vac, starts adding in boost. at a full 9psi of boost, its at 65-70 psi of fuel pressure. idle afr is ok, but as soon as you start driving, stays at about 10-10.5:1 afr. looks like i need to adjust the tension spring now?

went 4 clicks tighter on the AFM, little to no improvement

1> is the fuckin thing hooked up right? get the fuel lines crossed?
2> do you have an o2 sensor? does it work? probe it with a dmm

1-yep, fmu actually says in and out on the bottom of it. and i veryifed its working correctly

2-yes and yes. it is plugged in but its not in the downpipe, just hanging there while my wideband is in. i know it should make it a tad richer, but not as much as it is. the car has NO CEL on.

:gtfo:
Dude, here's your hat. Now sit in the corner.

BTW, you didn't feel that that was critical information you should have included in the very first post?

:rofl::rofl::rofl::rofl::rofl::rofl::rofl::rofl:

the o2 is ignored at WOT, so its doesnt matter

I agree with you; o2 feedback is ignored at full throttle. However your problem is that you're cruising too rich. Because you're not running an o2 sensor. Because it's dangling in fresh air.

http://search.aol.com/aol/redir?src=...=Image Details

and again, its too rich when the boost is in. i can deal with cruise later, the main problem right now is the 10:1 afr under boost

I disagree with that statement. Main problem is you're telling the ECU to fuck off by sending it completely wrong readings in closed loop. You're throwing it so much fuel in closed loop that it would take more than a blip of WOT to clear it out...who knows, you might even be blowing out spark it is so rich. And you know what? You can (and should) be boosting while not WOT.

Deal with known problems before trying to diagnose other, related issues.

alright then guys, can i leave the corner long enough to weld in another 02 bung in my downpipe? i was doing some 1st through 3rd gear runs and was just pegged rich the whole time

I think your main problem right now is cylinder wash.
After that, your plugs and wb sensor are getting crudded up.

Tuning the FMU is really pretty easy. I continue to encourage you to ignore the (inpercise and fairly irrelevant) fuel pressure gauge and tune by (highly accurate and extremely relevant) wideband only... But I guess I like to talk to walls.

I might know a thing or two about tuning an FMU, so you may want to listen :dunno:
http://img113.imageshack.us/img113/7...odifiedan9.jpg
That was with a BEGi FMU, 190lph hp, 1.8 injectors, and 9-10 psi

Please do.

i have returned back to my corner, but heres an update

i havent been tuning by fuel pressure at all, the only time i even looked at the guage was to make sure it wasnt adding fuel in vac and adding too much in boost.

well i put in the other o2, i set the afm back to the stock tension (i actually marked it) cruise is about 12.5-13:1 now. still about 10.5:1 under full boost pulls. feels a tad stronger now, pulled up to 85 decent. and i have the check valve in the line going from the intake to the FMU to act as a restector.

Hold up. You didn't hook the check valve in so that the FMU sees boost, but never sees vacuum, did you? As in, you're not trapping a boost signal in the FMU, are you?

it is hooked up the not pull vac, but to let the boost out. the FMU is working like it is supposed to, already veryifed it with a fuel pressure guage during a drive. remeber i have the cartech/begi with the bleeder valve. so i dont see how the fmu can "trap" boost. it drops back to base pressure when in vac and rises in boost

but, my dumbass didnt put lock washers on the turbo hardware, so i have to make a trip to home depot tomorow anyway.

What WBo2 are you running? you shouldn't be so rich.

AEM ugeo.

the bleeder valve only sets an upper limit on the boost that the FMU sees. If you had had the check valve in so that it saw boost but not vac, then the fmu would raise fuel pressure the first time it saw boost, but wouldn't return to normal during engine vacuum conditions, thus "trapping" boost

I don't think it would trap boost since the needle valve vents to atmo. I think it would trap to atmo pressure though.

How's the UEGO sensor looking? Is it coated black? I know those NGK sensors don't get calibrated like the Bosch sensors do, but I do seem to recall reading something about an AEM UEGO calibration procedure somewhere. I'd look into that if I were you.

Sam & Scott both ran 305 cc/min injectors off their stock ecu's without incident. Granted, Sam's car has sequential injection, but Scott's car doesn't.

Perhaps. You've used an FMU, and I haven't.

the sensor is pretty damn black now. i could try and spray some electronics cleaner on it, but it is responding. i have had the check valve pre-fmu and post bleeder, the fmu worked the same both times.

ok guys made some progress today. put a TINY restictor in the vac line going to the fmu. its actually a tad smaller than a wd-40 straw. i glued it inside a inline connector and it seems to have helped. idle is about stoich, 40-50mph cruise is still on the rich side, but not horible. managed to get boost leaned out with that restrictor. starts about 12.5, then 4500rpm or so hits about 11.5 and about 5500-6000rpm till redline hits 10-10.5. that looks like about the best im going to do with a FMU. looks like the restrictor was the biggest thing i was missing. the hole the air passes through is now about the width of a straight pin. and i managed to put a hurting on aredneck in a 3rd gen T/A, thats always a good thing. the car feels about as strong as it was on the 75shot of zex on the butt dyno.

Perhaps try a dual check valve setup on the bleeder valve. Ben had great luck evening out the high-rpm fueling with it. May want to run a quick search and see what he did.

also sounds like you need to back off the overall pressure some more. turn the center screw out. you should cruise at stoich.

its all ready set at 48 psi. should i set the fmu to about 36psi or so? like the stock fpr is at full vac? im glad i didnt take off the fuel guage yet, i think i will actually do that tomorow.

fuck the fuel gauge. I've said that before, right? They're known to be inaccurate. back down the center screw and watch your wideband.

will do that tomorow then

the center screw is almost all the way out, still at 13ish cruise. running fairly decent now . still gets really rich up top. i will try the duel check valve and see it if helps

no it won't help your cruise
did you f-up your afm flapper position? if everyone else can cruise with those injectors, you can too.

nope, its at the stock postion. i marked it before i touched it before

maybe you'll need to adjust the arm to the lean side. wierd :dunno:
they're high z injectors right?
you verified the o2 sensor is working?

another member also had an odd issue like yours. his ecu just stopped going closed loop. his problem was fixed when he replaced the ecu.

i could try and move it a couple clicks and see if it helps. and the injectors are from a 89 probe GT. i might get a new regualr 02 sensor, those are cheap. but the wideband it reading fine.

buy a fucking megasquirt

:inout:

lawl...don't you know how to solder them up bryan?

takes less than an hour.

actually had one on my probe. i dont want to go into all of that again. i just wanted a simple, no frills setup on the miata.

305cc injectors, RRFPR, check valves, Walbro 190HP, Bipes, O2 clamps, and you still can't tune it perfectly

vs.

460cc injectors and an MSPNP

Who's got more shit bolted to their car?

oh shnap.

I would check the NB o2 sensor with a volt meeter, you might learn that the thing is shot, or that your WB is inaccurate, or nothing at all.

i have no bipes and o2 clamp. just a fmu and 310cc. so by going to a standalone, i would just lose the fmu. if i wanted to go standalone, i would have done it, but i dont.

and i will just throw in a new narrowband in this weekend.

put in a new narrow band, no difference. i have 100miles on this tank of gas and i only have 1/4 tank left. i think i will just put the stock injectors back in

I don't know if i am correct... But how do you think the ecu is handeling injectors that are 50% larger than stock?? Normally very rich...

So you need to lower your base pressure below oem levels...

The only way i could think of is to make a bypass between the fuel suply and the fuel line between the afpr and the fuel rail. In the bypass you add a adjustable restrictor so you can adjust your static FP below stock levels.(tune that on your wideband)

At boost the afpr takes care of the rest...

they are only 30% larger and it can be done. I did it for over a year and made 240 miles a tank, consistantly.

something else is going on. you should be able to lean it out enough with just the idle mixture screw on the afm and it should be golden.