PROBLEMS: running too rich

[HS13KLS]

i have a 91 240
KA24de
walbro 255
z32 fuel filter
stock injectors
apexi safc2
innovate wideband
3in intake

my car is just getting ready for a turbo (an sr, so thats why i have the safc2, and the 255)

it used to run just fine until a few days ago.
when i wired in my safc2, i did it quick and never had a problem with it/with the innovate wideband also.
but my only problem now is, all of a sudden its running really rich

i tuned my car to run around 14.3-15.4 ish in town under 50% throttle
and one day i was driving down the road, it spiked up to 18.3-20.2, and it was leaning out.
so i turned my car off in traffic, and just re did the safc and zeroed it out.
then my car started to run rediculously rich. at 8.2-10
so i tuned it down to where i had it at idle. still was the same. after i maxed out the safc2 at -50 it would idle around 12.2 (keep in mind it USED to run at 14.3ish)

anyways now it just runs shitty, and super rich, i re did ALL the wires for the safc and wideband and head shrunk everything. still nothing. i dont get it.
anyone have a suggestion?

[neilsan]

"hurr i installed a afc and now my car runs like crap"

why do people assume they need an afc anyway? if you want to learn how to tune you'd better understand the effect that messing with maf voltage has on ignition timing maps.

get rid of that ricer chic' piece of shit pseudo tuning tool and just get a rom tune for anything that you actually need tuning for (big injectors, z32 maf).

[UNISA JECS]

Yea the 255 fuel pump bumped up your fuel pressure, usually about 6psi+ in most cases, this will makes yoru fuel injectors larger than what they really are by the square root old vs new fuel pressure.

Sounds like your wideband has fouled out by running to rich, I use teh Innovate LM-2 so im not talking out my ass....in overly rich running the wideband will output some crazy lean numbers when in fact you are really running to rich.

You need to get a fuel pressure gauge and adjustable fuel pressure reg. if you want to get your car running back to normal again.

Sounds like your wideband is funny now, I suggest trying to recalibrate it, if that still doesn;t work you can try cleaning it with propane torch nicely and evenly moving it around, dotn concentrate in one area.

[HS13KLS]

"hurr i installed a afc and now my car runs like crap"

why do people assume they need an afc anyway? if you want to learn how to tune you'd better understand the effect that messing with maf voltage has on ignition timing maps.

get rid of that ricer chic' piece of shit pseudo tuning tool and just get a rom tune for anything that you actually need tuning for (big injectors, z32 maf).

if you didnt read my post. iam getting an sr. so i had it in advance. and it was taking of closet space. so i figured id use it. and btw i do have a z32 maf...but just not on right now.. i dont see the point in running it right now

Yea the 255 fuel pump bumped up your fuel pressure, usually about 6psi+ in most cases, this will makes yoru fuel injectors larger than what they really are by the square root old vs new fuel pressure.

Sounds like your wideband has fouled out by running to rich, I use teh Innovate LM-2 so im not talking out my ass....in overly rich running the wideband will output some crazy lean numbers when in fact you are really running to rich.

You need to get a fuel pressure gauge and adjustable fuel pressure reg. if you want to get your car running back to normal again.

Sounds like your wideband is funny now, I suggest trying to recalibrate it, if that still doesn;t work you can try cleaning it with propane torch nicely and evenly moving it around, dotn concentrate in one area.

i have a LC-1
i forgot to mention i re calibrated it. and it seems to be working fine. as for the 255 pump..that, the z32 fuel filter, afc have been on my car for MONTHS..probably since april ish. so its not like i JUST put these thigns on my car, and now it runs like shit. these are parts that have been on for a while. and all of a sudden it happened.
and when i said it was running lean like it hit that crazy 18-20 that was only for about 3 actual seconds..a lot longer than just me shifting and noticing it though. it was running at that.
as for the fpr, and guage. my buddy has one on his gsr, and he also put a 255 on his car. and it ran pretty rich after he did. he said his bumped up about 10 pounds.

i mean i dont know what else to do. my spark plugs are almost fouled out..pretty black from probably running so rich.. but im trying to think of anything else it could possibly be.., its not like it runs terrible..it just runs REALLY REALLY rich..

[neilsan]

Square root old vs new fuel pressure? what?

Installing a walbro pump with no other modifications to the fuel delivery system will not increase the fuel pressure. At a celing of say 60psi, a walbro can still maintain 255lph, but that doesn't mean it increases the fuel pressure to a figure over that which is set by the stock regulator. at all.

OP- I did read your original post. I know you bought it for your SR. There is no reason to. You should just find a stock SR MAF instead of using an AFC to gimp a Z32 MAF install. Get rid of your AFC, or else your SR will run like shit too.

[HS13KLS]

Square root old vs new fuel pressure? what?

Installing a walbro pump with no other modifications to the fuel delivery system will not increase the fuel pressure. At a celing of say 60psi, a walbro can still maintain 255lph, but that doesn't mean it increases the fuel pressure to a figure over that which is set by the stock regulator. at all.

OP- I did read your original post. I know you bought it for your SR. There is no reason to. You should just find a stock SR MAF instead of using an AFC to gimp a Z32 MAF install. Get rid of your AFC, or else your SR will run like shit too.

well when i have the money i will invest in an AEM. and get a map.
but right now. i dont.lol

or i can run a mega squirt that i have...i just need to wire it up. but then i need to get a ford edis off of a junkyard car.

anyways. but i dont think you get what i am saying

it happened a few days ago.
(when i originally wired it up. i never put back on that kick panel. so my wiree/ecu were exposed.) i told passengers to watch out and NOT kick my ecu

well im sure eventually my girlfriend mustve kicked it. and i thought she may have messed up some of the wiring. but i re did everything. but still nothing.

basically my car has been running REALLY WELL since before a few days ago..so its not like anything i have put on my car has ruined it. somthing happend..i am trying to troubleshoot

[neilsan]

anyways. but i dont think you get what i am saying


I don't think you get what I'M saying. The AFC is obviously the cause of the problem, so remove the cause of the problem! Whether or not some wires got kicked is totally moot because an AFC doesn't do any good even when installed right.

Ignition timing is determined by engine load. Engine load is calculated with MAF and TPS voltages plotted against RPM. Therefore if you mess with MAF voltages you fuck with ignition timing and that's significantly more important than trying to richen the A/F mixture for a fraction of HP. It's also the WRONG way to "trick" your ECU into running a Z32 MAF. I didn't say get AEM standalone management, I said get an SR20DET MAF.

You probably spent like $300 on the AFC and are probably butthurt about hearing they're worthless and don't want to get rid of it cuz of the money you spent. I really understand. I'm sorry you bought into the marketing but you have to understand that you're really, really better off without it. You can probably sell it for at least $280.

[UNISA JECS]

Square root old vs new fuel pressure? what?

Installing a walbro pump with no other modifications to the fuel delivery system will not increase the fuel pressure. At a celing of say 60psi, a walbro can still maintain 255lph, but that doesn't mean it increases the fuel pressure to a figure over that which is set by the stock regulator. at all.

OP- I did read your original post. I know you bought it for your SR. There is no reason to. You should just find a stock SR MAF instead of using an AFC to gimp a Z32 MAF install. Get rid of your AFC, or else your SR will run like shit too.

A walbro 255, Z32 TT, Q45 fuel pump installed on a S13/S14 will bump up the fuel pressure only becasue the stock FPR wasn;t designed to bleed of twice the amount of fuel it see's with these pumps.

The Z32 and Q45 have a mechanism to control the over running of teh stock FPR, its called a FPCM fuel pressure control module and it restricts the voltage to the fuel pump down to like 8 volts which greatly reduces the amount of volume teh fuel pump pushes during idle and cruise. I have first hand experience on more than 15 cars with any combination of the pumps I described and used a fuel pressure gauge to read the pressure and a volt meter to see teh affect voltage has on fuel pump output.

[UNISA JECS]

Here is the formula:

The square root of x multiplied by z divided by the square root of y = new injector flow rate

Where:
X = new fuel pressure
Y = original fuel pressure
Z = lbs per hour

First, find the square root of the new and original fuel pressure.
New fuel pressure: square root of 55 = 7.416
Original fuel pressure: square root of 43.5 = 6.595

Then divide the new fuel pressure square root sum by the original.
7.416 / 6.595 = 1.124

Then multiply this total by the size of the injector. In this case we are using the stock Saturn 19lb injectors.
1.124 * 19 = 21.35

At 55psi the injector now flows 21.35lbs/hr

[neilsan]

I believe you but I also know a couple ppl (myself included for a few months before my swap) with stock KA's and walbro pumps and their cars don't run shit rich as the OP is describing, maybe they're just lucky..

I have a hydraulic pressure gauge and when I hooked it up after getting my swap running the fuel pressure was proper @ 43psi iirc. If an sr is supposed to suffer the same problem with a walbro then i guess i'm one of the lucky ones too?

[UNISA JECS]

I believe you to, because some of the cars I've done onny were recieving ~10.5 to low 11v at the fuel pump and those cars did not overrun the the stock fuel pressure regulator but the cars that saw high 12-14v did over run the stock FPR some by as high as 10psi.

[HS13KLS]

so all in all

its the safc.
its that i dont have a fpr/guage?

is that what you guys think?

[HS13KLS]

i found out my problem, it was my distributor ROTOR. it was really damaged..on a 91 dohc, when you look at the rotor, the metal conductor part is supposed to be a perfect circle, but mine was a 1/4th moon shape.

so i fixed it, and now its fine.

[neilsan]

Well whaddya know.

I'd be lying if I said I didn't feel a vague sense of remorse for giving you shit about the SAFC but the fact that they're bogus tuning tools and not even necessary for an sr swap really is pretty indisputable.

i might get flack for this but if you dont want to look for a stock sr maf, you can send your ecu to EMance to get a daughterboard installed tuned for the Z32. if you sell the AFC it'll more than pay for that service.