supercharged to rich with STOCK INJECTORS

[t76stang1Day]

ok i just got my car running a couple weeks ago. my motor is stock with a powerdyne w/ a 2.93" pulley. i had 42lb injectors in there w/ a PRO M maf. my wideband was reading 10.8 at idle. which was kind of expected with the 42s on a stock motor. so i had the fmu laying around from the kit, so i threw that in there and pulled out the 42's and put the stock 19's in with the stock maf, and still the same thing, my wideband is reading 10.8ish at idle!!!! im confused can someone fill me in??

 

[clement]

is the FMU working? is the o2 on the wideband dead?

 

[t76stang1Day]

The wideband setup is bran new, got it for the setup. im pretty sure the fmu is working. i also didnt mention that my fuel pressure is now reading almost 100psi..with the 42s it was at about 35psi.

 

[clement]

also didnt mention that my fuel pressure is now reading almost 100psi.

there is a handy little piece of information. you probably have the fuel lines from the FMU to the return hooked up backwards. switch them at the bottom of the FMU and it should work correctly. 100psi of fp at idle might cause it to run a little rich.

 

[t76stang1Day]

pretty sure therre was only one way to hook it up. theres only one set of connections that are the right size for the fmu to hook up to.

 

[clement]

there is only one way to hook them up at the rail. where the fmu lines attach to the FMU they are the same. at the bottom at the fmu they are hooked up backwards, not at the rail and fuel line.

 

[t76stang1Day]

there is only one way to hook them up at the rail. where the fmu lines attach to the FMU they are the same. at the bottom at the fmu they are hooked up backwards, not at the rail and fuel line.

thanks man u were right. i wasnt thinking under the fmu, because i assumed they were right. i swapped them around and my fuel pressure is now at about 60psi at idle, and the a/f is a little leaner. a/f bounces back and fourth between 12 and 14ish at idle now. so il try and bump fp down now to make it more optimal at idle. il tell u tho its idling crappy. it goes up and down and tries not to stall. wen i first started my car with the 42's and pro m, it was the first time i started the car in 6 months, also had a dead battery for all that time. it was idling alittle high for that first startup. but after idling for about 10min till i got heat in the car the idle dropped back down to normal and idled like a champ. everytime starting the car after that the idle was always dead on 750rpms. but now swapping back to stock injectors and maf, the car tries not to stall out. should i disconnect the battery for like 20min to reset the computer to make it idle better?

 

[BYRDPE]

thanks man u were right. i wasnt thinking under the fmu, because i assumed they were right. i swapped them around and my fuel pressure is now at about 60psi at idle, and the a/f is a little leaner. a/f bounces back and fourth between 12 and 14ish at idle now. so il try and bump fp down now to make it more optimal at idle. il tell u tho its idling crappy. it goes up and down and tries not to stall. wen i first started my car with the 42's and pro m, it was the first time i started the car in 6 months, also had a dead battery for all that time. it was idling alittle high for that first startup. but after idling for about 10min till i got heat in the car the idle dropped back down to normal and idled like a champ. everytime starting the car after that the idle was always dead on 750rpms. but now swapping back to stock injectors and maf, the car tries not to stall out. should i disconnect the battery for like 20min to reset the computer to make it idle better?

yes........

 

[clement]

back in 1996 when i got my first vortech, i hooked up the FMU lines backwards like that. thats why when you said it had 100lbs of FP i had a pretty good idea what the problem was. dead heading the pump at 100 psi might have trashed the fuel pressure regulator, so that might need replacement. or if its adjustable turn it down. you can pull the vacuum line off the regulator on the back of the rail and if the diaphram in it is trashed itll likely be spitting fuel up through the vaccuum port.

 

[t76stang1Day]

back in 1996 when i got my first vortech, i hooked up the FMU lines backwards like that. thats why when you said it had 100lbs of FP i had a pretty good idea what the problem was. dead heading the pump at 100 psi might have trashed the fuel pressure regulator, so that might need replacement. or if its adjustable turn it down. you can pull the vacuum line off the regulator on the back of the rail and if the diaphram in it is trashed itll likely be spitting fuel up through the vaccuum port.

well i hope i didnt mess the regulator up. it's the adjustable bbk regulator.

 

[clement]

pull the vacuum line off the regulator with the engine running, and if its not spitting fuel out of it then its probably fine.

 

[93GTStang]

Honestly I would stick the stock regulator back in the car. Even with the FMU hooked up you should not be seeing 60lbs of FP at idle. Set the fuel pressure to 39psi with the vac line off. Under boost you should see 12psi per 1 lb of boost if it is the right FMU for the 19lbers.

I ran a Powerdyne before on my old 93 GT, it worked quite well with the 19lbers/FMU. Ran times in my sig.

 

[t76stang1Day]

pull the vacuum line off the regulator with the engine running, and if its not spitting fuel out of it then its probably fine.

Did that and no fuel spitting out, seems fine to me.

I ran a Powerdyne before on my old 93 GT, it worked quite well with the 19lbers/FMU. Ran times in my sig.

Where u running a stock MAF sensor also? if so did it give u problems? I think mine is the reason why my car is idling so ruff, but i dont understand it. the fmu is hooked up right, the fp is now set at 40psi at idle. When i first start the car it seems to idle smoothly but after about 2 min of idling it starts to idle ruff going up and down and eventually stalls

 

[Kdubslugga]

60 psi of fuel is WAAAAY to much

 

[t76stang1Day]

it's now set at 40psi at idle

 

[clement]

cool deal.

 

[93GTStang]

Where u running a stock MAF sensor also? if so did it give u problems? I think mine is the reason why my car is idling so ruff, but i dont understand it. the fmu is hooked up right, the fp is now set at 40psi at idle. When i first start the car it seems to idle smoothly but after about 2 min of idling it starts to idle ruff going up and down and eventually stalls

I was using a 70mm Cobra maf, but even with the stock 55mm it was fine. Do you have a bypass? It almost sounds to me like you are having issues with unmetered air entering. If you have a bypass check all the connections. Post up some pics if you can.

These issues are only AFTER the supercharger install?

 

[t76stang1Day]

I was using a 70mm Cobra maf, but even with the stock 55mm it was fine. Do you have a bypass? It almost sounds to me like you are having issues with unmetered air entering. If you have a bypass check all the connections. Post up some pics if you can.

These issues are only AFTER the supercharger install?

the car was parked for about 10 months, until i started it. the first time i started it after so long i did start it supercharged. that was with the blow through intercooled setup that had the 42s, pro m meter, and tial 50mm bov. it seemed to run fine, the idle was very smooth like always, and it felt like it deffinitly had some power while driving around the block. only thing i didnt like was it was too rich a/f 10.8 at idle. i know i needed a tune, but with xmas around the corner i dont have the cash to get one right now. so i figured id try the stock injectors w/ fmu cause i had it lying around. right after i swapped the setup thats when it started acting up.

ill tape a video of it running tomorrow

 

[93GTStang]

the car was parked for about 10 months, until i started it. the first time i started it after so long i did start it supercharged. that was with the blow through intercooled setup that had the 42s, pro m meter, and tial 50mm bov. it seemed to run fine, the idle was very smooth like always, and it felt like it deffinitly had some power while driving around the block. only thing i didnt like was it was too rich a/f 10.8 at idle. i know i needed a tune, but with xmas around the corner i dont have the cash to get one right now. so i figured id try the stock injectors w/ fmu cause i had it lying around. right after i swapped the setup thats when it started acting up.

ill tape a video of it running tomorrow

Well I was running the Powerdyne the way it came so draw thru. I know on my LX when it had the ProCharger the meter was VERY sensitive to the clocking. Alot was due to the crap design that ProCharger has with a bend right before the meter. Try clocking the MAF and see what happens.

 

[t76stang1Day]

i will try that when i get home from work, thanks for the tip. it is currently clocked at the 12 o clock position. should i clock the maf while the engine is running?