PhatManBUD

Is the stock Fuel pressure regulator okay to use with a walbro 255 fuel pump? Cause for some reason my motor keeps flooding whne it turns over and kills it self then i take out the spark plugs and theres fuel all over them. I tried using smaller 550cc injectors to see if it helps and it doesnt. I have maps loaded from xs engineering. im thinkin the stock fpr cant handle all the fuel being pumped to it?

yodaddy

no, you may just have a bad fpr or the problem is somewhere else. I run a nippondenso pump on the stocker for now and it works fine.

maxcooper

Generally, your setup should be fine. I was running the BNR-32 pump with the stock FPR for a while and had no problems like the ones you describe.

Do you have a fuel pressure gauge? That would help with the diagnosis. Perhaps you can get a temporary one to troubleshoot.

Did you retain the stock 2-speed pump control system? Running the pump at a full 12v at idle might overpower the FPR.

Is there a kink or pinch in the return line? That might give high pressure at idle, too.

-Max

PhatManBUD

hmm im pretty sure there isnt a kink or anything in the lines cause the only thing i really changed was the mapping and the fuel pump. i plugged the vacuum off of the fpr into the uim.

maxcooper

Are you saying that you eliminated the manifold reference signal from the FPR? In other words, did you remove the vacuum line that goes between the FPR and the manifold (it goes through a solenoid, too, but we can ignore that for a moment).

If so, you will run rich at idle and lean under boost.

-Max

PhatManBUD

i took out the solenoid....and ran a line straight from the fpr to the uim

maxcooper

That should work fine -- I thought you plugged it at first.

-Max

PhatManBUD

damn. i thought you were onto something to fix it =\ i was looking at the vacuum diagram for the stock and it doesnt show where the fpr line leads from the solenoid. it goes right to where the primaries are and it doesnt show the rest

RotorJoe

Just as an FYI I run the walbro 255 pump with the resistor shorted (hi low mode) and the stock FPR. I have just piggy backed an SX FPR with gauge to it and have yet to remove the stock one. I doubt it is the FPR.

PhatManBUD

well if the fpr is rulled out then the only other thing it could possibly be is tuning...right?

Does that vac line coming off the lim matter...i believe i have that running to the intercooler piping now

but for some reason i dont think its the tuning cause xs did it and if anything it should be able to idle at the very least...im thinkin the fpr cause why else would it flood even with 550 cc injectors in?

RotorJoe

I know this is bad, but right now I have just cranked up the fuel pressure at idle by about 15 psi because I have not hooked up the vacuum lines to the UIM for boost pressure fuel increase.

I have just made sure that I run real rich at idle and rich at boost, however day by day one thing gets looked at and I can pull more fuel out. Soon I'll have all the bugs worked out.

Could your secondary injectors be leaking? What are you mods and what injectors are you running?

Sorry for coming in late.

PhatManBUD

mods are single turbo, 3" straight pipe. custom fmic. hks bov. walbro fuel pump. apexi power fc, rebuilt motor, 4 x 850cc injectors but i put the 550 back in to see if it will stop flooding. 6 puck clutch and light flywheel. and koyo radiator

RotorJoe

Do you have any sensors highlighted in the PFC?

I know if your you MAP sensor is not hooked up it will read close to 5 volts and the PFC thinks you are running full boost at idle. That floods it out really quick. And I mean the electrical connector not the vacuum line.

Just another area/suggestion.

PhatManBUD

Update on flooding issue:

Okay after giving up for a week. i went back at it yesterday. after unflooding it and cranking it this time. It turned over and instead of letting it idle by itself i held my foot on the gas to about 2,500 rpm. Tons of white smoke poured out the back (brand new motor pretty much has about 1.5 miles on it). I revved it to 3,000 and held it there to try and burn the stuff out of there. It stayed on like this for about 2-3 minutes and it just shut off, just died. didnt bog down and die this time, just shut off. I think its cause i was totally out of gas cause the gas gauge was below the E and ive flooded it quite a number of times now.

It was SOOO LOUD. straight 3" no cats or resonators, and an N1 exhaust. loud enough to wake up people 4 houses down. My friend said cause its a fresh motor. So...will the sound get a little quieter once its broken in? It was smooth at 3,000 but it just sounded like i was dumpping the exhaust right onto the ground after the turbo or something. Or like it had a crazy port job. just loud BRAWP, BRAWP, BRAWP, BRAWP, BRAWP, BRAWP, BRAWP, BRAWP, BRAWP, BRAWP
Still music to the ears after this long journey tho

So i went out and bought 2 gallons of gas and put it in and try to crank the car over and it was flooded again. I took out the FPR last night and bought an after market SARD adjustable, one with a gauge so i will be installing that in the next couple of days.

Any Input anyone?

Trexthe3rd

Why don't you just take your injectors out, pressurize the fuel system and see if you have a leak?

maxcooper

It will certainly leak with the injectors out! But I think you mean pull the rails with the fuel plumbing and injectors still installed. Then you could see any leaks. Be careful not to go up in flames. Keep a fire extinguisher handy and cover the holes in the engine in case you need to use it. Also, use a jumper wire in the diagnostic plug rather than turning the key to the start position -- it will run the pump without firing the ignition, and you can do it all from the engine bay where you can quickly pull the jumper in case it leaks.

-Max

RotorJoe

This sounds really close to what happen to me with my fresh motor. Check the injectors! My primary injectors were leaking from the top plastic caps, they could have been also leaking into the engine. I'm not sure. Either way I replaced them. They may have helped flood my fresh rebuilt.

Reload the map setup for the 850s all the way around from XS (that is if you still have 850s all the way around).

Go through a full deflooding and start it again. This time have a buddy watch your fuel pressure as you hold the car at 2500 or so. It needs to build compression still which could be part of the reason it floods soo bad. Plus it sounds like its been flooded bad. Keep it runnning for as long as possible.

But watch your fuel pressure while the car was running.

I ended adjusting the idle screw and set it at 1500 so I could check for coolant leaks and finish topping off the system. I let it idle for a half hour with some reving and holding up to 3000. The smoke will clear. I then took it for a short slow drive around the block. After about an hour running I shut the car down and crossed my fingers. I tunred the key again and it fired right up. The flooding problems were gone.

It could just be a badly flood really fresh rebuild. But the part where it just died could be a problem. Watch your fuel pressure.

Good Luck.

P.S. Change your oil after all of this. You'll notice it will have a lot of gas in it.

PhatManBUD

i have i have the same problems as you. i will find out if its holding pressure when the fpr is in. hopefully the guy that modified the rail for me gets it back by sat then its ready to go in.

RotorJoe

Oh and your injectors have been tested, I remember.

You should buy a or borrow a WideBand 02. Then once it does start watch the ratios and pull fuel out as needed. I hear a lot of people have idle and transition problems with running 850s as primary injectors. Thats been part of the reason I haven't upgraded to them. I think I'll go with the 1600s instead, but for now I don't need any more fuel.

Good Luck

PhatManBUD

yes they were all cleaned and tested.

I dunno why the fuel rail could be leaking cause...i mean i drove it before with stock twins and it was fine and the only thing i modified was getting the injectors cleaned, putting 850s in the primaries and upgrading the fuel pump. Maybe the fuel pressure reg is what i needed. i hope so. Maybe i just need to try and keep it idling for a while like you said.

Any reason my car is so very loud other then the straight 3" piping? is my compression really really high up since its still fresh. Guess i did something right. haha I guess its a good thing. total cop magnet tho. haha

geez, Everythings so custom...I wonder how everyone feels that you are far beyond the point of converting back to stock.

maxcooper

Putting 850s in the primary rail means big leaks, unless you mill the rail down or use extra o-rings:
http://www.wvinter.net/~flanham/wlan...el/850pri.html

What method did you use to install the 850s into your primary rail?

-Max

PhatManBUD

oh i know, xs said that if i put an extra oring around the bottom of the 850 and stick it in it should work fine...it flooded with the stock primaries in the rail too though...

madas7

I think its your tps. check calibration. make sure its still spring loaded from behind,
i think the power fc thinks your under full throtle or something.
I dont think its an injector or fpr problem at all

madas7

Ive had this problem before. idles like a bridge port because tps is telling computer you need more fuel. sometimes i forget to preload spring inside tps when its removed for engine cleaning during rebuilds. just need to check power fc make sure at idle your tps is reading closed throtle or 0 volts. i think .5 volts equals half throtle from memory

PhatManBUD

hmm really. ill check that next time i get it started.