Fueling problems

[biketrey]

Hi all,

I've had quite the experience with my coldside kit. I bought it used last spring and have had to have it rebuilt TWICE by Magnuson. Luckily, they honored the rebuild both times but, as you can imagine, it was quite a pain to not only take the blower off once, but twice.

Anyhow, I finally got the blower back with all new internals (the first time, they didn't replace the rotor), and installed it this past weekend and now I'm having trouble with fuel. Let me explain...

When first starting the car, I need to pump the gas pedal a couple of times to get the car to 'catch'. Once caught, it sputters for a few seconds and then comes to life eventually settling into a nice smooth idle. No problems while driving, even pushing the car hard doesn't seem to cause any problems.

If I turn the car off and start it right away, it behaves normally and starts right up but if I let it sit for even 5 minutes, it takes a few seconds to start....not quite as sputtering as when cold but still...

I've been exchanging emails with Tom (Thanks Tom!) who thought it may be a small fuel leak or a vacuum leak somewhere but I don't smell any gas at any time and my vacuum as at about 20-21 when idling.

Any ideas on where I should look? Thanks in advance

[Satisaii]

Sounds like the fuel pressure regulator is not holding pressure after shutoff.

[bogey]

Ditto. Classic open FPR. Pull it off and see if you can blow through it. If so, it bad.

[biketrey]

Forgive my ignorance; where is the FPR? In the tank or somewhere along the fuel lines?

thanks!

[Satisaii]

If you have a 99/00, then it is in the tank.

[Gman7007]

Quick description of the 99 system in this thread.

http://www.fastforwardsuperchargers.com/forum/showthread.php?t=1550

[biketrey]

Thanks all! I'll take a look when I get home tonight.

[biketrey]

The thing is, if the FPR is bad, will the car still run?

[Satisaii]

Yes. It does 2 jobs. One is regulate pressure when the pump is running. The other is to hold pressure for a period of time after the car is turned off to make the next start easier. The best way to check is to put a pressure guage on it, but that is not easy. I would not get on it until you get it checked out. It could be running lean.

I just thought of any easy test (if you are comfortable with the electronics side of the car.) Just energize the fuel pump before cranking by hooking it to a 12V source. If this fixes the problem, then the FPR is bad. I did this to decrease cranking time on the first start after a rebuild.

[biketrey]

Not too comfortable. I was pretty proud of myself installing the darn SC not once, but 3 times! but I think with electronics, if there's a schematic or good directions, I can follow, but otherwise, I'm pretty lost. I need to take it in somewhere and have the codes read.

thanks a bunch for your replies. I'll update the thread once I have a firm diagnosis.

[biketrey]

I jumpered the diagnostic module to energize the fuel pump. Will this do the same thing as you suggest below? If so, it may not be the FPR after all...after I pressurized the fuel system, I removed the jumper and then tried to start the car. No difference.

I'm taking it into a shop tomorrow but wanted the opinion of the board as to what I may expect.

thanks in advance!


Yes.

I just thought of any easy test (if you are comfortable with the electronics side of the car.) Just energize the fuel pump before cranking by hooking it to a 12V source. If this fixes the problem, then the FPR is bad. I did this to decrease cranking time on the first start after a rebuild.

[Satisaii]

Somebody else will have to speak to that. My wiring harness does not have the stock test ports. I have direct access to the wire going to the fuel pump.

[biketrey]

Okay, it's diagnosed...the 5th injector is leaking/dribbling fuel. Tom's sending me a new injector. Whew!! I'm glad that's over!