Starting/Idling issues and fuel pump question

[Clawhammer]

I've searched, and read a couple of the threads on this first page that are similar to my problem but not exactly and I don't want to thread hijack. I've also posted last month in the wrong forums (oops). Didn't get much help, maybe I can get more here since the guys that browse this section probably have more knowledge.

Ok, I have a 90 SOHC AUTO.

It takes a little bit of a cranking to start it unless I put my foot on the gas while cranking to give it some air. It also doesn't fast idle. And after starting it runs very rough for a bit, sometimes even stalling. Also my idle at traffic lights is bad after a few minutes when the engine is running at temp. The tach hunts between 3-500rpms so I have to put it in neutral and then it hunts between 800-500rpms but doesn't feel like it's about to stall.

It's got all new plugs, filters, etc. Timing is on. I don't think adjusting the idle is going to do anything because after running for a long time it idles fine...and turning on the AC bumps the idle up to the right numbers.

After research and speculation I'm thinking it's a fuel problem? Maybe a fuel pressure problem. If I need a new fuel pump should I replace it with a stock one or a Walboro 255? Keeping in mind that down the road I plan on a swap and with forced induction. Basically, is there any reason not to use that fuel pump on a stock KA?

Any any other input would be greatly appreciated.
Modified by Clawhammer at 1:35 AM 4/5/2007

[240sxmech]

Might have a leaking injector since you said its hard to start unless you let more air in , leans me toward an injector flooding out and when you hold the throttle your bringing the air fuel ratio back down so it can start.Check your TPS sensor also might be out of adjustment . Good luck and let us know what you find.

[Cleveland180]

You can use a 255 with a stock engine because any extra fuel pumped in will go back into your gas tank... and It's not loud really, so that wont bug you either.

[Clawhammer]

Ok, one if not all of the problems is the fuel injector wire harness. The really rough idle turns out to be nonfiring cylinder and wiggling the wire brings it back into play. Anyone know where I can get a harness? I'm guessing it's gonna have to be from Nissan.

I've checked the booty cd's FSM and Chilton's and no info on replacing it, so does anyone know anything about doing this before I dive in face first?

Thanks.

[Clawhammer]

Well I picked up 4 fuel injector pigtails from Nissan @ $10.95 ea. Cut/Solder/Heatshrink and the idling is fine.

Also did a fuel pressure test. I think my regulator is f'd up. As soon as I turn the car off the pressure starts dropping. But where is the fuel going? Back to the tank? I don't think it's leaking into the engine because there isn't a poof of black smoke or anything when I start it. Also when doing the vaccum checks the regulator does the OPPOSITE of what it's supposed to do. Any ideas on that?

My air regulator is also dead and that's why I have no fast idle.