odd KA24de fuel problems

[chixwithtrix]

I've been having a lot of fuel problems with my '91 KA. It is in a track only drift car so it gets beat on pretty good and sits in between events, 125k miles. I am picking up an RB to swap in in a few weeks so this engine is getting tossed, but there is an event coming up before I will be starting the swap and I need to get the KA running right. Also if the problem is with something other than the engine I would like to fix it so the RB will not have any issues.

Anyone know what might be going on here, please ask if you need more clarification.

First thing is that the injector o-rings like to break a lot and cause flooding. I worked off and on with this for a few days and realized the o-rings needed more lubrication when installing, but minus the ones that broke becasue of that I've been through 2 orings on each of the front two injectors in 2 months. Old injectors, fuel issues, rail issues?

At the last event the car would have a fuel cut when we pulled any Gs during a drift. I filled up the tank and charged the battery and it seemed to mostly solve that problem, but what could it have been specifically? Later it would start dropping a cylinder and run horribly off and on for the rest of the day. I checked the injector o-rings there at the track in the morning, but they seemed fine at that point. I checked the spark plugs and they were white, so it was running lean during that part of the day. What would casue it to run lean?

Sometimes the car would just randomly loose all power in the middle of a drift and die even if we gave it some throttle to keep the RPMs up, it just felt choked or a prolonged fuel cut. Sometimes when it would drop a cylinder (or two) we could give it throttle and past 4k RPMs it would smooth out and run fine.

Towards the end of the event I started to smell fuel whenever I was near the engine bay (still running on 3 cylinders) and at that point I just gave up on trying to find out what was wrong and tried to make the most out of what practice time I had left. If we shut the car down the engine would not want to start without giving it some gas pedal. Especially if the engine cooled down.

Lots of little issues, but I think it has to come back to one main issue...any help would be greatly appreciated!

[480sx]

Fix your fuel leak first then get back to us. Pull the fuel rail off the car, and prime the pump a few times. Put a paper towel or something under the whole rail so you can tell where its leaking from.

It would also be helpful to get a fuel pressure gage rigged up so you can see whats going on.

[chixwithtrix]

Thats the thing, I do not have a visible fuel leak. The only leak I have been able to find so far is the lower injector o-rings, and the engine has acted this way even when I knew the o-rings were good. Is there another common place that fuel could be coming from other than the rail? I’ve taken the rail off w/ the injectors in it and put some cardboard under it, primed it, and went through the starting sequence and nothing was leaking. All injectors were firing.
Modified by chixwithtrix at 6:57 PM 7/9/2008

[liquid_cool]

have you though of the fuel tank being the issue?..you said when you pull G's it cuts out..you might need a baffle or a way of keeping the fuel intake line in the tank in fuel all of the time..you allso might wana check the fuel filter..it might have a large piece of debris in it..just a thought..good luck.

[chixwithtrix]

ah yeah, that is a good point about both. I'll have to check the fuel filter, I don't know when it was changed last. Would a dirty filter cause all of these type problems though?

[xckid]

AS far as fuel cutting of while sitting sideways its probaly your gas sloshing around and away from your fuel pump causing it to starve. That happend to a friend of mine causing is car to die mid drift and slammed into a wall. maybe time to go fuel cell?

[chixwithtrix]

Is there a simple way to check if the baffles are still working in the tank? If I get to it from the hole in the back of the car can I visibly see if the baffles are messed up?

[chixwithtrix]

and as for the lean issues, would removing the EGR and having a shortpipe cause the cylinders to get too hot and cause a lean condition?

[chixwithtrix]

anyone?