Car is acting weird on turns

[NcTurnL]

Hey

im noticing whenever I take a sharp turn to the right ( haven't tried to the left yet) my car bogs for about a solid second, then it goes back to normal. Its so odd and annoying. Oddly enough, it doesn't do this while im drifting. Only when im trying to grip turns. I have spoken to a few people and this is what I got:

- Fuel starvation- when the car turns hard to the right ( haven't tried to the left) the car doesn't get enough fuel and starts to bog **Keep in mind this isnt a bog bog bog type deal, its a solid second long bog with my foot to the floor** This idea sounds very plausible, I havent checked yet with different fuel levels.

- Clutch slipping- I thought it was this for a while. With the addition of the LSD, I thought it was alot of stress on the clutch, so it would just slip, although it FEELS like the car is slipping, the RPM dont go up.

- Diff - Someone brought up an idea that it could be diff havening problems, the clutches inside might be slipping, but in this case, wouldn't one wheel still HAVE to spin? I am getting NO WHEEL SPIN on these turns btw.

Any help would be appreciated!
this is on a 325i with a 3.73LSD and suspension.

Thanks
-Jon

[Tangent]

Fuel starvation is the most likely culprit. Drifting doesn't generate the same g forces as maintaining traction. A tire can lose up to 20% of it's total grip when it starts to slide.

[SamE30e]

Fuel starvation.

Maybe your AUX pump is gone.

[ddavidv]

What the guy above said. Try it with a full tank and see if it goes away. If it starts when the tank is half or less...aux pump/sending unit in the tank. Not hard to replace at all. There is an access panel under the rear seat cushion.

[NcTurnL]

that interesting because I thought E30s only had one fuel pump?
So thanks everyone for pointing me in the right path, now can someone explain this aux fuel pump? lol.
Im going to fill up my tank and give it a try and see what happens, in the mean while though I gotta try to find that aux fuel pump, I remember going under the seat and fixing the level sender, when I pulled out the pump, I thought that was the only pump.hmm.

Also, thanks tangent for that grip fact, I never knew that, I thought it would be alot more!

[TrackAddict]

1988 and newer E30s only have 1 fuel pump and it's inside the fuel tank. 1987 and older cars have two fuel pumps. For the 1987 and older cars, the booster (or auxilliary) pump is located in the fuel tank and the main fuel pump is just to the left of the fuel tank near the fuel filter (in front of the left rear wheel).

This seems to be a very common issue with track-driven E30s. My car does it during hard left turns when my fuel level goes below 1/2 tank. I'm in the process of replacing both fuel pumps and the main and fuel pump relays. Hopefully, this will be the end of it!

[NcTurnL]

Ok their we go, thats what I was gettitng confused about.
But im still a little confused, so my car as it being an 89 has one fuel pump and an booster pump ( which is not considered a fuel pump)?
If so, which one is the main and where is the booster on mine, I know one of them is under the pass. rear seat, but where is the other one?

[TrackAddict]

Ok their we go, thats what I was gettitng confused about.
But im still a little confused, so my car as it being an 89 has one fuel pump and an booster pump ( which is not considered a fuel pump)?
If so, which one is the main and where is the booster on mine, I know one of them is under the pass. rear seat, but where is the other one?

Since your car is an '89, it should only have one fuel pump. That pump will be located inside the fuel tank, under the rear passenger seat.

[NcTurnL]

So there is NO booster pump then?
Then what could I do to help stop this problem im having on turns?

[DCColegrove]

So there is NO booster pump then?
Then what could I do to help stop this problem im having on turns?

Not on an 89 if that is what we are talking about, the main pump is in-tank.

I would put a fuel pressure gauge on it and see what's happening. Run the tube out the hood---don't shut it all the way--- and tape it to the windshield.

I have had some weird ones in the past including a bad AFM and a catalyst broken loose that caused power loss related to G changes.

[TrackAddict]

I've heard of people having problems with a worn out fuel pump relay opening the circuit during high-g turns with a resulting fuel flow cut-off and power loss. In fact, I'm replacing my main relay and fuel pump relay anyway since they look kind of old. They're not expensive and it's a good preventative maintenance thing to do anyway. Good luck and wish me luck, too!

[NcTurnL]

thats interesting, hmmm.
Imma going to actually try that fuel pressure idea pretty soon, its a good idea.

Is there any way of checking the fuel pump relay to see if its actually doing that? Where is the fuel pump relay and the main relay? If this is the problem, that would be odd....

Also, would a higher flowing fuel pump help my problem?

[NcTurnL]

Does anyone think a check valve in the fuel line and a higher pressure fuel pump would do ayn good?

[Tangent]

I doubt a check valve would do any good at all. At best a higher pressure fuel pump might mask it, but even that's unlikely.