Yet another fuel pump starvation question

[e30s50dan]

Ok. Got back from Roebling road .e30 with S50 G240 bilstein H&R spring stock brakes Toyo r888 with ht10 hawk pads..started with half tank of gas,but after my first run it was starving in right hand turns.filled up near full,rest of day was great,but at the end of day,still with near full tank,the pump was noisy and car was missing everywhere on track..I didn't run on Sunday,didn't want to chance a blown engine

This was my first event with a e30s50 ,and it was a blast! I've been going to roebling road for 14 years,and know the track well..it showed,because I was passing about everyone.many new 997's,993's,c2's,944's968's and of course miatas..only gt3s and corvette was quicker..I did weigh the car there and surprising it was 2475lbs with full tank.

Anyway,the pump..do I get a new VDO pump and keep it at half full? I have a 91 318 with the cross over pipe Tank,that I am wondering will this be a better tank?

Thanks,will try and post some video

TIA


Dan

[91Saleen#15]

I ran my s50 powered 91 318is last weekend. After a long right hand sweeper the car leaned out for a second, so I filled the tank. It only took 4 gallons, but the problem went away.

[rThor432]

You might want to check the in-tank pump screen too. I understand the issue of starvation, but I've seen clogged screens at the track cause a restriction (obviously..) that over works the external pump.

Edit: Just noticed you are running an '88; you don't have an external pump. Due to your mention that the pump was noisy with a near full tank, I'd definitely check the in tank screen. The last car I had this issue with was an '88 turbo M20. Cleaning the screen had the car driving great. A can of carb clean works well.

Off topic-- have you hit any other local-ish tracks with the S50 and stock brakes? Curious to see how they hold up. I can see why Roebling wouldn't cause any issues with them, but I wonder about VIR or CMP-- a track that stresses the brakes a bit more. I bet RRR was fun with the S50 though.

[Dave]

If you have the single pump setup, those pumps do NOT like to be starved. DO it more than a couple times and they can fail.

Another thing to check is the fuel pump relay. It and the other relays that reside by it should be zip tied on an e30 - they can work themselves loose.

[e30s50dan]

You might want to check the in-tank pump screen too. I understand the issue of starvation, but I've seen clogged screens at the track cause a restriction (obviously..) that over works the external pump.

Edit: Just noticed you are running an '88; you don't have an external pump. Due to your mention that the pump was noisy with a near full tank, I'd definitely check the in tank screen. The last car I had this issue with was an '88 turbo M20. Cleaning the screen had the car driving great. A can of carb clean works well.

Off topic-- have you hit any other local-ish tracks with the S50 and stock brakes? Curious to see how they hold up. I can see why Roebling wouldn't cause any issues with them, but I wonder about VIR or CMP-- a track that stresses the brakes a bit more. I bet RRR was fun with the S50 though.

I will take a look at the screen. Can you buy just the screen?

And I will be going to VIR in July,this will test the brakes!

[rThor432]

I will take a look at the screen. Can you buy just the screen?

And I will be going to VIR in July,this will test the brakes!

You can buy just the screen, but I don't know exactly where to go for it.. I don't think you can buy it through BMW. I think that it is a fairly generic filter screen for a Bosch in-tank pump, so if you treat it as a generic part you might even find one at Advance or Auto-zone. I'm not sure.

Sounds excellent, I don't honestly see why the brakes wouldn't be just fine if they are set up properly. They do great on all of the Spec E30 cars I've worked with (granted, you have almost 2x the power..).

[e30s50dan]

Yes. I was worried about the brakes not being adequate, but my car weighs less than the specE30's. CMP would be the true test for stock brakes here on the east coast..

I will check advance auto for the screen

[gearheadE30]

fwiw my local Napa had a fuel pump from Delphi for my 318is. I think it ran me $65. It's just the pump body though; you have to install it in the mounting assembly.

My car also has the starvation problem if I'm below about 3/8 tank of gas. Right-hand high-g sweepers cause the car to cut rather badly, and I can't afford to run lean with the turbo, so I'm also looking for a solution... an accumulator chamber of some sort would help, but it wouldn't solve the problem with the pump not getting fuel.

[jlevie]

This subject has been covered before (try a search). My solution can be seen in http://www.r3vlimited.com/board/showthread.php?t=157887

[e30s50dan]

Yea I read that. Twice ! I'm going to replace my stock pump first and see what happens. I have no issues right now on the street..starts every time and runs fine!