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Fuel pressure/pump/regulator

Posted: Mon Feb 17, 2014 11:41 pm
by M1ke30
I've got the M52 (220bhp) in my 1990 316. Just a few questions about fueling. But to fill you in first, I'm just back from the rolling road and my AFR is 16:1 and running as hot a hit thing! The tuner says it's being starved of fuel. Luckily I had planned a turbo conversion so I have most of the fueling bits for that

My questions

1) what fuel pressure would the m52 require, 3bar??
2) are all the e30 pumps the same or do they differ between engines?
3) I have a walbro 255 in tank pump to replace mine, has anyone had anyexperiances good or bad with them.?
4) can anyone suggest an aftermarket FPR to use? Or are they not needed? Links would be great if u can.


Thanks in advance.

Re: Fuel pressure/pump/regulator

Posted: Mon Feb 17, 2014 11:45 pm
by M1ke30
Just reading on a spec for the pump it's about 80psi for that pump. Thoughts?

Re: Fuel pressure/pump/regulator

Posted: Mon Feb 17, 2014 11:51 pm
by ross_jsy
1. m52's require 3 bar.
2. Is it a 316 or a 316i?
3. People use them, they are good pumps.
4. Why do you need an aftermarket FPR? The standard one on the fuel rail is a 3 bar one, and if you are providing the fuel rail with more than 3 bar, it will maintain it at that. I would suggest your running problems come from elsewhere. Is it the standard ecu?

Re: Fuel pressure/pump/regulator

Posted: Tue Feb 18, 2014 7:14 am
by M1ke30
Now that's a reply! Lol. Wasn't sure if I needed a aftermarket fpr, I was just going to address it since I was fiddling with the fuel system. At least it would have been done. lol. Ya running the standard 328 ecu. I had it on the diagnostics and it's thrown the engine speed crank position sensor. So going to change that, the fuel pump and filter and see how I go from there.

Would the cranks sensor cause it to run lean??

Re: Fuel pressure/pump/regulator

Posted: Tue Feb 18, 2014 7:35 am
by M1ke30
Also as far as I'm aware it's a 316 lux auto

Re: Fuel pressure/pump/regulator

Posted: Thu Feb 27, 2014 7:43 pm
by M1ke30
so can anyone suggest an aftermarket FPR for the M52 with a gauge preferably, and any advice on fitting and any adapters

Re: Fuel pressure/pump/regulator

Posted: Thu Feb 27, 2014 7:52 pm
by DanThe
You dont need an aftermarket pump or FPR, by doing this you are more likely to introduce problems than solve them

Re: Fuel pressure/pump/regulator

Posted: Thu Feb 27, 2014 9:13 pm
by Brianmoooore
By all means connect up a temporary pressure gauge to check that the fuel pressure is being maintained at the correct level, but if by any chance it's not, then either your fuel pump or FPR are faulty. Clamping the return fuel hose determines which.
Which ever is faulty (I doubt that either is) needs replacing by an identical, but working, version of the same, not some aftermarket tat.

Re: Fuel pressure/pump/regulator

Posted: Thu Feb 27, 2014 9:30 pm
by M1ke30
the fuel pump has just been swapped for a Walbro 255 unit as i'll be needing the extra pressure when the turbo finally goes on. along with the 60lb injectors.

Re: Fuel pressure/pump/regulator

Posted: Thu Feb 27, 2014 11:14 pm
by ross_jsy
You will be able to get 478 hp from 60lb injectors at 3 bar, are you really going to need extra fuel pressure? Bear in mind 5 bar will see you 618hp (both calculated assuming maximum 80% duty cycle)

Get it running on standard fuel pump/management before changing stuff.

Re: Fuel pressure/pump/regulator

Posted: Sat Mar 01, 2014 11:38 pm
by DanThe
rich318i's mate?