E30 325i wont go above 4000RPM!!!
Discussion
I'd suspect the flap in the air flow meter could be binding.The throttle position sensor sits on the underside of the throttle body and over time oil leaks in - but whilst you can remove it, open it up and clean it out I don't think that's it.
It sounds like a fuel delivery thing or the ignition timing isn't advancing - that's an ECU or crank sensor fault. No cam sensor on the M20.
It sounds like a fuel delivery thing or the ignition timing isn't advancing - that's an ECU or crank sensor fault. No cam sensor on the M20.
Touring442 said:
I'd suspect the flap in the air flow meter could be binding.The throttle position sensor sits on the underside of the throttle body and over time oil leaks in - but whilst you can remove it, open it up and clean it out I don't think that's it.
It sounds like a fuel delivery thing or the ignition timing isn't advancing - that's an ECU or crank sensor fault. No cam sensor on the M20.
So should I take the afm off and clean the flap/wiggle it? What's the process you'd do It sounds like a fuel delivery thing or the ignition timing isn't advancing - that's an ECU or crank sensor fault. No cam sensor on the M20.
onthames said:
buggalugs said:
Are you able to check fuel rail pressure when the problem is occurring? Can’t remember how easy it is to get O2 sensor data on those, if you even have one.
No O2 sensor on my car I don't thinkAlso no idea how I'd go about checking fuel rail pressure. Cheers though
onthames said:
Problem is only under load idle rev is fine even when hot
I saw you've already changed the fuel pump and filter it was just that the symptoms fit loosing fuel pressure at high injector duty so thought it was worth double checking the pressure anyway, can't remember what info you can get out of that ECU in terms of live data but there might be some interesting numbers in there tooA post 9/87 build 325i will have Motronic 1.3 with the crank sensor on the front pulley reading TDC and RPM as opposed to the older system with two separate sensors on the flywheel. There will be a C101 plug for diagnostics - what can be read from it is debatable.
For what they cost, I'd replace the fuel pressure regulator. Make sure the vacuum pipe isn't leaking as well.
For what they cost, I'd replace the fuel pressure regulator. Make sure the vacuum pipe isn't leaking as well.
Touring442 said:
A post 9/87 build 325i will have Motronic 1.3 with the crank sensor on the front pulley reading TDC and RPM as opposed to the older system with two separate sensors on the flywheel. There will be a C101 plug for diagnostics - what can be read from it is debatable.
For what they cost, I'd replace the fuel pressure regulator. Make sure the vacuum pipe isn't leaking as well.
Will replace. For what they cost, I'd replace the fuel pressure regulator. Make sure the vacuum pipe isn't leaking as well.
Touring442 said:
So it won't go over 100 mph in 5th? They were geared up at around 25mph/1000.
Struggles at around 90 yeah. Sometimes lower depending on how long I've been driving. This is on track of course 
Cars currently in the bodyshop guys having full M-tech 2 kit fitted + painted so gonna be a couple weeks before I try any of this stuff. Will update the thread then and thanks for all the help. Hopefully its something harmless and nothing serious is damaged (like an ECU!)
E-bmw said:
Why?
I believe the car drives fine for a bit because over 20 or so mins flakes of rust etc from tank get sucked onto the sock filter on bottom of in-tank pump. Which is why restarting the car causes the problem to go away and then come back (turns off the pump, dropping the gunk off the sock)Tank needs replacing anyway, rust inside and is original and too much faff to clean inside, cheaper to get a new one.
Gassing Station | BMW General | Top of Page | What's New | My Stuff