E30 M52 Conversion Still Lacking Power???

[tbone455ci]

Still the e30 M52 conversion is lacking power? I was expecting the Bimmer to be quicker not f`ing slower ;)

I got another fuel pump of eBay, an original e30 pump & fitted it today. Went for test drive and it was worse then before. Spluttering from 3000rpm onwards. This pump seems to be hunting not buzzing like a normal pump, dodgy pump?

Put the scanner on & no codes. It's not misfiring or missing but splutters & holds back?

I put the old pump back on. There was an improvement but still holding back & Spluttering at high revs, well 3000 +

I'm thinking it maybe the `Fuel Pressure Regulator`. Going to do a pressure test on Monday (need to borrow a tester).

I have put a video on YouTube showing the symptoms.


Also when slowing down on over run, there is a lot of popping from the exhaust. Unburnt petrol noise, it does sound good but I'm pretty sure it shouldn't be doing this.

When the engine cools it's not as bad but you can still feel it holding back. Has anyone had the same or similar problems?

It's really p****** me of now, booked a day for Drifting next week & need to get the Bimmer sorted asap!

Any help much appreciated......

Apart from this big problem, the engine starts 1st time, Idles smooth, pulls great from start until the revs get to 3000 plus?

I fitted a cam sensor last week that was coming up on the scanner and that cured the misfire it had but not this lack of power???

[hongkongfuey]

Have you checked lambda sensors

[hongkongfuey]

Have you checked lambda sensors

[tbone455ci]

There's no code coming up for the O2 sensors & I have tried disconnecting them and its still the same.

I been checking google and someone had the same problem and swaped his ECU for a S50 ecu and it was ok after?
http://www.r3vlimited.com/board/showthread.php?t=176617

The symptoms he had are the same as mine.....
http://m.youtube.com/index?&desktop_uri=%2F

[leeparkes]

Fitting an S50 ECU would just be masking the problem IMO

[jmc330i]

I been checking google and someone had the same problem and swaped his ECU for a S50 ecu and it was ok after?
http://www.r3vlimited.com/board/showthread.php?t=176617

I expect that their talking about the S52, the US M3 engine. It's basically an M52 so the ECU swap would work for him.
I'm not even sure an S50 ECU would run an M52.

Does it rev cleanly past 3k rpm when stationary? Have you connected the road speed signal?

[DanThe]

Im surprised there are no fault codes, do you know what the machine is thats reading the ECU? Loss of fuel pressure seems like the obvious choice at the moment, try clamping off the return pipe from the pressure regulator

[tbone455ci]

Hi mate

It seems to rev past 3000 when stationary but not past 4000. When driving you notice a lack of power past 3000 and a big drop past 4000.

The speedo works ok and sensor on diff is connected so I dont think that would be the problem. DanThe done a great job on the loom and deleted the ews from the ecu.

Im kind of stuck now with what it could be

[tbone455ci]

Hi mate

Using my mates Snap on scanner for reading the codes, it is shown the codes below but no new ones not even a misfire, which I thought it would have, as when it revs past 4000 it proper splutters cuts out?
http://m.youtube.com/index?&desktop_uri=%2F

217 CAN: Timeout AGS/EGS 
68 Tank Venting Valve: Electronic Fault 
52 Exhaust Flap Solenoid Valve 
100 ECU Selftest 

I have a feeling its fuel related too. Do you mean the vacum pipe on the regulator or the fuel return pipe? Would this let it rev past 4000, meaning the pressure regulator is faulty? Will try that tomorrow!

[DanThe]

Yes the return to tank pipe, clamp it off to see if you can build enough pressure, defo sounds like fuel starvation

[tbone455ci]

Cheers mate

Will do that tomorrow, fingers crossed it will point me in the right direction....

I might be reading into this a bit to much but I have also found this:
The M52 ECU needs a speed pulse signal from the ABS sensors, this limits the ECU to 4-5K RPM if it can't find this signal.

I have my abs disabled, could this be the problem? But I cant see this affecting the revs when the car is stationary......hmmmm

[DanThe]

Cheers mate

Will do that tomorrow, fingers crossed it will point me in the right direction....

I might be reading into this a bit to much but I have also found this:
The M52 ECU needs a speed pulse signal from the ABS sensors, this limits the ECU to 4-5K RPM if it can't find this signal.

I have my abs disabled, could this be the problem? But I cant see this affecting the revs when the car is stationary......hmmmm

Take no notice of that, if it was an issue you would have a fault code for it

[Brianmoooore]

If it was lack of fuel pressure, wouldn't the lambda sensors be showing a code?

[DanThe]

Possibly, ive had lambda fault from running lean on LPG but it took a lot of running for it to show. The only other thing I can think of is a snide cam/crank sensor, they dont always show a fault

[JF008]

Wouldn't you need a fuel pump that match your engine? I don't mean to sound patronizing, its a genuine question

[jmc330i]

No, the E30 fuel pump is fine for the M52, they all run 3bar so the standard pump is fine.

As you're using one of Dans looms, the speed signal shouldn't be an issue.
Did you replace the cam sensor with a decent one? I've experienced some dodgy cheap ones that don't show a fault code as Dan said. We swapped sensors between engines and the running issue followed the new cheap sensor.

[JF008]

No, the E30 fuel pump is fine for the M52, they all run 3bar so the standard pump is fine.

4 to 6 cyl. too? was there only one fuel pump fitted to all models?

[jmc330i]

No, the E30 fuel pump is fine for the M52, they all run 3bar so the standard pump is fine.

4 to 6 cyl. too? was there only one fuel pump fitted to all models?

2 pumps depending on the age of the car. Early cars have an external pump, the facelift cars have an in tank pump (some early facelift cars had an external pump iirc). No difference between 4 or 6 cyl pumps.

[Cook318IS]

It couldn't be something as simple as a blocked fuel filter?

[tbone455ci]

Just got back from my mates garage. I clamped of the return fuel pipe hose and went for a run. It felt a little better but still not going like it should.

Plugged the scanner in when I got back and it had 2 new codes:
203 O2 Bank 2 Control Limit
202 O2 Bank 1 Control Limit

Could this be due to over fueling because the return hose was clamped? Cleared the code and it hasn't come back.

Then I fitted a welded diff, oh yeah it drives shit now but will have to do until I can get a lsd.

I reclamped the return hose for mymdrive home. The engine temp was just above the blue mark. Now it revved to around 6000rpm but still felt like it was holding back. When the temperature got up to half way mark it was doing the usual, losing power at 3000rpm and spluttering at 4000rpm.



Watching other e30 m52 conversions on youtube, the rev counters fly up after 4000rpm but not mine....

Then at the traffic lights it cut out, started after a few seconds like it had fuel starvation. Pulled over and removed the clamp andnit never died out again but still not revving beyond 4000rpm?

I did buy a euro part cam sensor last week which showed up on the scanner & cured the misfire I had. No cam sensor codes have come up since.

So I believe it could be
Fuel pressure regulator but not convinced.....
Dodgy cam sensor? Dont want to change it if its ok....
O2 sensors playing up? Code only came up today after clamping return hose? Is it usual for both to go?

I bought the engine of eBay and the add said it was running great, no misfire, no overheating, 90, 000 miles etc. So im a bit surprised ive had all these teething probs with it....


Thanks for your help so far....

[BMW_E30vert]

where about in London are you? ive got a working genuine bmw cam sensor that you could try, to see if it is the cam sensor or not?

[tbone455ci]

I live in leyton e10 by the orient football pitch....

[BMW_E30vert]

Im in Wembley so not too far

[tbone455ci]

Yes mate that would be great, I work in chingford but going to try & get tomorrow of. Are you busy tomorrow?

[DanThe]

Have you got the lambda sensors plugged into the right connectors?
If the sensors are faulty it will usually go into limp mode, 5300rpm max

[tbone455ci]

I did get a bit confused about that when you done the loom you said I had them labelled the wrong way around. When I fitted the manifolds to the engine I may of got them mixed up but I swapped thm around last week and disconnected them when it had the misfire and it didnt seem to make a difference?

I put them back how they were but havent tried swapping them since I had this power loss above 3000 to 4000rpm.
It doesn't rev past 4500rpm when warm, could it be that simple??

I only got the O2 fault code today when I clamped the fuel return pipe and it idles and pulls great until 3000rpm the power starts dropping of and at 4000rpm just splutters....

[SteSE]

Did you get this fixed dude? I have a very similar problem with my m52 conversion

Symptoms are it rev's right the way round when in neutral / not under load
In gear it's as though it hits a limiter at 4.5k ”“ see rolling road print out below



Uploaded with ImageShack.us


Have come to the conclusion that it is fuelling related. My car is a 1986 with external pump which whines like nobody’s business. I used to get occasional fuelling issues when it was an M20B25

Purchased an aftermarket pump to mount in-tank but my fuel tank is too small for it. So I’m going to get a facelift fuel tank and try again with new facelift setup.

Danthe ”“ I’d be interested to hear how you are fuelling yours as yours is a pre-facelift model

[BMW_E30vert]

Did you get this fixed dude? I have a very similar problem with my m52 conversion

Symptoms are it rev's right the way round when in neutral / not under load
In gear it's as though it hits a limiter at 4.5k ”“ see rolling road print out below



Uploaded with ImageShack.us


Have come to the conclusion that it is fuelling related. My car is a 1986 with external pump which whines like nobody’s business. I used to get occasional fuelling issues when it was an M20B25

Purchased an aftermarket pump to mount in-tank but my fuel tank is too small for it. So I’m going to get a facelift fuel tank and try again with new facelift setup.

Danthe ”“ I’d be interested to hear how you are fuelling yours as yours is a pre-facelift model

are you sure its not running in limp mode? did u get a computer on it to check fault codes?

[DanThe]

Danthe ”“ I’d be interested to hear how you are fuelling yours as yours is a pre-facelift model

I fitted a 63 litre tank and pump/loom