Not going past 2500?

[equate975]

Drove the s52 e30 today finally after sorting the clutch hydrolics out.

It wont go past 2500 rpm though, I can get it to do it, if I just floor it through first and just stop the gas, but it complains about it.

When it gets up to 2500 it starts bucking and stuff aalmost lugging or stalling. Feels like its not getting enough fuel, maybe the O2 is bad and not mixing right? And going open headers with no backpressure it just can figure out the right AFR so its limiting me?

I also have #24 injectors, would a bigger fuel pump maybe be needed? Its just running the e30 ones now.

Thanks

[permit]

I had this same problem for one night about three days ago. I would get to 5k and the engine would start struggling, but if I kept the gas down, it would eventually work through to the redline. My O2 sensor has been busted for about two months, so I doubt it was that. It felt like a computer problem--like no gas, or no air, but it's gone now, so I don't worry about it.

[jrez]

Can you pull any codes from it?

[equate975]

My check engine light was on, but with all the mods to this engine along with the swap I didnt think anything about it.

I dont have a code puller or anything, but I will try to look into it and see if someone has one I can borrow. How much do they cost anyways? Probably a good tool to have around.

EDIT

I guess they are like $150, I see other type too besides turners Peake Research Fault Code Reader, Would it be able to pull codes correctly from a s52 with OBDI though?

[jrez]

Mine is a Peake research one also, but my car is OBD2. However I have used it on as far back a BMW as 1988, and it worked.
Im confident the Peake tool will work as long as the engine diagnostic plug is correctly wired.
Let me know what year car the harness(OBD1) is from, and I'll see if it's covered.

John

[KangamangusDriver]

Mass Air Flow sensor ??? Bad Coils???

[equate975]

Its an e34 OBDI harness, I dont know what year it was.

I dont think its the MAF since it can rev up to redline when I am not in gear, same with the coils.

[jrez]

Peake will do it. Just make sure the diagnostic port is wired correctly. As long as your e30 pump is in good shape,preferably new, it shouldnt be a problem. That's what I have also. Would be good if you could check the fuel rail pressure when this is happening.
So it revs cleanly when not in gear and stationary? My car when it did'nt have the vehicle speed input would shut down at 5500 rpm cause it was in default mode. You really need to get the scan tool 'cause you're going to have be able to clear codes after you fix faults.

[equate975]

Yeah, I will order one up then I guess. Why whould the diagnostic port be wiried wrong? I never even touched it for the swap.

[jrez]

It should'nt be a problem, but both m50 swaps i've seen in person for whatever reason had the diagnostic plug inop. Probably something as simple as not powering it up, but I don't know for sure.

[equate975]

Alright, sounds good.

So Peake is the best on the market now? Or is there a better cheaper undergound underdog that everyone like?

[KangamangusDriver]

Strange that you mention this

On my drive home the other day my M50 started to do the same thing
Car sat overnight and was fine the next morning
Drove to work today in a light mist and it occured again

No power after 2500rpm
Step on it, it falls on its face and then surges
Ive noticed that this happenes when it is wet out
Cleaned and re-oiled my filter
Same problem. Thought moisture was getting through the filter and on MAF.

If I rev it in neutral it seems to rev fine. (most of the time)
New fuel filter as of one month ago.


I spoke to a BMW tech and he said to check the MAF, Then the rubber seal on the bottom of the coil pack. Moisture intrusion possibly??

Any ideas or insight will be helpfull.

All my wiring is soldered and shrink wraped.

Throttle position sensor??

95 M50, OBD 1. E34 harness, 93 325i 413 ecu

[Skafrog]

LOL
I have this problem, but it is so intermittent that I cant track a set of situations that makes it happen.
I have changed the cam sensor, MAF, and plugs.
If someone find out what the solution is, please let us all know.

[puusitalo]

Have you guys checked the ignition coils ? Remove them from the car and check connection between ignition coil and ruber spark plug boot/"hat". Also check if there is oil or moisture in the spark plug pocket. These however usually result misfiring and fuel burning in exhaust pipe too.

Petteri

[permit]

It was misty/foggy when this happened to me too. It would be weird if this were related.