E30 325i 5000 rpm rev limit

[Hawkenr]

Hi guys, recently bought a 325i Sport 1987 2door that has an irritating little proble, it cuts out at 5k rpm all the time, regardless of throttle position, in gear or neutral. It feels like a very electronic cut and not a misfire or hesitation. Until that point is pulls well.

Is there any obvious area to inspect first, a sensor, ECU etc. It has a K&N air filter on it and a scoprion exhaust., but surely this doesn't mean anything to the performance does it?

Please help.

Many thanks,

Richard (new to forum)

[kam-325i]

I would look at the rotor and dizzy cap.

[Hawkenr]

I would look at the rotor and dizzy cap.

Have renewed both, without the spring as well.

Would the ECU do this if it was getting a bad signal from somewhere?

[kam-325i]

It Might, But i think it would cause a problem all the way thru the rev range.
The ECU Gets signals from two place's regarding revs, The Sensor on the front pulley and from the pick up on spark plug lead one.

It might be worth looking at the front sensor, check for any crap on it or a poor fitting.

[Hawkenr]

It Might, But i think it would cause a problem all the way thru the rev range.
The ECU Gets signals from two place's regarding revs, The Sensor on the front pulley and from the pick up on spark plug lead one.

It might be worth looking at the front sensor, check for any crap on it or a poor fitting.

Will do many thanks.

[m-dtech]

if the sensors are not working the car wont start.

a problem i happen to have !

[Hawkenr]

appears to be 2 sensors on near side of engine near bellhousing. what do they do?

[m-dtech]

appears to be 2 sensors on near side of engine near bellhousing. what do they do?

earlier cars had the sensors on the gearbox. it was later moved to the front pully.

Personaly i think its Air or Fuel related. Or fault in ecu

[kam-325i]

appears to be 2 sensors on near side of engine near bellhousing. what do they do?

earlier cars had the sensors on the gearbox. it was later moved to the front pully.

Personaly i think its Air or Fuel related. Or fault in ecu

Missed the '87 bit !

aahhh, under fueling...... cloged fuel filtter ?

[Hawkenr]

appears to be 2 sensors on near side of engine near bellhousing. what do they do?

earlier cars had the sensors on the gearbox. it was later moved to the front pully.

Personaly i think its Air or Fuel related. Or fault in ecu

What should we look for on the air fuel side as is a neat cut and not a stutter or anything?

Thanks

[kam-325i]

Does it "Bounce" at the limit, ie hit 5000 then drop a bit, then back to 5000 and so on, like a normal rev limiter, or just stay at 5000 ?

[Hawkenr]

Does it "Bounce" at the limit, ie hit 5000 then drop a bit, then back to 5000 and so on, like a normal rev limiter, or just stay at 5000 ?

Definitely bounces, just like a regular rev limiter.

[johnono]

do u have an eta?

[m-dtech]

appears to be 2 sensors on near side of engine near bellhousing. what do they do?

earlier cars had the sensors on the gearbox. it was later moved to the front pully.

Personaly i think its Air or Fuel related. Or fault in ecu

What should we look for on the air fuel side as is a neat cut and not a stutter or anything?

Thanks

I think you should try another ECU then see if the problem persists.

[kam-325i]

do u have an eta?

That crossed my mind, someone fitted wrong ECU.
Was the limit on the ETA 5500 or 5700?

[Hawkenr]

do u have an eta?

Sorry whaty is an eta?

[kam-325i]

An ETA was BMW's economy version of the M20B25 engine, it was actually a 2.7, it had a lot more torque lower down the rev range, but had a low rev limit around the 5000 - 5500 mark.

[Hawkenr]

An ETA was BMW's economy version of the M20B25 engine, it was actually a 2.7, it had a lot more torque lower down the rev range, but had a low rev limit around the 5000 - 5500 mark.

V5 says 2494cc and thr red starts at 6500, so don't think we've got that one. Will try and find another ECU.

[johnono]

may well be an eta box.

do u have the bosch number on the ecu. we can tell u if its a regular or a eta ecu u have

[Hawkenr]

may well be an eta box.

do u have the bosch number on the ecu. we can tell u if its a regular or a eta ecu u have

Will get it an report back. What should it be in an 87 Sport?

[johnono]

dont ask me but an 87 may well be a jetronic

[Hawkenr]

dont ask me but an 87 may well be a jetronic

Nah, my quattro turb has K-Jet, this has EFI.

[johnono]

ok then

[Steviec]

Ive got a spare 325i ECU, if you want to try it, I can stick it in the post to ya, if it makes no odds, then just post it back. If it does fix it then you can have it for Ԛ£20.

Let me know.

[Hawkenr]

Ive got a spare 325i ECU, if you want to try it, I can stick it in the post to ya, if it makes no odds, then just post it back. If it does fix it then you can have it for Ԛ£20.

Let me know.

That would be great, but how do we know if it's the right one?

[m-dtech]

dont ask me but an 87 may well be a jetronic

if it was jettronic it would not have the two sensors on the gear box.

[Steviec]

Well it came as a spare for my 325i, the last owner couldnt get the car running right so they changed the ECU which turned out not to be the problem, so they left it with the car.

Im not too technically minded but your welcome to give it a go if you want.

[Hawkenr]

Well it came as a spare for my 325i, the last owner couldnt get the car running right so they changed the ECU which turned out not to be the problem, so they left it with the car.

Im not too technically minded but your welcome to give it a go if you want.

Brilliant. Can you please send to Richard Hawken, Steubing AG, 4th Floor, 86 Jermyn St, London, SW1Y 6JD.

Let me know postage cost etc.

Many thanks.

[Steviec]

Ill try to get it in the post tomorrow, dont worry about postage cost as ill send it through work.

[Hawkenr]

Ill try to get it in the post tomorrow, dont worry about postage cost as ill send it through work.

Cool thanks. Really appreciate your help.

[thesaint]

on my '86 325 the last 3 numbers on the ecu are 073.

[Steviec]

The ECU has gone in the post today and is being sent special delivery, so should be with you tomorrow.

[Hawkenr]

The ECU has gone in the post today and is being sent special delivery, so should be with you tomorrow.

Thanks a million, very kind. Will let you know what happens.

[Hawkenr]

The ECU has gone in the post today and is being sent special delivery, so should be with you tomorrow.

Thanks a million, very kind. Will let you know what happens.

Has arrived, many thanks for that. Will test it over the weekend and let you know the result.