e30 325IS cutting out?

[saad]

Hi people,

would like to no if anyone has heard of or experianced a problem where their e30 325is is cutting out at appx 4500rpm for a second then comes back on again while driving. Note this only happens in second to fith gear onwards and only when driving with your foot down!

Any help is kindly appreciated

[mrLEE30]

and to translate as not everyonre knows the abbreviations!!! : Throttle Position Sensor, and Wide Open Throttle

failing that try the DME relay (Digital Motor Electronics)

[tari]

I've been having the same prob with my 325. When it cuts out, the ABS light comes on and goes out. How would you test the TPS and the WOT..

[mrLEE30]

to test the TPS is quite easy if you have a multimeter.

remove the inlet boot from the throttle body / Air Flow meter.

you will see a plug at the base of the inlet hole, remove this plug and it will reveal three pins. set you meter to read volts DC (DCV or sometimes DC--) measure the femail portion of the connection, you should have about 5V between the inner and each outer pin (with ingition on!)

now set your meter to read resistance or Ohms (Ω). test it works by connection the two measureing leads together, you should read 0Ω - some analogue meters can be adjusted at this point.

now look into the inlet body and the pins from left to right i will call 1 2 3 (so 1 is toward the radiator) connect the leads to pin 1 and pin 2 it should now read 0Ω, noe slowly open the throttle and this should change to open circuit or a high resistance almost immediately as you begin to move the throttle (its supposed to move about .5mm) you need to check it only reads 0Ω when closed and at all other points up to full throttle it should read high or infinite resistance - move it slowly and look for any changes in the readings as you move from closed to fully open and back to closed. now connect to pins 2 and 3 it should read high reisistance, now slowly open the throttle it should not change until you reach about 10Degrees of fully open where at this point the resistance should be 0Ω and stay 0Ω up to fully opened throttle. If you have anything else then there is a problem, if not dont touch it, it can be adjusted but only if needed.

Tari, in your case it seems like a loss of power to the ECU (hence the ABS light comming on), inspect the earth connection at the battery and alternator, and look to see if the DME relay is loose (its found in the cover next to the Air flow meter, you will see three relays (or place for three relays - you may only have two. the one closest to the radiator is the DME relay and check this one (or replace it) the middle one is the fuel pump relay and the one closest to the driver is the relay for the oxygen sensor heater.

and Willnz you can be forgiven this time

mrlee.....

[tari]

Thanks MrLee!!

Ill give it a go in the morning.

[saad]

thanks guys.

will lwt you know of the progress

[saad]

no everything keeps working.

very weird

the engine literally cuts out for a second-usally in 2nd or 3rd gear at appx 4500rpm (peak torque?), then will pull through back to redline

in the longer gears (usally 4th and 5th) it gets to 4500 drops out for a second, grabs again, gets back to 4500, drops out again, and son on, it wont get past it and will keep cutting out and climbing back to about that rpm...very frustrating!!

[saad]

no, it only happens when it is underload, not when free reving it.

I am quite sure that the guy who owned it before me has installed an ecu powerchip in it. Do you think that a faulty chip could cause the problem?

Thanks again for this help

[saad]

Thanks again for the advice.

Just a quck question. Is it normal for the cars idle to be a bit unsteady after the removing the cars battery for a few hours?

Im guessing this is because the ecu chips memory gets wiped when the battery is disconnected and so it has to re-adjust??