engine limiting when warm

Post Tue May 21, 2013 11:38 am

Hello everyone,
I have an 89 mtech2 325i sport.
Great car, but here's the problem:
When warm, the engine limits at 4.5k revs.
I replaced the fuel pump, engine thermostat, viscous fan.
Anybody got any ideas what this could be?
Thanks in advance

Post Tue May 21, 2013 12:05 pm

Check the Blue Temperature sensor:

http://www.e30zone.net/e30zonewiki/inde ... emp_Sensor

Also that the CPS is correctly positioned.

When was the cambelt last changed? If it is one tooth out, this may cause such a problem.

Post Wed May 22, 2013 11:36 am

Speedtouch wrote:Check the Blue Temperature sensor:

http://www.e30zone.net/e30zonewiki/inde ... emp_Sensor

Also that the CPS is correctly positioned.

When was the cambelt last changed? If it is one tooth out, this may cause such a problem.

Hello, thanks for your reply. The CPS was changed already. I don't know when the cam belt was changed last. I'll get onto that. Any other ideas?

Post Wed May 22, 2013 12:22 pm

Have you got the correct spark plugs fitted and are they gapped properly? Has the fuel filter been replaced? If it is several years old, it may be clogged, causing a restriction in the fuel flow; also check all the rubber fuel hoses for signs of deterioration - pinch them, and if they are too soft, replace them, as they may be narrowing and causing restriction.

Also check that the throttle is fully opening with the pedal pressed right down. If not, adjust the cable.

Which ECU are you running - the 0 261 200 173, or 380? May be worth trying another ECU.

Post Wed May 22, 2013 1:17 pm

Ive also experienced a faulty / cracked dizzy doing this

Post Wed May 22, 2013 5:11 pm

Speedtouch wrote:Have you got the correct spark plugs fitted and are they gapped properly? Has the fuel filter been replaced? If it is several years old, it may be clogged, causing a restriction in the fuel flow; also check all the rubber fuel hoses for signs of deterioration - pinch them, and if they are too soft, replace them, as they may be narrowing and causing restriction.

Also check that the throttle is fully opening with the pedal pressed right down. If not, adjust the cable.

Which ECU are you running - the 0 261 200 173, or 380? May be worth trying another ECU.

The correct spark plugs are fitted and they are gapped properly, i'm going to replace the fuel filter. The hoses seem fine; they are firm. The throttle is opening fully. The problem isn't there when the engine is cold.
aaaaaaaaaaggggggggghhhhhhhhhhhh!!!!!
This is my first e30 and i have lost the taste for it already. Got this car at christmas and have yet to drive it!!!
I don't know what ECu its running, I'll find out and get back to you.
Thanks for all your help so far.

Post Wed May 22, 2013 5:12 pm

Quaser wrote:Ive also experienced a faulty / cracked dizzy doing this

Thanks mate, it took me a while to work out what a dizzy is. Going to get the distributer off at the weekend and see what the story is.
Thanks again!!