Engine won't rev

[achillies]

Hi all....I am new to E30s and have an 84 318i. It starts/idles and generally runs fine When I 1st got it it didnt seem to want to rev above 4300-4500. The owner said it needed a throttle cable and he was right...cable was almost so long that it barely had any pull on the TB. I replaced the cable and it seem to be correct but when I drive the car it still seems to go "flat" or run out of revs at about 4500. When my wife steps on the gas it seems to pull the throttle lever all the way. Any suggestions? Thanks for the help with my 1st BMW.

[dj01540i6sp]

Hello achillies - This could be a number of things it starts and idles good? so a vacuum leak might not be but when rubber lines warms up they can get loose and take an effect. Check vacuum lines for good snug fit connections. - Have you checked the catalytic converter it could be clogging up this happens when greater exhaust is forced into the pipe forcing pieces to lodge against the exit pipe and it makes an engine bog down/no power. Can you here loose particles in it when shaking it? - It also could be gas starvation ''fuel filter'' wont let enough gas through fast enough for the higher Revs'. - Possible throttle position sensor bad.
Good Luck and keep us informed when you do fined the problem so we all can learn.

[Zachary]

your tacho is out

[achillies]

It is interesting you say that because when the car is cold (cool) it all seems fine. The indicated RPMs match up with a speed/rpm chart and the car revs to redline. But after everything gets hot the tach starts showing RPMs that are at least 800-900 RPM different (too low). It also seems to hit the rev limiter at 4300. Is there any way to check the tach? Anyone that can repair the cluster? Thanks

[transatlantic0207]

Just remove the cluster and replace the tach....I am not sure how high your car revs to but you may be able to switch to a tach from an I. All you need in the tach which removes easy from the cluster.

[achillies]

I hooked up an external tach and the car says 4300 but the external tach reads 6100. The error starts at 100 RPM at idle and goes to 2000 RPM at redline. So it seems the car runs ok but the tach or wiring is bad. I guess that is good news but now I need to chase an electrical problem. Do I just send the cluster out or do I attempt to find the problem in the wiring. The Gas/Temp seems to be ok and the speedo seems ok except when I depres the clutch all the way to the floor...the speedo quits but restarts when I slightly let out the clutch (1/2 inch). Any suggestions about the tachometer?

Can the tach be bought seperatly or am I better off sendint the whole cluster out for repair? Thanks