m3vs911

Hi, the car is driving lovely so far but recently I can hear some misfire from the back occasionally when I throttle it and start.

The sound will be gone after completely engaged of the clutch.

So I suspect it the belt is broken.
I also want to ask, what sort of problem will a broken distibutor belt gives?
will it tune down my car performance?
how bad ?

arthur

Rocket Rob

You don't want to drive the car with a broken distributor belt. You run the chance of misfire damaging something. If you remove the distributor caps, you can easily tell. The secondary rotor should turn with the primary. If you can turn it with your hand, then the belt is broken. If you must drive the car in that state, I would disconnect the coil module for that distributor cap so that you don't have spark firing at the wrong time. Let us know what you find.

crg53

It is NOT a good idea to drive the car with a broken dizzy belt. I would have it checked or do it yourself right away. It's easy to check, take off the secondary dizzy cap and see if you can turn the rotor by hand, if you can the belt is broken.



Edit: Rob, I was typing as you were posting.

ZG862

(...and it's pretty straightforward to change the belt if required. 2nd time around I reckon I could do it in about an hour.)

Z

m3vs911

thanks guys, any picture for reference?

Rocket Rob

Great minds think a like.

RW964

If I had to drive my car like that I would pull the rotor out and keep on going that way do not have to think about buring a piston I am not sure what happends when you do this and not disconnect the coil module for that distributor cap ..

abarthguy

I found an inexpensive spark tester at Kraegen that you hold next to a spark plug wire and it lights up if there is a spark.
Easy to tell if the second distributor is turning !

Indycam

Its faster / better to pull the connector to the ignition switch .
Reach in to where the coils are , pull down on the connector and that kills the spark completely , no arcs , no tracks , no problems .

m3vs911

thanks guys, but the misfire do not happen all the time, it just happens sometimes, does it mean the belt is worn out ?

Vandit

The belt is either broken or it's not broken.

Have you removed the distributor caps? What do the inside of the caps look like? How old are the rest of the ignition components?

ZG862

Try this thread https://rennlist.com/forums/964-foru...haft-gear.html

Checking for a broken belt requires only the removal of the 2 Philips screws on the secondary distributor (it's a pretty good idea to have the ignition off when you do this). As was said above, if you can turn the rotor arm around with your fingers then either the belt is broken or you're inhumanly strong and are moving the car by hand.

If the belt is broken and the arm has come to rest pointing at one plug you are going to be making that plug spark 3 times per engine RPM. This will not make the plug or wires last longer, improve your idle or make you more attractive to the opposite sex. On the other hand, if you find that you do have a broken belt, you can pull the wire from the coil whilst you wait for your new belt kit to turn up and contemplate the options for compressing the pinion back on to the shaft when you've finished the straightforward repair. Or of course you can take it to a garage and hand over your credit card.

,

Z