Hey guys, having some carby issues with my car at the moment. Just wondering if there are any other carby's that are interchangable with the 4AC and if its worth it. Or just better to rebuild or grab a second hand one. Not really chasing power or anything. But wouldnt mind a little bit of extra go.

 

Cheers Brownie

They are to a certain extent - you need to change the base plate and a couple of small auxiliaries from your original carb...then just make sure you plug in the hoses in the right places, and you should be right!

 

That said, no extra go from the 4ac. rebuild would probably be a better alternative...

Edited September 12, 201214 yr by Bowler

Might want to double-check, you should have a 4AFC, not a 4AC. Can make quite a difference...

Whats the difference ?? The sticker on the Motor says 4ac?

 

Brownie

The "F" indicates a slave-gear driven twincam head. this is 16valve as opposed to a SOHC 8 valve 4ac unit. both are 1.6l. they run basically the same model carb however.

whats actaully wrong with it?

 

carby kits are cheap, new gaskets, float adjustment check, and a good clean should see it back up and running again?

I bought a whole new carb from ebay USA for the price of a rebuild kit.

Ok Maybe someone can shed some light on what is actually wrong. Basically, If I am just cruising along, highway, traffic etc makes no difference, The car will just stall. Tacho drops and it spit and splutters. Sometimes it comes back and drives fine, other times it spits and splutters till I stop, where the car will just die, I can sit and crank it and it spits splutters but starts again, Stinks like fuel and Coughs out some smoke. Then it will either run fine for a bit, or just die again. Seems to me as if its flooding itself. Fuel pump is working and its got fuel in the bowl when It dies. Any idea's ?

 

Brownie

the tacho cutting out immediatly points me to ignition problems, not carby.

I was thinking along the same lines, In saying that though, If its losing spark, why when it dies does it restart again? Why would it only lose spark for say 30 seconds and then come good again ? Why would it stink like fuel and cough some smoke when it re starts ?

well the smelling of fuel coughing of smoke could be all the unburnt fuel that isnt being ignited by the lack of spark.

 

As for why it starts up again I'm not sure, good point, not sure.

I have a new coil sitting in the glovebox, just sourced another carby. Might throw both on tonight and see the outcome. Hopefully good.

 

Brownie

If it is like my 4AC there is a bosch BIM 024 module under a cover on the side of the distributor. Exact same issue with mine. If you are driving and the engine is turning but no revs on the tacho = IGN problems... Coil and or module is my best guess

If the tacho doesn't drop to zero when the motor is still turning, then check the carby needle and seat.

 

A bit of dirt stuck in the needle housing will cause flooding and kill the motor with smoke and raw fuel smell, but the tacho will follow the revs down as it slows down with a dead engine. If the ignition system goes dead the tacho will go instantly to zero even if the car is turning the motor over.

Addicted is on to it. I replaced the module 6 months ago so I wasnted expecting it to be my problem again, But after replacing, carby, coil, fuel pump and filter, and spending hours on hours tracing vacum lines and wiring checking for a leak or short, I bit the bullet and got another module, Seems to be running fine now. Bought a spare while I was going So I have one in the glove box now!

 

Cheers Brownie