General 1979 x1/9 bertone 1.5/5speed/californian model.

Currently reading:
General 1979 x1/9 bertone 1.5/5speed/californian model.


New member
Jan 10, 2006
los angeles
I've been browsing and it seems alot of us are having this issue. I just recently got a very good condition x1/9 bertone (1979 1.5 5 speed)

I did plenty of research (and i must say i'm a bit disappointed at the lack of good solid websites on the x1/9, but perhaps i'll fix that(sans this forum and a few others of course))and as such i was carefull to make sure it wasn't rusted or abused. all and all it seems to be in tip top shape minus some minor dents and dings.

anyhow, i drove the x home without a hitch and when i woke up the next day and took her for a spin, i noticed a rather rough idle, then followed by a lack of power, i would have to mash on the gas just to get her going and it just got worse.

it hardly turns on now and if it does its idle is sad and slow unless i press the gas down (at which it sounds fine) however when i shift into any gear the idle drops below 2k and the car hardly moves, if i shift back into nutrual it dies.
if i rev it shoots black smoke

now i already knew the car was running a tad bit rich just from the smell of it. but i'm pretty sure its the carb. and i'm most likely going to buy a new carb (i saw a pretty nifty one on's store) but, seeing as i know i'm getting another one, any suggestions on working this one out? (seeing as if i break it it wont matter much?)

so my questions are, is it the carb? what else could it be? what else should i change for sure to insure a happy x1/9? Any other adjustments/tune parts that'ed be good to double check?

btw i'm pretty handy with cars but i honestly haven't done much work on carbs (i've done much more with fi setups)
so any and all advice is valued.
The first problem is that you have all the worst of the smog control systems on your car which is something of a nightmare to anyone here. The worst we have to cope with is the sump breather feeding back into the air cleaner.

First place to look is the idle control speed and mixture settings. Idle speed is simply a nut/bolt assembly that stops the linkage arm returning too far. Idle mixture is normally adjusted by a small screw in the base of the carb (accessible from the rear of the carb as it sits in the car). Not sure about the federal spec but on the european ones there are a couple of plastic plugs in the boot that pop out and allow you to feed a screwdriver straight through into the recess. Tightening the screw will lean out the mixture, loosening it will enrich the mixture.

You need to check that all of your smog equipment is working as designed as well as this will mess with the setup too.