I've been working on my dad's X1/9 which has been parked for a good 15 years or so. After a lot of miscellaneous fixes and repairs we've got the car on the road and got to take it for a little cruise. Everything went fine until about two or three miles from home when we just lost all power. I managed to keep the car idling, but anytime I pressed the accelerator it choked and almost died. Managed to get it back home by fluttering the gas and keeping it in the lower gears. The next day we tried it again and had the same problem. It runs just fine and drives great until about two or three miles, once everything warms up it loses all power and just wants to die. We have fresh gas, a clean fuel filter, new lines from the fuel pump to engine, and we're both a little stumped. Does anyone have a suggestion or idea?
Technical '75 X1/9 Won't Run Once It's Warm
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Technical '75 X1/9 Won't Run Once It's Warm
jimbro1000
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If it idles ok then the problem is the fuelling, the idle mixture is ok but as soon as the choke comes off you are dependent on the main jets to get the fuelling right.
The first step is to clean the jets and emulsion tubes (only one at a time to avoid mixing them up) very thoroughly, you should also clean the tiny inline filter that lives inside the carb. A big dose of carb cleaner may help as well. Make sure the acceleration pump is working too (when you work the throttle by hand you should see a big squirt of fuel down the throat of the primary barrel). If this doesn't cure it then the float in the carburettor may have failed - this requires you to split the carb and take the top off. Odds are the gasket between the two parts will tear so make sure you have a replacement. Set the float at the correct level, make sure the needle valve in the top of the float chamber is moving freely and try again, if this doesn't work or you notice the float itself is full of fuel then you will need to replace the float.
If the idle is all over the place then it may be the ignition timing, when you increase the revs the ignition timing should advance. On european spec cars this is purely mechanical but on federal spec cars there is a vacuum advance as well just to make things more complicated. Get the timing checked at idle, it should be pretty much rock steady if not then either the vacuum isn't working or the mechanical advance has failed. I don't think it will be this as the car runs ok under choke but I've been wrong before...
The first step is to clean the jets and emulsion tubes (only one at a time to avoid mixing them up) very thoroughly, you should also clean the tiny inline filter that lives inside the carb. A big dose of carb cleaner may help as well. Make sure the acceleration pump is working too (when you work the throttle by hand you should see a big squirt of fuel down the throat of the primary barrel). If this doesn't cure it then the float in the carburettor may have failed - this requires you to split the carb and take the top off. Odds are the gasket between the two parts will tear so make sure you have a replacement. Set the float at the correct level, make sure the needle valve in the top of the float chamber is moving freely and try again, if this doesn't work or you notice the float itself is full of fuel then you will need to replace the float.
If the idle is all over the place then it may be the ignition timing, when you increase the revs the ignition timing should advance. On european spec cars this is purely mechanical but on federal spec cars there is a vacuum advance as well just to make things more complicated. Get the timing checked at idle, it should be pretty much rock steady if not then either the vacuum isn't working or the mechanical advance has failed. I don't think it will be this as the car runs ok under choke but I've been wrong before...
