1974 2.0L - Rough Idle/low idle hunting Options

[frankc]

Hello,

I am working on a major resurrection of this 1974 914 2.0L.

I have completed changing /replacing the fuel system (lines, injectors, tank, etc), a major tune up and a reseal.

After a major tune, valve adjustment and timing - the car ran really well. I was very happy.

Started it today - to just hear it run - very rough idle when cold (this is new). It appeared to hunt between 300-700rpm - surge/die/surge/die/surge/die.

I have not touched the idle adjustment on the throttle body - it appeared to run at about 1000rpm when warm yesterday.

Cold Start Valve? AAR? Not sure where to look first. I will check the vacuum hoses again tonight.

Thanks,

Frank

[drewvw]

I unplugged the sensor on the front of throttle body

perhaps temp sensor was unplugged.....but I agree try to find the problem first before going that route. I just got done clamping down all my vacuum lines and it made a big difference.

[frankc]

Hi,

Too many meetings the past few days to get back to the site.

I will definitely recheck hoses for air leaks.

Stupid question - Where is the temp sensor for the heads located? I am not leaving anything to chance.

I did read the D-Jet bible and the AAR valve looks suspect. I live in North Carolina, so the cold start valve would not come into effect in 80 degree+ weather.

I believe I can check resistance and if necessary, check to see if it is stuck open or closed. I may have time tonight after everyone goes to bed.

Thanks everyone for their replies.

Frank

I unplugged the sensor on the front of throttle body

perhaps temp sensor was unplugged.....but I agree try to find the problem first before going that route. I just got done clamping down all my vacuum lines and it made a big difference.