Problems on Freeway in cold weather (SU Motor)

[Hugh 240z]

Where you at in SD? Way down south or something?

My car runs fine usually, so I don't have a problem driving it somewhere...

I will try the oil stuff first. Thank you guys for trying to help!

[e_racer1999]

clairemont... i'm not THAT great of a 240 mechanic, but hey, i could help! i doubt it would be worth the drive for me to look at it for you though..

[Gav240z]

I agree with Chris and Beandip sounds like a lean condition is causing the problem especially since you get backfire from the carbs. It also makes sense that it happens when it's cold outside because as you say cold air is denser making it run leaner. Fuel filter is another cheap fix but i will put my money on it being lean causing the problem.

[sblake01]

No one mentioned it and it may not be as crucial on carbed cars but what thermostat are you running?

[e_racer1999]

^^i was actually thinking about that last night

[Daniel]

Good point Sblake01- I used to change 190 winter 170 summer. I found my car liked the 190 always. Good call.

[Hugh 240z]

I was thinking about the thermostat as well.... I don't have any idea whats in there. It only takes a couple minutes to warm up, so I figure its not missing... but I should think about changing it out.