I'm talking about my 1991 Plymouth Colt here. It has the 1.5L carbureted engine. One morning on the way to work I noticed a severe lack in power. The car would run, but the RPM would slow down at idle and the engine would buck pretty bad. During acceleration, it felt as though I had about 20hp and after revving the engine up and easing the clutch out it was still fairly hard to get the car moving.

So when I got home I did a compression test, and after turning the engine over for a about 2 seconds each test I found that the outer 2 cylinders had about 180 psi and the inner two had about 90 psi. Since the two cylinders with low compression are beside each other and making the same compression, it means I have a blown headgasket, right?

I'm not sure of the firing order, but I've been limping my car back and forth to work like this for the last week and it's not seeming to get any worse. I even adjusted the idle so that it idles at about 1500 rpm now and it doesn't buck around anymore. How long do you think I can drive like this? I've gotten used to the small power and adjusted my driving style accordingly, but I wondering how long it will most likely last and what kind of long term damage (if any) am I doing to it by driving it like this?

Thanks in advance.