Now what? Only running on 4 cylinders!

[Per Lindgren]

I just dont understand this. As I posted earlier, the car still ran on 4
after I had checked the plugs. So, the car just rested for 45 minutes
when Iposted a bit here, then I went outside to drive to the gas
station. Now it ran on 5 again. Nothing that indicated that I ever had a
problem. As Iain suggested I may have had some dirt in the fuel line, so
I will pour in some injector cleaner and soon a new fuel filter. I
wouldnt be surprised if the filter is the original from Sept. 1986.

PerL
87 Cq