1987 GL10 single port fuel injected
55K original miles
I changed the MAF sensor a few days ago (due to non starting). When I got the car started I noticed it was idling rough and even stalled when I put it in gear. So I pulled all the plug wires one at a time (engine running) and when I pull cylinders 2,3 and 4 the engine runs worse. But when I pull #1 wire the engine has no change. So I changed the #1 plug, wires, distributor cap and rotor and pulled #1... still dead. I took the #1 wire off, put the old plug in the end of the wire and ran a jumper wire from the old plug to the new plug (still in the engine) and the old plug (exposed) fires the plug consistantly.
I took the new plug out of the engine and the cylinder has good compression... Which tells me there is fuel issue, but with the single point fuel injection why would it feed all the cylinders except #1????
When in park it idles around 700-800 rpm. In drive it idles around 500-600.
Any ideas why the #1 cylinder is not firing or why the engine is suddonly running rough?