ignition problem

[trav87]

anyone have any ideas for my 87 chevy pick up? it's a 305 with a noticeable engine skip. changed plugs, wires, cap, rotor,and coil. good compression in all cylinders and good vacuum. think it's distributor related? I'm out of ideas. thanks

[a1supersport]

How often does this happen, and does it happen when it's cold, and/or after it's warmed up? Looks like you did all the right things. Only thing I can think of would be a weak valve spring, which would let the valve hang open when the rpm gets a little high.

[a1supersport]

By the way, when you changed all those parts, did you notice anything odd...like one or two fouled or discolored plugs? Did the cap and rotor have residue built up on only certain terminals? If you still have the old parts, check them out.

[a1supersport]

Thanks for the message . What kind of carb do you have? Do you have a fuel filter, and did you check it? Since you already did the ignition, and replaced the distributor, I'm guessing it may be the fuel system...specifically the carb. I wish I could hear it and see it...it'll be a whole lot easier to troubleshoot.

[RABarrett]

These engines are prone to eating cam lobes when provoked. You might try this... With the engine running, pull one wire at a time off of the dist cap, to locate the cylinder with the problem. Pull the plug wire off of the cap as this will be less likely to shock you. After locating the offending cylinder(s), do a running compression check. Pull the plug out of a known good cylinder, and with the engine running, check the compression. The needle will bounce between two numbers on the gauge. Note both of these numbers and then do the same on the bad one. Lower or more erratic readings may indicate a lobe issue. Ray