Trying to sort out the *popping* in '83 SC

[gldnedge]

I'm looking at an '83 SC and would like to buy the car if this popping noise/sensation could be corrected. Here's what it does...

Under normal "around town" driving conditions the engine doesn't talk back at all. However, under hard throttle the car will pop and hessittatte twice between 4.5-6k.

The owner is trying to sort the problem out himself, but I would like to help him if I can. He has set the timing, changed the plugs, fiddled w/ the air-fuel mix and adjusted the valves. Nothing has changed. The car has 96K miles and still has the original plug wires that don't look very healthy, IMHO. Is it possible for the plug wires to cause the popping? Forgot to mention...he replaced the fuel filter as he thought it might be starving for gas.

This car has serious potential and the price is right. Anyone have ideas regarding the sputtering? If we could sort this problem out I'd probably buy the car...pending another compression leakdown test on #4 cylinder.

Thanks!

Aaron

[mede8er]

I still believe its starving for gas....

[gldnedge]

But wouldn't the car sputter at low rpm's under full throttle if it was starving for gas?

[mede8er]

From your account fuel supply at idle/launch seems to be sufficient.....but when my car cut out at higher RPM's it was a loose fuel pump relay.....

[sammyg2]

My SC did exactly the same thing when I bought it, bucked and hesitated under full throttle between 4500 and 5500 rpm.
I changed to magenecor wires (after changing alot of other parts with no improvement) and the hesitation went away.

[Groesbeck Hurricane]

Remember to PPI before you buy.

Is there any rattle at the lower RPMs??? Have you taken the lower valve covers off to check the headstuds?

Pressure test the fuel system to rule that out. Sam might also be onto something. I wonder if the fuel filter is starting to clog?

[stlrj]

It could be the spark plug connectors. Check the condition of the the rubber tips on the connectors that fit over the spark plug insulators. If any are broken, ripped or torn and not grabbing the spark plug insulator snug, this will cause the spark to track over the insulator instead of firing the plug at high load and rpm conditions.

-Joe