Dodge 1976 pickup

Sounds like spark knock/detonation/pinging

Check the ignition timing and EGR

The timing is correct and I agree that it is probably spark knock just dont know why it is occuring. It is much worse in warm/hot weather also.

[quote:7e614e2a31="ctrice"]The timing is correct and I agree that it is probably spark knock just dont know why it is occuring. It is much worse in warm/hot weather also.[/quote:7e614e2a31]

You sure its not overheating-did you check the EGR it will cause detonation if its not opening-Knock sensor not retarding the timing

If the insulator is split or chipped, detonation (spark knock) may be occurring in the engine. The underlying cause here might be an inoperative EGR valve, overadvanced ignition timing, excessive compression due to accumulated deposits in the combustion chamber, or engine overheating.

I will check the EGR though I am not positive there is even one on this truck. It is 1976 and does not have a catalytic converter though it does have a charcoal canister. I heard pickups did not need emissions equipment until around 1979. I inherited it from my Grandfather who purchased it new. thank you for the advice.

[quote:61ccb123aa="ctrice"]I will check the EGR though I am not positive there is even one on this truck. It is 1976 and does not have a catalytic converter though it does have a charcoal canister. I heard pickups did not need emissions equipment until around 1979. I inherited it from my Grandfather who purchased it new. thank you for the advice.[/quote:61ccb123aa]

Do a wet and dry compression test and comeback with the results-if its higher than normal you got accumulated deposits in the combustion chamber-raising the compression to a point creating detonation

Pre-ignition and detonation is two different things

Will do. Thank you and I'll let you know what I find out.