327supreme

okay i got my plug wire situation tooken care of. i bought header plugs(just shorter plugs) and accel wires and looms that bolt to the valve cover and run the wires to keep it off the headers. so the car had been running fine even tho the number 6 cylinder was jumping fire bc of the wire. i didnt drive it but around the block after i replaced the first set of wires but like i said it ran strong for me then. so i got back home and saw that the boot was still touching the headers. so today i went and bought the shorter plugs and accel wires. i go to test drive it and now its backfiring through the carb.it wasnt doing this before i changed the plugs and wires. but i also adjusted the electric choke today to. i checked my firing order and its right. so could it be a bad cap and button or did i do something wrong when i adjusted the choke.

327supreme

also i forgot to mention that it runs fine in park or neutral even when you rev it up. but after you put a load on it and get to about 3000 rpm that its starts backfiring

J-(Chicago)

Try it with the distributor vacuum advance unplugged, and see what happens.

327supreme

i unplugged the vacuum advance and still the same. could that vacuum valve be stuck. i put a timing light on it and its right on time. put a new cap and button and still no chnage although it did drive fine for a little while after the new cap and then about 30 minutes after driving it it started again. the only two things i can think of is bad distributor or valves staying open but any help would be appreciated.

J-(Chicago)

It does not advance too much when you rev it up huh?
I was thinking theweights in the distributor were stuck, or advancing too quickly.
Hmmm..... I will have to think a little.

327supreme

i got the backfire to stop dont know how but its not doin it know more. but now my carb is poppin. so its running out of fuel i guess. im goin to try to adjust the mixture first before i change the jets and rods. but thanks j

oldsonharmont

I had this problem with a Buick 455 years ago... turned out to be a timing problem, eventually wound up replacing the timing chain. If you get flames in the carb from the back fire, just turn the key again and the carb will suck in the flame.

citcapp

Still sounds like timing. Did you rev the engine with the timing light connected and the vaccum connected to see if the timing advanced, If it doesn't then you vaccum advance is not working and needs to be repaired. A bad timing chain will have a similar effect.

88 coupe

Probably something to with the aftermarket parts you used on your Chev engine.

https://classicoldsmobile.com/forums/59737-post2.html

Members of a Chev forum will be more likely to be familiar with your "plug wire" problem and the way you went about "solving" it.

Norm

327supreme

if you really want to be technical about 88coupe theres no reason for me to go to a monte carlo forum either since the 327 was never put in a monte carlo

88 coupe

Nothing "technical" about it. Monte Carlo is a G body with a Chev engine. Is your "Supreme" a G body with a Chev engine?

Best place to go, to learn about a Chev engine in a G body.

Just tell them you have a problem with the 305 in your Monte Carlo.

Unlike those of us who have Olds engines in our G bodies, many of those Monte Carlo (G bodies with Chev engines) owners have experienced the same issues, and will have discovered the solutions you are looking for.

Norm

agtw31

take all that stuff you put on the car back off,and put the old stuff back on.

and dont ever open your hood again.