308 skipping and burning out sparkplug’s

I have a 77 308gt4 and in the last two weeks I have burned out two sets of spark plugs and now the car is skipping and backfiring under 3000 rpm and is slow when changing gears. Any one have an idea what is going on?

 

Sounds like it is running very lean. Is it running on both cylinder banks?

 

I think so it is burning out plugs on both sides.

 

Has anything been done or any part replaced since this problem started. Do you have points or an electronic ignition. Have you checked the timing and is it correct. Has anyone played with the carbs. Please go back to basics and think of what happened before this started. Also what plugs are you using. Did you get any bad fuel. Give us more details to work with. Can you post a picture of your plugs so we can see what they look like. Have you had a chance to do a compression check. Lets us know and we'll see what we can come up with.

 

Yes the water pump and the thermostat were replaced . It is running nice and cool now but this other issue has cropped up. I had the points checked yesterday and unless they slipped they were ok. I have not checked the timing. I used champion plugs but I do not have them here with me to take a photo. No one has played with the carbs that I know of. I have not done a compression check and the gas I purchased yesterday should have been fine. The car was running very hot until I got the cooling issue worked out.

 

I think we should see what the plugs look like. Are the tips white and melted or are they a gray color. And last are they black ar black and wet. Did the car run correctly before the waterpump change. What was the nature of the heat problem was it just a leaking WP ? How hot did the engine get with the WP issue. Are you still using both sets of points (R1 and R2) . Also are the distributor advances working correctly? When you warm up the car what is the watertemp when fully warmed up. Does it idle smoothly. Does it spit or pop at idle. As you push the accelerator at what rpm does it start to miss or break up. How many miles do you get before the plugs are bad. These carb motors are pretty straight forward so if it ran good before the WP replacement then something happened during the replacement. Has the retard switch on the front right carb been damaged or altered. You need to go through the basic checks. Timing check would be my 1st approach followed by a dwell check and a new set of NGK plugs (BP6ES or BP7ES (hotter)). Then you need to check dist. caps and wires and extenders. I think part of the key here is what the spark plugs look like. Keep going you'll get it.

 

check your plug extenders and also your ignition wire boots that the plug extenders go into. over time they will get porous and the spark will blow a hole through them and cause lots of missfire problems. You will actually see white burn holes through the boots..if the boots are shot you can just pull them off and slide some new rubber boots on (I have had this happen several times over the 13 years I've had my 78 gts) also, check your wires...generally, though, I have burned through 2 sets of boots to 1 set of wires...the extenders go but not quite at the same rate. If you can't find just the boots go to Pepboys/autozone etc and buy a cheap set of wires and pull the boots from them.