Alright, i have a 1990 bird, LO3, TBI, 305. You know. Well, when i take off from a light, or from any standing stop, i hear a clunking, clanging sound coming from the engine. It mainly occurs during initial acceleration. However, it happens going uphill, and at high speeds. It also seems to get worse when the engine gets hotter. I've replaced the plugs, and plug wires. It has 160,000 miles on it. What's going on? And can it be fixed relatively cheaply? Also, my RPM never seems to exceed 3000, under half throttle. Is this normal? I Need Help! Thanks.

 

Sounds like yerbasic spark knock or "pinging"...

Try premium gas and see if it gets better.

Your timing may be advanced too far, which would be good for performance and gas mileage but will cause that other behavior, which is actually the air-fuel mixture in the cylinder igniting too soon and exploding instead of burning smoothly. In extreme cases it can cause engine damage or even destruction, so it's a good idea to get it taken care of.

As far as the RPM, if it goes up to the 4200-4500 range at full throttle, then that's about right. If it doesn't the throttle cable (which basically connects the trans to the throttle and tells the trans what the driver is trying to do) needs adjustment. That takes about 15 seconds to do.

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