When timing is everything...

Dear Car Talk

Dear Car Talk | May 01, 1990

Dear Tom and Ray:

I own a 1979 Ford 150 Pick up. I have an intermittent problem that has mystified several good mechanics. Sometimes after starting my truck, driving three miles to town, and turning it off, it refuses to re-start. It sounds as though the battery is dead. Sometimes it starts after waiting a few minutes. I have replaced the starter and the battery. Any other ideas?

TOM: Timing is everything, Lewis. Well, almost everything. If your timing is too advanced, it could make the truck hard to start when it's warm.

RAY: It's also likely that severe carbon buildup is compounding the problem. Since this heap is still on the road after 11 years, I'm going to assume that you don't do much highway driving. In stop and go driving, carbon builds up on the piston crowns. The carbon heats up during those first three miles. Then, when you try to restart the truck a few minutes later, the super heated carbon causes early ignition.

TOM: You have two choices, Lewis. You can try to de-carbonize the piston crowns. There are gasoline additives that claim to do this, or you can take off the head and physically remove the carbon buildup (like a cleaning at the dentist). The other option is to just leave the engine running when you're in town. If the truck's still there when you come out, you have no problem because it's already running. If it's been stolen, you know the thieves won't go more than one stop.

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