Bug runs rough when hot

Any idea what causes my '73, 1600 dual port to lose power and run really rough if I drive it too far?

Thanks! Earl

Reply to
Earl Brown
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coil heating up and failing? spark plug wires heating up and failing?

Reply to
jboothbee

Make sure the manifold boots aren't cracked and leaking air.

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Reply to
Funkie

Any recommendations for brands to replace with, if this is what it is?

Reply to
Earl Brown

I'll look at that. Would that be an only-when-it's-hot thing?

Reply to
Earl Brown

replacing plug wires is part of cheap tuneup, I don't know what brands are good, but if you just get a cheap set, you can at least eliminate one possibility of the source of your problems.

I would check all ignition parts. get a good coil, good wires, cap and rotor for distributor, drive it and see if it runs any better.

are you running points?

Rich

Reply to
aiiadict

How far do you have to drive it before it starts running rough?

Reply to
Mike64Bug

Good tune up which should include: Retorque cylinder heads (lower nuts are usually the ones that get loose) Adjust valves new plugs, points, cap rotor and wires, and change/service all filters and oil. Check for intake manifold leaks.

Bad gas or weak fuel pressure?

Been too long since I have worked on one of these. lol later, dave (One out of many daves)

Reply to
dave AKA vwdoc1

Time to do a compression check. How old is the engine? #3 cylinder dropped valve seat or cracks. Just my guess. When hot is the clue... Probably does not want to start until it cools off again. Probably runs smooth at higher rpm but barely idles. If you need to start it when hot and it won't, roll it down a hill and compression start it - probably takes right off at higher rpm. If all these items are true, it is because the crack in the head opens up when hot and closes back down when cold. If all these items are not true, then it likely is not a cracked head. Put a vacuum gauge on it when it's running rough and see if the needle pulses dramatically. If so it drops on dead cylinder. - BaH

Reply to
Busahaulic

Thanks for the info. It'll probably be a while before I can look into it - it spit out a spark plug the other day, and it happens to be a rough-budget time. I've got to save up before I can afford the work (and the wife doesn't trust me to get it right, since tapping for a sleeve didn't work...)

But maybe cracked head is why the spark plug flew...

Earl

Reply to
Earl Brown

Well you could try to "glue" the spark plug into the head with JB Weld if all else has failed. Since you are probably talking another head anyway, the weld might last you awhile until you find the right person to work on it and of course the funds! ;-)

The best fix, of course, is fixing it right with new cylinder heads. JMHO later, dave (One out of many daves)

Reply to
dave AKA vwdoc1

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