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Sun Sep 28, 2003 12:04 pm

I have noticed that my new engine has a problem every once in a while when accelerating. When I get to higher rpms or going up a hill or anytime underload it will pop for a second than pick back up if I am in 4th and going about 40 to 45 it will pop continuosly until I push the pedal alot and accelerate, this goes for any gear that is low in its range. I also notice that after I have been driving for a good while it gets worse ecspecially on hills I pulled the spark plugs and all of them except #3 look white. #3 has a gas smell as far as I can tell and is dark brownish color. I have a feeling this is the culprit. I have checked all my valves and they are dead on. Could this possibly be a bad spark plug wire causing misfire. What do you guys think. It almost seems like once it heats up there is a resistance problem with the wire causing this foul in the plug. I am just guessing though and am concerned. The engine only has 500 miles and runs beautifully for the most part.

Sun Sep 28, 2003 2:47 pm

Swap it with #4 and see what happens.

Sun Sep 28, 2003 3:03 pm

casey- I have been having the same exact problem with my '71 bus. Mine will start doing it after the car has been running for about 10 minutes or so, once the bus is warm. Same symptoms and conditions for the most part. My engine has been running super hot because of it or it's occuring because my engine is running hot. I haven't figured it out yet. Let me know if you get it handled and i'll do so likewise. Good luck

Sun Sep 28, 2003 9:32 pm

Cheap idea: Swap the #3 and #4 plug (not wire) and see if the condition is the same. If so, the problem is not the plug(s).
Then I would make sure that you are getting current through the plug wire to the #3. And check it hot.
If none of these things work, check the compression in #3 to make sure you have plenty enough. (I know 500 miles -- but you never know what might have happened.)
If none of this work, I would replace the rotor, cap and plug wires.
Best of luck!

Sun Sep 28, 2003 9:45 pm

If your plugs are WHITE, you're running too lean. This can be caused by a vacuum leak or by a faulty oxygen sensor (if so equipped), or also by a faulty temp sensor or malacjusted airflow meter. If your bus is running lean, which causes heat, it'll also run far better with advanced timing, which causes MORE heat and is a horrible idea. Make sure the basics- timing, dwell, etc., are OK before looking for major problems. Your one "bab" plug may have given up due to excess heat, or you may have a lean running problem overall compounded with a compression or ignition problem on the gas fouled cylinder. I'd do what others have suggested as far as testing the ignition/ electrical stuff, but again, I can't stress enough that if your plugs are white, you're too lean. Too lean is the number one cause of excess heat and premature engine failure!!!