<VV> Engine Trouble

[Phil Fairman]

On May 18th, 2006,
Ray wrote:

   < I've got a condition with my vair that I could use some help with.  This is on the 66 500 coupe with the PG.  

     A few months ago (after sitting for a good few months without being driven) the car began misbehaving.  The engine would lose power, then surge, lose power, surge etc.  While doing this the engine would backfire through the exhaust.  The problem would come and go randomly, but got steadily worse.  While the car was acting up I found that the spark was errattic.  I replaced the wires, no change.  I then performed a tuneup at the distributor, no change.  

     At this point I took a gamble and replaced the coil with a brand new unit.  This seemed to fix the car, it ran fine afterward but I did notice just the slightest sign of the engine wavering on occasion.

     Fast Forward another month or two later, the original problem is back full force, and getting steadily worse again.  Timing and Dwell are right on, vacuum advance is working. 

I started the car, let it warm up.  Drove for about 5 minutes and it started to act up a little.  Misfired for about a minute then started running fine.  Another 5 minutes down the road the engine starts stuttering and backfiring, wont climb the next hill so I pull over.  Let the car sit for a minute and start it up, ran fine for the next hour and a half.  

     I was not able to catch it misbehaving to check the spark.  Runs fine anytime I try.

Also of note two additional things:

When sitting at a stop sign/light the idle occasionally just quits, no stumbling.... just quits suddenly.  I found the vacuum advance line was loose- this MIGHT be fixed.  

If you dont let the engine idle down for a few seconds when you stop before shutting off the engine it "diesels" (detonation, preignition) after shutting off the key pretty badly.  Lean mixture?  Temp light is not coming on.

I just ordered new carb filters and gaskets.  What ideas do you folks have?

Also note that this car sat for at least 5 years, maybe much more, before my purchasing it.  I'm at maybe 2,000 miles driven since I purchased the car.  Ran great at first, then problems started developing.  This is the same car that has the lifter tap, which I still haven't tracked down.>

Ray,

All the others have given fine suggestions, Lon's reply on the points plate is a good area.....Adding a Pertronix I with your existing points plate and your (I presume) 1.5 ohm coil should solve the problem as the Pertronix unit is far less sensitive to a worn plate than points are, just wire the Pertronix to a switched 12V source. 

Now, for something REALLY simple: All of your symptoms are highly indicative of a leaking/cracked, etc rubber hose in the fuel line. The hose is located where the body line from the tunnel joins the engine line in the left rear wheel well (Remove the wheel/tire and you'll see it)
This oft-neglected piece of hose is a source of leaks as it ages and cracks, intermittently allowing the fuel pump to suck air. While you are under there, checking and replacing, instead of just putting another piece of fuel line in add a WIX  #33032 or equivelent in-line fuel filter. This filter includes (4) corbin clamps (2) pieces of rubber fuel line and a metal-cased filter. I date and replace the filter every two years.....a couple of benefits: no more leaks in that portion of the line and an additional, very much (IMHO) needed filter that keeps crap, rust, etc from getting to those small valves in the fuel pump. If you do this and use the supplied corbin clamps, slightly flare the fuel line ends first, if you use "worm" clamps it's ok to use the lines un-flaired. It would also be prudent to replace the rubber fuel hose from the fuel sending unit that connects to the front of the body line, as this hose can do the same air leaking although, due to it's location, usually drips when it starts it's cracking thing. On any older car with questionable maintence history it's a good idea to replace ALL the vacuum hoses, including those that connect the crossover tube to the bases of the carbs. I am presuming that you are using a quality brass-contact dist cap and rotor and have a good set of ignition wires.

Hope this helps,

Phil Fairman
'66 Monza 110/PG