My Power Tour car is still not running right. HELP!

[Georgia_Model_A]

OK, so here is the deal. 28 Model A Ford with 350 Chev engine. Been on the road for years with no real issues. Got well into the Power Tour trip and it started to skip. The skip is like this. When cold, no skip. When at speed, no skip. The skip comes when it is at temp and you come to a stop and will continue until RPM are back up a bit.

I have replaced the dist cap, wires, plugs. No change.

Any ideas?

THANKS Mark [email protected]

[69SS 350 5 Speed]

HEI or points?

[Eliteman76]

Stupid thing...last year I was having a bit of a surge issue with my car, and turned out all this time, needed different springs and needles {edlebrock 600 performer}.
I was given some by the guys at the trailer in Bowling Green, and swapped them out last summer after the tour.
Made a difference. Still want to get a bigger carb, but I'm not a big carb guy, just enough to be dangerous. Sort of.

Any issues with coolant consumption, oil burning, anything odd?
I had a buddy with a 75 caddy fleetwood and ran great until a severe storm rolled though, and he splashed the engine with a lot of water. We replaced the coil, plugs, wires, rotor, but not the cap on the HEI.
Turned out the cap had a minute pin hole that was causing all the issues.

[Georgia_Model_A]

it has a Pertronics unit in it,

[69SS 350 5 Speed]

Uh Ohhh... That could be the issue. I had a problem in the Corvette after I put a Pertronics conversion in. It would not run right period. I needed a tach drive distributor and was getting ready to go back to a points set up when I found out that Summit was selling HEI's with a tach drive. The HEI did the trick for me. The only thing I had to do was replace the resistor wire with a AWG 12 wire and no more problems. The module could be going bad. On another train of thought are there any whistling noises? Maybe you have a vacuum leak somewhere.

[cstmwgn]

it has a Pertronics unit in it,

When we were removing the bad Pertronics unit from Cobra's car when it stopped on the road this year, one of the banshifters mentioned that grounds were extra critical with those units. I have no personal experience with them so I don't know if this is the standard every thing is caused by bad grounds car guy folklore or if it really is a specific issue for those units. You might want to verify that you have a good ground.

[cobra]

When we were removing the bad Pertronics unit from Cobra's car when it stopped on the road this year, one of the banshifters mentioned that grounds were extra critical with those units. I have no personal experience with them so I don't know if this is the standard every thing is caused by bad grounds car guy folklore or if it really is a specific issue for those units. You might want to verify that you have a good ground.

since George had to set the points by guesstimate, it ran good but not great. just set the points today with a feeler gauge, set the timing to it's right mark and now i can hook up the vacuem advance without it stalling.

[Georgia_Model_A]

Well it could be the Pertronics ....it is new but that does not mean it is good. I did install an extra ground when I installed the unit. It runs from the Pertronics mounting screw to the bolt that holds the coil mount. As for vacuum leaks....who knows, but I will check. Is there a way to test for vacuum leaks with a vacuum gauge? I have heard that you can spray WD40 on an engine to test for vacuum leaks............any idea of the details of this?

[BluLightning]

I've heard of spraying starting fluid and if the engine revs, you found your leak.

[oletrux4evr]

You can spray WD-40 around the intake seals and if it's leaking there it will suck it into the engine.....

[redragtop]

OK, so here is the deal. 28 Model A Ford with 350 Chev engine. Been on the road for years with no real issues. Got well into the Power Tour trip and it started to skip. The skip is like this. When cold, no skip. When at speed, no skip. The skip comes when it is at temp and you come to a stop and will continue until RPM are back up a bit.

I have replaced the dist cap, wires, plugs. No change.

Any ideas?

THANKS Mark [email protected]

Not sure what you mean by "skip". Do you mean cuts out/misses or non stable idle? Random or steady? Can you determine whether it is ignition or fuel related?

I personally have had very good results with pertronix conversions. They do "go bad"(as Bruce and others can attest), but so can all other types/brands of ignition components. Main thing with that conversion is to make sure you have full 12 volts to it with a good ground. You don't need as large of wire as a HEI, but still need full 12 volts. Your coil may need full 12 volts or a resistor to cut its voltage back (depends on type/brand of coil). Improper voltages/grounds can sometimes cause immediate failure or sometimes it takes a while so you will need to check and verify. As with most things, it would be a good idea to carry a spare module. If you installed it and problem goes away you will know the issue was with the old one. The only way to have a "known good part" is to have a used part which showed no signs of trouble.

As for checking for vacuum leaks, you need to spray around areas exposed to the intake vacuum. This is all areas between the throttle shafts and intake valves. Torn gasket, wore out bushing, porous material, etc. Spray carb or brake cleaner works well. You can use WD40 or something similar, but I don't like to because it will leave an oily residue which then needs/should be cleaned up. What ever you choose, you will be listening for a change in engine speed when the product is "sucked" into the leak and burned by the engine. Whether carbed or fuel injected, the engine wants all air to come through the carb or throttle body. As far as the engine is concerned, a vacuum leak is simply an uncontrolled air intrusion. The computer with fuel injection can just add more fuel to compensate for the "extra" air, but a carb can't and therefore runs rougher as the fuel mixture is leaned out.

Hope this helps
Mike

[69SS 350 5 Speed]

To add to Mike's info, I would stick with using brake cleaner to check for vacuum leaks. It doesn't leave any residue.

[cjcyclone]

Ok you have done the easy stuff, now the process of elimination, start with the vacuum leak test that is easy, I like using carb cleaner myself and don't go over board spraying it, if you have a spark somewhere you won't like it, but if you have a leak somewhere it will speed the engine up until it burns it out and then go back to the rough idle or skip, if you don't think you have a vacuum leak check the carb for a lean idle circuit, try closing the choke a little and see if it smothes out or gets worse, if it smothes out the carb is lean, it should get worse if the carb is correct because you are forceing more fuel in than it wants. if these things don't help get the trusty voltmeter out and start checking voltages and ground circuits, make sure those grounds are clean, a couple of years worth of running can cause problems(loose,dirty,rusty,etc), hopefully one of these areas will find your problem.

[67Cutlass]

OK, so here is the deal. 28 Model A Ford with 350 Chev engine. Been on the road for years with no real issues. Got well into the Power Tour trip and it started to skip. The skip is like this. When cold, no skip. When at speed, no skip. The skip comes when it is at temp and you come to a stop and will continue until RPM are back up a bit.

I have replaced the dist cap, wires, plugs. No change.

Any ideas?

THANKS Mark [email protected]

Hey Mark this is Eric, with the 67 Cutlass, that met up with you at Summit the day of the PT. If you haven't got this figured out yet, I've got an Accel HEI distributor that you can have. If I remember correctly it might be a tight fit near the firewall on your Model A.

Just let me know if you want it.

[Beagle]

the interesting thing for me about "water displacement formula 40" is that it does pretty good at that. If there is a moistore issue or sometimes a corrosion issue on the ignition, it will help it temporarily. Just as a test, I'd run a wire from your coil clamp back where you have it grounded back to the battery ground... if it helps, I'd check the engines ground wires to the chassis.