Just drove the Cortez from Austin to LA. Three long days. We advanced the timing for NM (4300ft) and backed it back off in SoCal. The Clark ran GREAT, until we got near LA. The change happened while driving:

It will not idle. Also has loss of power. It sounds like its not getting the right spark. Can keep it running with the throttle, but it "isn't right". Tried retiming it, it didn't help and I suspect I'm just compensating for another problem. Its getting fuel, it runs and will drive, but not settle down below 1100 or so. It runs roughs and there are small pertubations on the tachometer, that seem to match the roughness. Also the ammeter acts like there is a large load on it. I've checked all the wires, tried a new rotor, (it has electronic ignition). I'm guessing that it has something to do with the electrical, but I don't know.

Could a short somewhere else be pulling enough juice to make it run bad? I've been told that some ingition elements (electronic controller, coil) are a good/bad kind of thing and don't fail gradually. What about inside the distributor? The centrifugal and vacuum advances appear to be operational. What about the ballast resistor? I'm at a bit of a loss here. Any help much appreciated.

In route to Seattle;

zac

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polkayoureyeout.com

Sounds like a vacuum leak. But on the spark--have you pulled a plug and checked the spark? Is it a nice, big, bright blue spark or just a little, dull blue tick? To rule out the BR test the voltage going into and out of it (should be approx 13 V going in (running) and 8 V coming out)

Does the ampmeter get hot? All the cars ive seen that have ampmeters go bad run into some starnge electrical problems at the same time. Thank Ma for running the main power from the alt to the batt through the ampmeter.

Could also just be the idle screws need re-adjustment for altitude (or in LA...lack of air i.e. smog)

-Aaron

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The "Silver Bullet"
87 Ram D150

A vacuum leak is a good thing to check for. It could be that the carb mounting or intake manifold loosened up or the PCV is stuck open. A broken hose or popped-out vacuum plug will also do this.

Next would be the distributor, maybe the shaft has worn or is starting to seize up. Is the timming mark steady?

Try closing the choke flap a little at a time to see if the idle smooths out, this covers up a lean condition.
DD

I found a small vacuum leak on the base of the carb, and it seemed to help but not fix it. I get a large blue spark from the coil wire, but a plug seems to give a small spark. I'll try the distributor suggestions next. Its missing A LOT, so much that pulling a plug wire is barely noticeable.

Thanks for the help.

zac

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polkayoureyeout.com

Pulled the distributor, shaft ok, teeth intact (inside too!).

It runs best at high idle with the choke, almost evens out if I twiddle the flap to give it just a bit more air. As I step down the cam, it runs worse until it won't run at all on the low idle(!). I'm pretty much out of ideas, so I'm gonna do a compression test tomorrow.

zac

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polkayoureyeout.com

Make sure to check your throttle shaft for excessive play (vacuum leak) too - this can sneak up on you and seem like an "overnight" symptom.

Let me know if you need some Slant parts in LA. I have a few sources there I think I can hook you up with...

Good luck,

Lou

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Home of Slant6-powered fun machines since 1988

The magnetic thing inside the distributor sometimes goes bad and won't deliver much spark to the plugs. It'll run like it's out of time. Good luck.

Road trips are a lot of fun , I wish I was on one now. Tell us what kind of setup is in your cortez. What kind of carburetor , distributor (points or electronic ignition) and alternator is it equipted with ? It's hard to diagnose something with out being there. Others have made good suggestions. If your distributor bushings are going out it would idle rough and probably misfire if you had a points type distributor. Wiggle the distributor shaft with the rotor off and watch the point gap for excessive movement .Since it ran good over the mountains I would assume your piston rings ,timing chain and valves are in good working order. Therefore it is likely either in the fuel system or ignition system. I know you probably already Know this but we have to start some where. See how it runs with a full electrical load, turn on lights ,heater fan ,radio ect. If it misses more it might be your alternator or something in the charging system(low coil voltage at idle). Is your distributor cap and wires in good shape?Is the inside of your distributor oil soaked? A manifold vacuum gage and volt meter are good things to carry around in your toolbox for trouble shooting any old car. Like the others have said it's likely a vacuum leak or the distributor bushings. I would inspect the spark plugs ,if they are very white you definitely have a lean vacuum leak type of condition. This is very general and just off the top of my head . Good luck enjoy your trip!
D150

Thanks for all the suggestions. Its a '64 industrial /6 with a super six and 2bbl Carter BBD. Its got electronic ignition (chrysler I think), and two batteries on a solenoid-switched bus charged by a BIG old commercial "squirrel cage" alternator and a delco-remy voltage regulator. I've checked the distributor bushings, shaft and gears and it seems in order. The plugs are dusted black, but I think its a symptom, not a cause. There are also a FEW white spots. Not WHITE like its REALLY lean, but just spots. I did the valve lash before I left. I've got a vacuum gauge, but I've been using carb cleaner to check for leaks. I've got a volt meter, what should I look for at the coil? I'm gonna do a compression test and try the hall effect sensor in the distributor. Keep you posted.

zac

PS Who in LA has those good parts? Went 3 places yesterday before I found a suitable ROTOR, fer slant's sake!

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polkayoureyeout.com

I think I'd check the valve setting again. Pulling mountains with a heavy motorhome and a head that did not have hardened seats....

You can always find Slants in junkyards at Ecology Auto Wrecking in Santa Fe Springs, and at Pick Your Part in Sun Valley. The best parts store in the LA area is Allied Auto Supply on Colorado Blvd in Pasadena, CA (626) 793-1893. I think they have a new store somewhere else around LA too. They can get you just about anything within the day, and have lots in stock.

I also have a couple of personal sources, but I'd rather not give out #s unless you are in dire straits, or cannot find something specific. Wish I were still out there to help out.

Happy Hunting,

Lou

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Home of Slant6-powered fun machines since 1988

I think everybody here wishes they could be there to troubleshoot your engine problem, I know I do. I would measure your coil voltage while it is running on the positive lead on the coil.If this system uses an internal resistor coil you should have at least 12 volts going to the coil. If you have a ballast resistor you should have the same voltage going into that. The point I was trying to make is that maybe you have low alternator output at low rpm. This would cause rough idle at low rpm and lack of power.
If i was there I would check to see if vacuum advance is working with a timing light. Check electrical grounds on engine . Check distributer pickup coil gap. Things mentioned before like pcv valve and ballast resistor and pickup coil are real likely possibilities. Sometimes just swapping them out might not be a bad idea. I hope this helps.
D150

Actually, I just swapped out the coil, ballast resistor. I'm getting 14.2v off the alternator when its revved, but it won't idle, so I don't know there. Vacuum and mechanical advances are both working. The mark jumps when I rev it, I can suck the advance to work. The Hall effect thingy makes my Ohm meter jump, Plus its working, so I don't think thats it. Idle mix screws 2.5 turns out.

After doing the compression (120+ all the way across, should I do the valves anyway ?) I noticed that the plugs were again dusted in black, with a FEW little white spots. The spark looks OK so I thought I'd pursue the idea of vacuum leak. I checked all the hoses and nipples, nothing. I sprayed cleaner around all gaskets and fittings, and the top of the manifold. No luck. I pulled the manifold and replaced the gasket. No luck.

It run better with a little choke. Doc suggested this indicates a lean condition. That plus the white dots says he's right. What do I do about it? I checked the float level and check valves and blew out the passages, all clear.

Any new ideas? Thanks for sticking with me...

zac

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polkayoureyeout.com

If you have not adjusted the valves, I would recommend doing that, although it may be a long shot. Tight valves will cause poor idle and fouled plugs, but the cyl pressure should also drop, so that sounds unlikely since you checked that.

Your carb may just have something funky wrong inside. If you want to try a new one, there is a bang-up carb rebuilding place around LA, I think called Carburetor Exchange - nice work and affordable - they even do reliable and good Thermoquad rebuilds for $110! They have a branch in Pasadena, and I think one in Monrovia or Pomona (check yellow pages as there are more).

Another real possibility is that you skipped time, or your timing chain is stretched a bunch - this will definitely cause poor idle and power loss.

Hmmmm,

Lou

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Home of Slant6-powered fun machines since 1988

14+ Volts at the alternator is good. I mentioned 12 volts to the ballast resistor because some slant powered trucks have a resistance problem in the wiring( ammeter ,wiring harness ect.)and some times even when the battery is getting 14+ volts the ballast resistor may be getting less than 12 volts.
Some times things happen to vehicles that sit around a lot and are than driven. I guessing on this one but maybe you drove your gas tank a little lower than usual and sucked up some dirt from the bottom of the tank. Some of this junk may have migrated past your fuel filter and might be sitting in the bottom of the fuel bowl of the carb. I would disconnect your fuel filter and drain it on a clean rag to see if it picked up a lot of dirt and water. I wouldn't disassemble you carb just yet till you checked other things. Grab the body of the carb and see if it is loosening up from the base (vacuum leak). Sometimes the best way to get going again is to start replacing parts. I always carry a box of spare parts on long trips. This includes -water& fuel pumps ,carburetor,distributor ,fuel line ect. Good luck
D150