Stumbling, Stuttering, Slow Starting!

For the past few months I have noticed that my little 68' Bug has had a hard time starting. Not initially (which is odd), but after a long drive - and by long drive I mean a couple of hours - I have a hard time re-starting the engine. So I would stop for gas, pump, pay, and when I go to start the car - silence. Since I am generally alone, I can't "hear" the starter taking hold, but it doesn't seem to be moving back there. My battery seems fine. My generator delivers just under 14 volts. And ... if I WAIT a few minutes ... it starts just fine.

So ... is that a coil going bad? Here may be another clue, or an unrelated problem.

I was driving back from Maryland (to Ohio) a few nights ago and about

300 miles into the journey it felt like I was getting struck by heavy wind. But, it was my engine. It seemed to be missing a beat. It stumbled, it caught up, and then stumbled again. At first, I thought my engine was having a melt down so I jerked off the road and went back to check my oil. It was a *little* low (about half a quart). But that wasn't the problem. It may have just been hot, or so I thought. So I let it take a breater and cool off. Once I was back on the road it seemed to be fine. But about 10 minutes later it started up again. Stumbling, and stuttering. Odd.

It seemed to happen more when I pushed it past 60 Mph. If I slowed down a bit to say, 50 Mph, it would resume normal operation.

So is this another sign of a bad coil? Or do I need to do a compression test? :-(

Thanks everyone.

-Steve Ballantyne

Reply to
steve.ballantyne
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"I can't "hear" the starter taking hold,"

If the starter doesn't crank when you turn the key BUT the OIL/GEN lights come on normally, then it's not the Coil, or the battery or the battery cables, etc. It almost *has* to be the Ignition switch.

It's a common problem.

Fix yourself up with a 3-foot length of wire. Next time it won't crank, do this: Lift rear seat. On left side, look for plastic splice with 2 Red wires. Jumper that splice with your wire to the battery (+) post. (Shift in NEUTRAL!) If it cranks now, the Ignition switch is bad. (You can start the engine this way by leaving the key On.)

Yes, it *could* be other things like a loose terminal on the starter or intermittent solenoid, etc. Blah,blah..... But if you do this test *first*, you'll know for sure.

------------------ The stumbling above 60MPH may be harder to pinpoint. But it's NOT horrid things like bad compression.

It *could* be fuel starvation due to bad pump or clogged screen in tank. Or clogged fuel line or aftermarket filter. On a '68 it's probably not tank venting problem, but maybe......

It could also be Ignition-related. Coil breaking down as engine heats up. Ditto for condensor. Even dumb things like a push-on connector becoming poor contact as it warms up. OR......the Ignition switch.

I don't know how much you are equipped to underatke in checking, but those are the things I would start with.

Speedy Jim

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Reply to
Speedy Jim

Hey Jim,

These are great things for me to check out. Poor contact from a push on connector is a VERY good possibility. I need to get this sucker on jacks and spend half a day underneath of it cleaning up my connectors and possibly crimping on new ones to some fresh copper.

I am seeing that the coil is less than $20 (for a Bosch) so I might as well just replace that anyhow and see if it works. The old one is ... very old. It's been painted over, and it looks like it's one with the fan shrouding.

Also, something cheap I didn't think about ... could this be a worn set of points? I have never replaced them (owned the car for a couple years). My wires, and cap are all new (a month or two old).

Thanks!

-Steve Ballantyne

68 Bug
Reply to
steve.ballantyne

Points/condensor possible. Might as well replace. While you're in there, inspect the little braided flex pigtail, lead. If broken, spark will be intermittent.

Speedy Jim

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Reply to
Speedy Jim

....might try a Pertronix ignition.

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Rob and Dave's

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Reply to
Jim347a

Maybe I have been barking up the wrong tree. Could all this be caused by a beaten distributor cap? I popped it off to have a look at my points, and there are thick black lines (about an eigth of an inch high) that strike through each terminal in the "sweet spot" where the rotor passes.

I replaced my cap about 5 months ago, but I have put quite a few miles on it since then. So, that needs replaced regardless, and would probably fix my issues. But! .. When I replaced my old cap, the center terminal "thingie" (whatever you call it) that comes down from the coil wire was worn completely FLAT! As if, that cap saw every good mile of it's life, and the terminals were shining like a new penny.

So what would cause it to die this way? Logic tells me that I must have moisture in there that caused the burning apearance. Or, would a bad condenser cause this abuse?

So far on my part list I am thinking:

a) Cap b) Condenser c) Points (have never been replaced in the 3 years or so that I have driven it)

Is this a good list? I am thinking, it was never a coil issue (thanks to the advice of you all).

-Steve Ballantyne

68' Bug
Reply to
steve.ballantyne

Won't hurt to replace the things on your list.

It's normal for the cap "contacts" to be burned. And, it doesn't matter; the hi voltage will leap over the small space easily.

Speedy Jim

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Reply to
Speedy Jim

Before doing the "replace everything" mode - You have checked the point gap? and check your rotor, especially if it is the "resister" type see here

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Grahame from Aus

Reply to
Grahame Rumballe

I replaced the coil, condenser, and points (and of course adjusted the points). But after a road test, I was back in the same boat. So none of that was a problem, but probably needed replaced sooner or later anyhow. I also checked the rotor with my multi-meter, and it seems to be working just fine.

My fuel filter was a bit dirty, so I replaced that along with the other parts. And I also climbed up underneath and cleaned up my ignition, and solenoid/starter contacts.

Before I had said that it was not running hot, but perhaps I was wrong. Today when it started to slump and lose power, I pulled off an opened up the cabinet. It was pretty warm in the cabinet and when I uncapped the 'OEL' cap, I got a puff of smoke. The engine was hot to the touch, as was the dip stick.

As per the Muir book I stuck my hand into the fan and felt around for any debris - came up with none. The other suggestion for a hot engine is to check the valves (which I have not done in a while, and it's surely do for a tuning).

I seem to also remember reading about problems with "flaps" although I can't seem to find any mention of them in the Muir book. Is there a possibility of blocked air flow in the shroud from flaps not opening?

-Steve Ballantyne

Reply to
steve.ballantyne

See Jan's page on flaps:

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You really need to measure the oil gtemp to find out if it is overheating or not. Don't trust Muir's "too-hot-to-hold" test on the dipstick. If you can find a cooking/candy thermometer with a long stem that will fit in the dipstick hole, this makes a quick and easy way to measure. Oil temps at hiway speed can run as high as 230F , depending on lots of factors.

Speedy Jim

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Reply to
Speedy Jim

\

Quite by coincidence, I was browsing eBay and came across a number of inexpensive digital thermometers with hi-temp probes:

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this seller has a selection of various types for lab use:
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Some have Alarms you can set for a specific temp. There are even radio freq remote readouts so you don't have to run any wires.

Speedy Jim

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Reply to
Speedy Jim

Well folks ... I have news!

After doing some more reading, I thought a valve adjustment might be in order. It's easy enough and I thought it might provide some clues. What I found from that job is that #1 and #3 were a bit tight on the exhaust (I could get the .004 feeler in -but not the .006) but the intake valves were right on. #2 and #4 needed no adjustments.

After the adjustment I started her up and let her warm up, which didn't take long. Pretty soon it was running hot again so I shut it down. Next, I removed the spark plugs. #1 and #3 had had turned bright white on the contacts. #2 and #4 were just blackened in the usual way (not really burnt, just a little worn). But what does the white mean? Something bad I'm sure.

I have never performed a compression test before, but it didn't seem too tough. Using a really cheap compression tester that I inherited from my grandfather, I got the following ...

#1 - 105 pounds of pressure #2 - 100 pounds of pressure #3 - 125-135 and up! #4 - ???

With number four, I couldn't get the tester down into the pit of the threading. This compression tester was one solid peice, and I couldn't twist it around the intake manifold. At one point I picked up a blast of 30 pounds, and then I lost it. I might be in the spot, and I am just not getting any compression at all (I can feel and see strong puffs, but I can't get the meter to jump, and I don't 'feel' the pumps) ... but more likely I need a tester with a flexible tube between the gauge and the nozzle thingie.

With number three, I was getting higher compression with each cycle. I know that's not good. From what I understand, this is caused by a stuck valve. Since the pressure never escapes through the exhaust, the blasts keep getting stronger. Am I right on this?

At any rate, I think I have issues. This may be the last ride I take for a while. I was thinking perhaps I could put the spark plugs back in and run the engine with the valve covers off to watch and see if the valves are noticeably stuck. But ... maybe that's a stupid idea.

Those of you with some experience in this are and surely give me some clues. ;-)

Thanks!

-Steve Ballantyne

Reply to
steve.ballantyne

LOL Jim....just came from the home improvement group, eh?

Reply to
Joey Tribiani

Say what?

That's some link there :)

Try this instead:

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I need to re-write the page some day but the essential info is there and it's correct.

Jan

Reply to
Jan

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