[ledzilla]

So, the last few times I've taken my wagon out, if the engine hasn't completely warmed up it would make a kind of pop from under the hood while accelerating. With each pop, there would a be a very brief loss of power. Not sure if it's related, but about the same time I started seeing the alternator light come on for a second or two while coming to a stop. In both cases, I was either accelerating to or decelerating from 55mph. Good old two-lane highway.

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[CatSkinner]

Could be pre-ignition or detonation. Here's a good article on it: Ask Away with Jeff Smith: What's the Difference Between Detonation and Pre-Ignition? - OnAllCylinders

 

[Bert]

Running lean causes that too. The choke may be out of adjustment.

 

[ledzilla]

Could be pre-ignition or detonation. Here's a good article on it: Ask Away with Jeff Smith: What's the Difference Between Detonation and Pre-Ignition? - OnAllCylinders

I know I have some mild issue with that. I recently acquired a timing light to get ignition timing set better. Running it on higher octane has alleviated it partially (only running 89 as opposed to 91+ because premium has gotten ridiculous). But I'm not certain this is the new issue.

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[ledzilla]

Running lean causes that too. The choke may be out of adjustment.

I think you might be right. I couldn't remember which way to adjust the choke pull off, in case it's part of the issue, and the first article I read (which didn't actually address what I was looking for) confirmed that if the choke is opening too soon and causing a lean condition while the engine is still warming up, it can cause popping/spitting out of the carb, which is what it feels like is happening.

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[R.S.LOGAN]

Running lean causes that too. The choke may be out of adjustment.

Or drawing air somewhere , perhaps vac hose , breather etc .

 

[ledzilla]

I have not yet had a proper combination of free time and sufficiently decent weather to look more into the issue. But because the car had been sitting, the other day I thought I ought to start it up amd run it for a while. Well, it won't start now. Just cranks. I took the air cleaner off, and I'm certain I could smell fuel, but the carburetor looks covered in carbon now. So, maybe the carb is sitting loose on the manifold now and losing a lot of vacuum? I'll be better able to check this weekend of the weather report is correct. Finally might get some warm dry weather while I'm actually home.

 

[R.S.LOGAN]

Worth pulling carb and checking the gasket .

 

[ledzilla]

The weather should be nice this weekend, so I'll take a look. I'll also check how tight the nuts are, too. A couple times on both of my carbed vehicles the carb had gotten loose and I had to tighten it down. It's rather annoying that they kept loosening like that. Given how the wagon's carb looks like it got covered in carbon, seems likely the carb is loose or has a bad gasket, and that carbon is a result of the popping.

 

[ledzilla]

Well, solved one problem. Since it's so very nice outside, figured I'd give it look over. The carb had two loose nuts, but it only took a quarter turn to secure them. Then I checked spark. There was no spark at all. Turns out the contacts on the coil got corroded. Cleaned them off and it started right up again. But I'll still probably need to take the time to examine the carb gaskets, see if they've gone bad after only a year.

 

[ledzilla]

Ok, so the popping seems to have stopped after I made an adjustment to the choke. Still wants to die on startup unless I press the gas pedal a little bit for a few seconds until the engine idle smooths out. But lucky me it seems to have developed an electrical problem suddenly that sucked the battery dry. Gotta figure out that mess, now.

 

[CatSkinner]

Was this an electric choke?

 

[ledzilla]

Sorry for the necro thread...

Was this an electric choke?

Well, I believe so, given that it has a bimetallic coil and an electrical connection.

And it looks like this could all very well be a vacuum leak. I haven't heard it until today. But I heard a hissing, and I found two derteriorated caps on the vacuum manifold along the firewall. Fortunately I had a couple spares and replaced them, but that didn't completely solve it. Also found that the cap for one of the two rear manifold vacuum ports is missing. I'm going to venture a guess that replacing that cap should go a long way to fixing this.

 

[R.S.LOGAN]

All these faults would be drawing air making it run too lean , your on the right track .

 

[ledzilla]

Guess I've let this sit for a while...

I have a battle plan of sorts. I disconnected and capped off some of the vacuum powered emissions parts. It has provided a noticeable improvement. Still not good enough to want to drive down the highway, though. So, once I have some warmer days where I'm not at work, I figure my best bet is to eliminate the rats nest of vacuum hoses. The plan is to only have lines to connect the EGR, choke pull-off, transmission, and the vacuum advance through one of the two thermal switches.

If that doesn't seem to be enough, I figure the next step is to block off the manifold vacuum port to remove the vacuum accessories. And yes, that includes the brake booster, but right not that doesn't matter. The booster is dead and no longer works, so it's already disconnected. I must say, it's not easy to stop that boat right now. If it turns out that something in the dash is leaking vacuum, I'm considering keeping the manifold port blocked off and installing an electric vacuum pump instead.