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Draft Tube Switch to PCV Problem

J

jon0249

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After reviewing several posts on the draft tube elimination process and replacing it with a PCV valve, I thought I'd give it a try. I'm now having an issue that I can't seem to fix.

The hose from the PCV runs directly to the vacuum port on the intake. After 5 minutes of driving, the engine starts spitting and choking and dies. After a few minutes, it will start up again, and will idle without any problems. But after 3-5 minutes under a load (driving), it repeats the choking and dying.

On one occasion, right after it died, I took the hose off the intake and noticed a small amount of white smoke coming out of the port. Figuring the blow-by was righ in oil, I figured I would disconnect it and the oil would eventually burn off, with a little help from a few shots of gumout. So I took the hose off and plugged the vacuum line.

After disconnecting, I'm still having the problem. I can't imagine that there was that much oil getting in? Also, not getting much white smoke from the exhaust, so this is stumping me. Anybody have any similar problems with this PCV replacement for the draft tube?

Thanks,
Jon
 
Sounds like the condenser is on its way out if you are still using the points ignition......I had a similar problem and thats what it turned out to be......Once the heat got into the condenser it shorted out or something
 
Thanks for the advice - would have never thought about that. How would the heat get into the distributor, though? Oddly enough, just purchased an HEI dizzy that will do away with the condenser.
 
check the spark at the points, If the spark is orange the condenser is bad.Blue spark is a good thing.
Bobby
 
Replaced the condenser and everything was fine for about 10 minutes. Then the same problem, sputtering, coughing and eventually dying.

Could this be a fuel problem? It has most of the symptoms of running out of gas (tank is full). Hard to believe any of this is coincidental - afraid the PCV redirect is at the root of this. I've read/seen that most PVC lines are connected to the intake - is there harm in running the PCV line into the plenum just behind the air filter?

I'm fairly sure the PCV line is not related to the sputtering, so I welcome your ideas so I can stop pulling my hair out!
 
jon0249 said:
Replaced the condenser and everything was fine for about 10 minutes. Then the same problem, sputtering, coughing and eventually dying.

Could this be a fuel problem? It has most of the symptoms of running out of gas (tank is full). Hard to believe any of this is coincidental - afraid the PCV redirect is at the root of this. I've read/seen that most PVC lines are connected to the intake - is there harm in running the PCV line into the plenum just behind the air filter?

I'm fairly sure the PCV line is not related to the sputtering, so I welcome your ideas so I can stop pulling my hair out!
Click to expand...

How was your engine running before you started the conversion? I'm just wondering if you have a plugged exhaust system. If you put a vacuum gauge on the engine you should have 17-21 In. of vacuum on a stock engine and the needle should be smooth and steady if the reading is low and continues to get lower as the engine starts running bad then you could have a plugged exhaust system. You can also use the vacuum gauge to check your fuel presure, 4-5 PSI. is good. Then put the fuel hose in a coffee can and see how much volume of fuel you have while just cranking the engine over. I hope this helps....Big Tim :cool:
 
Thanks, Tim - will check this out if it comes to that.

Just got off the creeper - the rubber fuel hose between the tank outlet and steel line is collapsed - looks like I've been starving the engine for fuel. Not sure why it happened now, but I'll chase this one down and post results later. May have blown the fuel pump - slight smell of gas on the dipstick, but not sure if it was the gas on my hands...

To your question, was running fine before the PCV switcheroo, vacuum was stronbg although I didn't measure it.
 
Replaced fuel line and appears to have solved most of the problem. I suspect that there's something in the tank that was clogging up the collapsed hose, so my weekend now consists of removing the tank.
 
Coincidence is a strange thing...

I had some crap in the fuel tank that was clogging up at high speed (high rate of fuel flow). Also had a partially clogged idle pickup tube in the carb. At the same time the PCV switch was done, which is working perfectly now.

Never a dull moment.
 
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