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EM Corvair running pretty rough
Posted by: 4wd430 ()
Date: June 19, 2017 01:54AM

Hello Everyone,

My 1960 Corvair has been running pretty rough as of late. It idles just fine, smooth without problems. When applying throttle the car begins to stumble a lot. The more the rpms climb and it gets closer to the powerglide shift point, the harder the stumbling. Due to this, the car barely accelerates at times and getting up to speed can be a challenge. A couple things to note:

1) Both carb accelerator pumps shoot out a nice stream (one isn't clogged or anything)

2) One of my exhaust manifolds (right side) has a bad seal due to the studs being worn out. The nuts can't tighten enough so exhaust escapes from the gap between the donut and the flange. Therefore, the car is pretty loud on this side. When the car is stumbling, I have a lot of backfiring/popping from here.

3) Carbs are balanced (I also have the idle turned up pretty high for now)

4) Car seems to get a little better after driving it for a while.

Thanks guys!

60' Corvair Deluxe 4dr



Edited 1 time(s). Last edit at 06/19/2017 01:55AM by 4wd430.

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Re: EM Corvair running pretty rough
Posted by: Brizo ()
Date: June 19, 2017 08:10AM

Have you checked the ignition points and dwell? The cheap points available in recent years have plastic rubbing blocks that tend to wear down quickly(or melt) if the breaker cam is dry. That is often how they will run if the points are just barely moving.

Dan Brizendine,
'64 8door Greenbrier 140 PG. "In beautiful Wanamaker Indiana...with one stop light and 5 pizza shops"

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Re: EM Corvair running pretty rough
Posted by: Wagon Master ()
Date: June 19, 2017 10:14AM

By your discription I would start by checking 3 things.
1. Insure the correct firing order of the plug wires at the dist. cap and spark plugs.
2. Check the dist. cap and rotor for cracks, defects and carbon tracking.
3. Do a valve adjustment using either the hot or cold method.


'64 Monza Coupe 140 4 speed
'61 700 Lakewood 95 4 speed
'69 Monza Convert. 140 Auto.

Been aircooled since 1973
Northwest Ohio

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Re: EM Corvair running pretty rough
Posted by: WCcorsa ()
Date: June 19, 2017 10:57AM

Compression test!

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Re: EM Corvair running pretty rough
Posted by: caroseiii ()
Date: June 19, 2017 12:25PM

Get new manifolds! Your car can't run well without exhaust packings.

Crawford

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Re: EM Corvair running pretty rough
Posted by: joelsplace ()
Date: June 19, 2017 12:36PM

Fix that exhaust leak. Don't replace the manifold just the studs. You may need a torch to remove the old studs. Don't break them off...

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Re: EM Corvair running pretty rough
Posted by: rowin4 ()
Date: June 19, 2017 04:22PM

Why don't you put in a new set of spark plugs.

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Re: EM Corvair running pretty rough
Posted by: Ratt643 ()
Date: June 19, 2017 04:35PM

All good suggestions. First, as recommended, fix your exhaust leak, so you can hear whats going on. Next, check the basics..points gap .016 for used points and .019 for new, if you are running points. Check the points for pitting or burning at the contacts. If they don't look good, replace the points and condenser as a set. Check the timing with a timing light, should be around 8 degrees, give or take a couple of degrees. If you have not replaced the distributor cap or the plug wires recently and they are old, then replace them. Also, as suggested, check the spark plugs. If they are black, then you have too much fuel pressure or the carburetor floats need to be dropped or the carbs need rebuilt.
It sounds like your problem is ignition related but check one last thing, make sure that your your charging system is putting out better than 12 volts. Please report back and let us know, good luck!


1964 Monza Coupe

Maryville, TN
U.S. 129 The"Tail Of The Dragon"

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Re: EM Corvair running pretty rough
Posted by: cwhunt ()
Date: June 19, 2017 06:40PM

My money would be on timing. When I first got my Corvair the timing was way off. I adjusted it accordingly and had major issues when trying to accelerate. Turns out my pressure retard (turbo engine) was stuck, so in the higher rpm range is was doing timing for idle speed. Replaced with a new repo advanced/retard from Clarks, reset timing and everything has been good since then.
Chris Hunt
San Diego, CA.
'63 Monza Spyder

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