I staged that shot as a little contest to see who’d notice. We have a winner! Your prize is a case of 100 copies of “Frampton Comes Alive” on vinyl, generously donated by Al’s Vintage Records in Passaic, New Jersey. Sorry, no shipping, so you’ll have to pick them up in person.

The car is a 1966 Corvair Corsa. Two beauties side by side…

 

Karl, I thought it might be a Corvair! I also had a 66 Corvair Corsa but in a darker blue, it was my first car. I removed the 4 one barrel carbs and installed a Holley 4 barrel with chrome runners coming off of it. Mine was a 4 speed. I learned some of my early mechanical skills on that one, like trying to keep the fan belt on at a 90°angle!

 

Cautiously optimistic I got it. Went for a short test drive and the symptoms are much improved. Got it to chug once, but nothing like it had been doing. May be part of the relearn after having the battery disconnected. Idle is much more stable. No codes, but it may not have been a long enough drive for that.

Also found the PCV valve nearly clogged. More details on that when I’m not nodding off in my comfy chair by the wood stove.

Will go for breakfast a longer test drive tomorrow to be sure.

 

Excellent. I think you are right about relearn. The old girl had at least one foot in the grave. You are doing great dr karlstein

 

I NEVER want to hear anybody insist a part must be good because it's brand new. I think I can finally wrap up this sordid tale with an important caution about new parts bad from stock.

Way back when, my '02 V6 had a nasty oil leak from the RH valve cover onto the exhaust manifold. I was also getting a light stumble at partial throttle settings, and an occasional P0301 misfire code. No problem, I thought. I'll pull that big intake plenum, replace the valve cover gaskets, and install 6 new coils and plugs while I was at it. My primary concern was fixing the oil leak, as the stumble was very light and the code only showed up once or twice a month.

The oil leak was cured, but the stumble became worse. Go back to the start of this thread if you dare, but the primary cause of this new trouble was the new coil I installed in the #1 position. At the time, I considered the new coil could be bad, but what were the odds? On top of that, how unlucky could I be to install a bad coil in the same location that was previously acting up?

During the course of whining/moaning/troubleshooting, I fixed the following problems:

AC ripple higher than normal, reduced with a new battery. Still unknown what the limits are, but I ruled this out by disabling the alternator for a test drive.

Fuel pressure low. A mechanical gauge showed 32 PSI but the sensor showed the correct 40 PSI. A new sensor brought the actual fuel pressure within specs, but the stumble remained.

Fuel filter was nasty inside. No major improvement with new filter.

Found the PCV valve nearly clogged. At low throttle settings, normal airflow passes through the valve. Replacing it helped a bit, but the stumble continued.

Replaced the catalytic converter for that bank. I had previously replaced the other side, and had been putting off the second one. No joy.

A set of reman injectors was installed. I found the resistance of #2 injector out of whack compared to the other five, but it still drew the same amperage when bench tested. I thought the new injectors finally fixed the problem, but the stumble returned yesterday.

When I had the intake plenum off for the injectors, I swapped a known good coil and plug from the other bank into the suspect #1 position. No new codes for a while, but yesterday I suddenly got a P0306! Never had that one. I have never been so happy to get a fault code. The fault followed the bad coil I unknowingly installed about 2 months ago in the troublesome #1 cylinder. I installed a new coil (5 minute job on the LH bank) and immediately the idle smoothed out. I've since covered about 40 miles with no chugging and a nice smooth idle.

The moral of the story? Assume nothing. Suspect everything.

 

Great job, Karl!

What a diagnostic journey!

Can you tell us the brand of the "bad from new" coil so we can add it to the knowledge base?

Cheers,

Don

 

Please define "great". Sure seems like this thing kicked my a**. With 20/20 hindsight, shouldn't I have gone straight to the coil?




I got a full set of coils on eBay for $19. Are you implying that was a mistake?

All seriousness aside, I installed 3 Beck-Arnley coils and 3 Denso. The new one that failed was Beck-Arnley, which surprised me because I've had good results with their stuff on my Jag and other cars.

One slight concern literally kept me up last night. After swapping the suspect Beck-Arnley from #1 to #6 cylinder, and having the fault follow, I replaced it with a fourth Denso coil. I'm hoping the bad coil was just a fluke, and the remaining 2 Beck-Arnleys will remain satisfactory. Of course they are installed on the RH bank, the difficult side. Wish I had thought that one through a little better when I had the intake plenum off. Oh well, on the bright side, I'm now very good at pulling the plenum. 30 minutes tops.

Reminds me of an issue I had years ago with a different car. I had replaced the distributor cap and rotor as part of a tune-up, along with a bunch of other parts. The engine now ran poorly, and after revisiting all my recent work, I made my best guess of a bad distributor cap. Not thinking this through clearly enough (notice the trend?), I returned to the same store and got another cap. Turns out the replacement came from the same defective batch but that never crossed my mind. Only after tearing out my hair and trying just about everything else under the hood, I purchased another cap from a different source. Problem solved.

The moral of the story? Two parts:

1) My personal motto is to do as little as possible, for as long as it takes. That translates to do your work in small increments and test as you go, versus changing everything under the sun all in one fell swoop. That way, if something goes wrong, it's easy to know what caused it.

2) If new parts are suspected as defective, get a replacement from a different source.

 

I have had the very same problem on an XJ40. Distributor caps from the same source were both bad - third cap from a different source was good.

Cheers,

Don

 

This was an awesome read... thank you for sharing. Glad you figured this one out.