<VV> Groaning, Backfiring, Loss of Power

[kaczmarek at charter.net]

Steven
I will give my .02 to help you point the way.
> 
> From: "Steven J. Serenska" <corvair at serenska.com>
> Date: 2005/11/03 Thu PM 04:28:51 EST
> To: Virtual Vairs <virtualvairs at corvair.org>
> Subject: <VV> Groaning, Backfiring, Loss of Power
> 
> VVers:
> 
 This is a long post, but I'm trying to be detailed.  Here goes:
> 
>     1) On my annual summer drive up to Maine, at the end of 250-mile 
> long trip, the car seemed to be stuttering.  Unfortunately, it was late 
> at night and I just wanted to get there, so I wasn't paying as close 
> attention as I should have. 
> 
>     2) On the same trip, I parked the car for a few hours on a hill at a 
> very steep angle (with the nose upwards).  Afterward the car sputtered 
> again.   My fear at the time was that when I parked it that way, 
> whatever crud was in the tank might have washed back and clogged the 
> sock.  The problem disappeared on the long ride home.
> 
>     3) Near the end of the summer, I bought a tank of premium from a 
> very run down gas station in a bad part of town.  As it turned out, the 
> gas must have been pure varnish, because the car ran like a dog for the 
> entire tank (i.e., pinging like hell).  It also suffered from a 
> fantastic case of run-on every time I shut off the engine.
> 
>     4) You might recall that my fuel pump failed shortly thereafter.  As 
> it turns out, the cause might have been all the crud in the line and/or 
> the tank full of shellac I bought from the gas station.
> 
>     5) When I replaced the fuel pump, I took an air compressor and blew 
> through the lines back toward the tank.  Everything seemed clear.  I 
> knew that I was possibly blowing stuff back to the tank, but mostly I 
> wanted to ensure the lines were clear.
> 
>     6) This car has an inline filter and I replaced it when replaced the 
> fuel pump.  I noted that there was some condensation inside the filter, 
> so I also put in a bottle of drygas.  The car ran fine afterward.

You definitely have fuel issues. perhaps not the only problem.
Be methodical.

1.make sure carb filter stones are clear. If your're not using them, even if you have an in-line filter, you're wrong. 
2.Blow back all lines into tank. 
3.drop tank, drain fuel , remove sender assembly and check everything out. Remember, tanks rust from the inside out, rarely the other way round. Me thinks you will find the need to change filter sock, and replace or restore the tank. 

That would solve that one. 




     7) About two tankfuls later, the car began severely losing power and 
> making an awful groaning noise under acceleration.  The groaning isn't 
> to be confused with metal-on-metal grinding, it's just that the normally 
> smooth engine seemed like it was groaning under the strain.  About this 
> time, the engine also started backfiring like crazy.  The backfiring 
> didn't sound much like crud in the lines, so I started to wonder if 
> maybe this wasn't a coil problem.

Coils have a funny habit of failing slowly, and masking the symptoms. 

This might also be a case of oil on the clutch disk. I think there is an inspection cover on the bellhousing. Remove it and check your clutch for oil. Perhaps a leaky input shaft seal?? 
>     

8) At times, the car would run fine (usually just before I would set 
> aside some time to work on it).  One day, however, I pulled out in 
> traffic and made a sharp righthand turn.  I lost almost 95% of the 
> engine's power and pressed the pedal all the way to the floor.  The 
> engine groaned significantly, and then as though a blockage cleared, the 
> engine cleared itself and everything was fine.  It almost seemed like 
> there was crud in the bowls of the carbs and the sharp turn sloshed 
> whatever it was into the line.

Either that, or a bunch of oil got on the clutch, and after the friction burned it off, you got clutch to flywheel traction again. 
> 
>     9) Today, the car started out fine and I drove about 30 miles to a 
> meeting (on one of the last top-down days in New England).  On the way 
> back, I lost 80% of my power again as I was pulling away from a stop 
> light.  I was able to get up to speed but I had to keep the pedal to the 
> floor just to do 65 on the interstate.  The car was significantly 
> backfiring and would barely be able to move under its own power when 
> accelerating from a stop light.  It would also stall occasionally at 
> stop lights.

Now THIS sounds like the coil/dist/fuel problems again. 

Take your coil to an Autobone, their parts people are supposed to be trained by Wells Ignition on how to properly test primary and secondary windings with an ohmmeter.

Once you've cleared the coil, check for loose point plate and bushing on the point plate. also vac advance. 

Let me know how you make out. You seem to have a few gremlins you need to exorcise <G>

Best Regards
HANK



> 
> So, before I start pulling things apart, does this sound like blocked 
> lines, fouled carbs, a bad coil, all three or something else?
> 
> I am not a mechanical wizard, so everyone's suggestions concerning 
> things to focus on really do help.
> 
> Thanks in advance.
> 
> Steven J. Serenska
> 
> P.S. One other factor that might be coincidental.  This car has always 
> had a throwout bearing issue that causes it to squeal now and again.  In 
> the past, this would occasionally happen when shifting into first at a 
> stop light.  To remedy the problem, I would simply shift back to 
> neutral, reengage, and the problem would go away.  Now, however, this 
> grinding/squealing noise is happening a) more frequently, and b) also 
> when I downshift to second.  I'm not sure this is related to the loss of 
> power/backfiring/groaning problem, but I thought I would mention it anyway.
> 
>  _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are the property
> of the writer, please attribute properly. For help, mailto:vv-help at corvair.org
> This list sponsored by the Corvair Society of America, http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options: http://www.vv.corvair.org/mailman/options/virtualvairs 
>  _______________________________________________
>