My Nova doesn't accelerate as quickly anymore.

[Pfeil]

18 minutes ago, padgett said:

Just a minor quibble, fed law was in 67 for the 68 model year. Same time side markers became mandatory. Often the year of the law and the model year it applied to were different. Coulda swored my 63 split window had a draft tube but they say the memory is the second thing to go and I forget.

 

And then there was the '74 seat belt interlock...

What I'm talking about is when the devises appeared on the model year of the car.

 

FYI. A.I.R. when first appeared in 1966 Ca. cars to 1974 had the purpose of blowing air through tubes at the exhaust ports or sometime the tube extended to point right at the exhaust valve. The reason or theory was it would blow air like a bellows does at the smithy to further complete combustion. Problem was we started seeing a lot of burnt exhaust valves....but it did work.

A.I.R. has a different job with a car with a catalytic converter. It's purpose is to introduce air into the exhaust manifold to help the catalytic converter heat up. When IDIOTS remove the A.I.R. pump on a catalytic converter equipped car the  oxygen is removed so the converter can't burn off the CO and HC's and then the catalytic converter gets clogged up.

 

FYI, 1974 pre cat cars have a  idle and cruise CO of about 1 1/2% to 2% and HC of about 200-300 PPM of HC.

When the 1975 cars came along the CO was brought down to .01%- .05% CO and from as low as 10PPM- 50PPM HC. That's a significant reduction in emissions. That's also why it's ILLEGAL to remove these emission devises.  

[mike6024]

If it were mine I'd be considering an aftermarket distributor. How about this one?

 

https://www.summitracing.com/parts/sum-850050?

 

Electronic, magnetic trigger, mechanical advance ( centrifugal )

 

[Pfeil]

1 hour ago, mike6024 said:

If it were mine I'd be considering an aftermarket distributor. How about this one?

 

https://www.summitracing.com/parts/sum-850050?

 

Electronic, magnetic trigger, mechanical advance ( centrifugal )

 

It's not emission compatible to his car. It doesn't even have a vacuum advance-Poor gas mileage!

[Larry Schramm]

Fix the basics and fix it back to original design.

 

One more aftermarket item can cause more issues with your car. 

 

When I was a car manufacturer service rep calling on dealers and a customer came into the dealership complaining of electrical issues the first thing that I asked was "Does the car have any aftermarket anything?".  And I mean anything like alarms, remote starters, aftermarket radios, other stereo stuff, ANYTHING. Before we would look at electrical issues all that stuff would need to be removed/ disconnected and the damaged wires fixed.  And a funny thing happened when that was done.  The vehicle worked properly and did not have any electrical issues. 

Edited April 26, 2020 by Larry Schramm (see edit history)

[Dave39MD]

I could be losing it but didn't you have another thread on spark plug gap? I can't find it.

 

Dave

[padgett]

This is at least the fourth thread on this car. That said a modern flow-through Catalytic Converter lights off faster than the old pellet type and make a good muffler.

Second *when tuned properly* a Quadrajet will have lower emissions and give better MPG than a 2GC.- later ther was a 2bbl version of the QJ.

There were several cars of the '90s that did not need EGR to meet requirements, was more to reduce NOX by lowering temperatures. As I said a car tuned for EGR will not run properly without it.

An "open loop" engine can be tuned for power, mpg, and low emisions. Hard part for the manufacturers was the required 50k mile "emissions warranty" to achieve essentially 50k no maintenance often the kitchen sink was thrown at the engine. Plastic caps on the idle mixture adjustment was part.

 

About the only change the dealer was allowed to make was the radio, seat covers, undercoating, and adding the camper option (if a hatchback).

 

Today a lot is available from the aftermarket that can make such a car much nicer and meet emissions requirements. Replacing the THM350 with a 700R4 is one.

[Pfeil]

1 hour ago, padgett said:

This is at least the fourth thread on this car. That said a modern flow-through Catalytic Converter lights off faster than the old pellet type and make a good muffler.

Second *when tuned properly* a Quadrajet will have lower emissions and give better MPG than a 2GC.- later ther was a 2bbl version of the QJ.

There were several cars of the '90s that did not need EGR to meet requirements, was more to reduce NOX by lowering temperatures. As I said a car tuned for EGR will not run properly without it.

An "open loop" engine can be tuned for power, mpg, and low emisions. Hard part for the manufacturers was the required 50k mile "emissions warranty" to achieve essentially 50k no maintenance often the kitchen sink was thrown at the engine. Plastic caps on the idle mixture adjustment was part.

 

About the only change the dealer was allowed to make was the radio, seat covers, undercoating, and adding the camper option (if a hatchback).

 

Today a lot is available from the aftermarket that can make such a car much nicer and meet emissions requirements. Replacing the THM350 with a 700R4 is one.

You can add aftermarket parts as long as they are certified and marked emission compliant. 

[padgett]

I'm not in California but is a good idea.

[mike6024]

1 hour ago, padgett said:

I'm not in California but is a good idea.

 

'75 and earlier are exempt from smog checks in California by the way.

 

[mike6024]

Yes that's true, some parts are certified compliant and some are not. And whether you will be getting a smog check is not relevant. Once when I replaced a carburetor I got a certificate with it saying it was California certified. I kept the certificate in the car with the owner's manual.

[mike6024]

The OP is not in California is he?  

[padgett]

But what does Indiana want ?

[Pfeil]

1 hour ago, mike6024 said:

 

'75 and earlier are exempt from smog checks in California by the way.

 

That's true, however cars with exhaust controls ( 1966-1975) must retain their emission systems. If the AQMD or BAR, determine the state is not meeting it's air quality standards, or cannot meet it's self imposed carbon offset, then and without referendum those cars can be brought back into the smog check program.

 

Mike you need to read the laws!

[Pfeil]

1 hour ago, mike6024 said:

The OP is not in California is he?  

Doesn't matter because there is Federal anti tampering laws as well.

[Graham Man]

Was this car stored?  Mice like to put stuff in the muffler... I use a greasy rag to plug the muffled during storage. 

 

What changed since the last time it ran good?

[Larry Schramm]

I think it might be time for the owner to determine his best course of action based on all of the recommendations that have been made and let us know what he found.  I am not sure he has had the time to process and do all of the recommended checks??  Just a thought.

[mike6024]

"I'm not in California but is a good idea."

 

it was Padgett that initially mentioned California, and I wasn't sure why. Was it because the OP had, at some point, mentioned he was in Calif? I didn't think so but wasn't sure. I'm still not sure why it was brought up.

[padgett]

Well not exactly. What I suggested was that a 17056114 was a '75 Calif emissions carb.

[SuperNova75]

The misfiring sound is just my cylinder burnt or something, I don't have $1,000 to fix the 1 or 2 cylinders that are misfiring. Idk what I can do, the car is going to be done probably soon or it will blow up or the engine will be irreparable and I'll need to pay more than $1K. So Its done, thank you everyone for the responses and your time.

[TerryB]

Did your car have this miss before the work you did?  It seems like a diagnosis of burnt valves was rather new info.   I hope you can check into this and not write the car off just yet.