SuperNova75

My Nova doesn't accelerate as quickly anymore.

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My mechanic friend says my car doesn't have a catalytic converter and its pre-emissions so doesn't need an egr valve too apparently. And the red wire is the electric choke.

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Posted (edited)
45 minutes ago, SuperNova75 said:

My mechanic friend says my car doesn't have a catalytic converter and its pre-emissions so doesn't need an egr valve too apparently. And the red wire is the electric choke.

 

I would look at replacing the pole piece then.  On my car and this would happen, I would be accelerating and the car would seem to die.  Replaced the part and all is well.

 

No EGR??  I believe it is supposed to have an EGR.  There is really no downside to having an EGR on the engine under normal driving as long as it is working properly.  I would be sure to have a working EGR. Plus with no EGR, you will increase emissions.

 

Vehicles were/are designed by smart engineers.  Everything that is on and engine is designed to work together.  If you remove one thing it can have an affect on another item and maybe performance.  Engine and vehicle design is like a musical song.  If you remove a bunch of notes in the middle of song it will not sound right. 

 

Edited by Larry Schramm (see edit history)
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12 minutes ago, Larry Schramm said:

 

I would look at replacing the pole piece then.  On my car and this would happen, I would be accelerating and the car would seem to die.  Replaced the part and all is well.

Thank you !!

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2 hours ago, SuperNova75 said:

My mechanic friend says my car doesn't have a catalytic converter and its pre-emissions so doesn't need an egr valve too apparently. And the red wire is the electric choke.

Your car is not Pre-emissions and came with a catalytic converter I mentioned before some of the things that are missing ( emission wise) on your car. Again I said below:

n the first picture I see the ATC air cleaner is inoperative, I also see the TVS switch vacuum hoses missing. On the last picture with the air cleaner is off there is a vacuum hose ( To Auto Trans Vacuum modulator? )  bent over to 90 degrees and appears there might be a vacuum leak there. The intake manifold is suspect, is it the original manifold/where is the EGR valve? I see a vacuum hose to the distributor, Where is the distributor getting it's vacuum signal?. It's supposed to get it from the TVS switch and not straight intake manifold vacuum. The TVS switch gets it's vacuum from the carburetor's ported vacuum and then if the coolant temp.  is at operating temp goes through the TVS sw. to the distributor. 

 

 

I suggest you get a factory service manual and then attempt a fix and only after you re- equip your engine back to factory standards and emission standards for 1975.

If your mechanic friend says your 1975 Nova is pre emissions I suggest you find a mechanic that knows the vehicle and the law pertaining to your vehicle. 

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2 hours ago, Pfeil said:

Your car is not Pre-emissions and came with a catalytic converter I mentioned before some of the things that are missing ( emission wise) on your car. Again I said below:

n the first picture I see the ATC air cleaner is inoperative, I also see the TVS switch vacuum hoses missing. On the last picture with the air cleaner is off there is a vacuum hose ( To Auto Trans Vacuum modulator? )  bent over to 90 degrees and appears there might be a vacuum leak there. The intake manifold is suspect, is it the original manifold/where is the EGR valve? I see a vacuum hose to the distributor, Where is the distributor getting it's vacuum signal?. It's supposed to get it from the TVS switch and not straight intake manifold vacuum. The TVS switch gets it's vacuum from the carburetor's ported vacuum and then if the coolant temp.  is at operating temp goes through the TVS sw. to the distributor. 

 

 

I suggest you get a factory service manual and then attempt a fix and only after you re- equip your engine back to factory standards and emission standards for 1975.

If your mechanic friend says your 1975 Nova is pre emissions I suggest you find a mechanic that knows the vehicle and the law pertaining to your vehicle. 

The engine is from 1974 there is no place for an egr valve, its a non egr manifold and my friend has proven a lot of people wrong. I'm not trying to be disrespectful but he has worked with my car and I for awhile and recently hasn't had time, he says it's pre-emissions and that's what I am also getting from research but I can't argue or agree or disagree with most car crap because I don't know anything because I haven't been taught it. Still, I am grateful for everyone's responses. Thank you.

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+1 on what Pfiel said. Regardless of the current engine, the CAR came with a EGR (GM since 1973) and Catalyst (75 was first year). I had a very similar 2bbl 305 for many years (wound up with dual quads but another story).

 

Bottom line: we have not a clue what you have now. 350 but which heads, which cam, which  carb (GM 2GCs came in many kinds from 178cfm to 435 cfm, 17056114 sounds like a 75 Calif emissions carb body but what that needs is hard to determine). all make a difference. Age is also a factor. Collapsed lifters and thoroughly-ex cam lobes are common and will kill power as will a stretched timing chain.

 

Frankly I have doubts about anyone who says it is not an emissions car.

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Looks like my 67 Camaro except I had no rear muffler and side outlets. Screwed up AADCO rear sway bars for stock cars.

 

 

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Posted (edited)
2 hours ago, SuperNova75 said:

The engine is from 1974 there is no place for an egr valve, its a non egr manifold and my friend has proven a lot of people wrong. I'm not trying to be disrespectful but he has worked with my car and I for awhile and recently hasn't had time, he says it's pre-emissions and that's what I am also getting from research but I can't argue or agree or disagree with most car crap because I don't know anything because I haven't been taught it. Still, I am grateful for everyone's responses. Thank you.

The first cars with exhaust emissions came in 1966! The way the law works is you can install a newer engine in a older car, but it must remain emission compliant to the year of engine, and in the opposite direction it is technically illegal ( Federal Emission laws) to install a old engine into a newer vehicle using the old cars emission systems.

As Padgett says; EGR goes back to the 1973 model year for your car.

Like I said before, get a service manual to see what your car needs and when that's done repair it properly. 

Edited by Pfeil (see edit history)

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Unlike the A.I.R. the SBC EGR was wentirely in the intake manifold (not for Cosworth Vegas) and fed from the exhaust crossover (used for carb heating) to the intake. So all you needed to delete the EGR was a non-egr intake manifold. (also there were block off plates for EGRs).

Thing was the engine was designed for EGR dilution at cruise and MPG would head into the toilet if just removed the EGR without making other changes.

Guess few are left who were there. Could make a pellet remover from a long mag 3/4" lug nut.

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Posted (edited)

I agree that the first year for vehicle emissions was 1968 when PVC Valves(positive crankcase valves) were installed.  These valves sucked the crankcase vapor from crankcase and and put it below the carb to burn the vapors.   

 

Before the PVC valve, cars had a "road draft tube" that allowed the crankcase vapors to vent to the atmosphere.  Here is a road draft tube on a SBC engine. The black tube on the back of the engine.

 

image.jpeg.15f60585b500ef19b2638c4111675abe.jpeg 

Edited by Larry Schramm (see edit history)

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Posted (edited)
6 hours ago, Larry Schramm said:

I agree that the first year for vehicle emissions was 1968 when PVC Valves(positive crankcase valves) were installed.  These valves sucked the crankcase vapor from crankcase and and put it below the carb to burn the vapors.   

 

Before the PVC valve, cars had a "road draft tube" that allowed the crankcase vapors to vent to the atmosphere.  Here is a road draft tube on a SBC engine. The black tube on the back of the engine.

 

image.jpeg.15f60585b500ef19b2638c4111675abe.jpeg 

NO, the first PCV was 1961 in California and 1962 for Federal cars. The first cars with exhaust emission control was 1966 in Ca. and 1967 for Federal cars. The first year for Catalytic converters was 1975 although some foreign cars could pass with Thermal reactors like BMW and Honda but soon standards were too strict and they went to catalyst.

Edited by Pfeil (see edit history)

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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...

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45 minutes ago, Pfeil said:

NO, the first PCV was 1961 in California and 1962 for Federal cars. The first cars with exhaust emission control was 1966 in Ca. and 1967 for Federal cars. The first year for Catalytic converters was 1975 although some foreign cars could pass with Thermal reactors like BMW but soon standards were too strict and they went to catalyst.

 

I will agree with you as I thought '62 was the first PCV year but a quick search showed up '68, that is why I said '68.

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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.  

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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!

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Posted (edited)

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 by Larry Schramm (see edit history)
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I could be losing it but didn't you have another thread on spark plug gap? I can't find it.

 

Dave

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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.

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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. 

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

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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.

 

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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.

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