I had my '79 into a shop a couple of months ago. Paid a boatload of money to have them tune-up the engine including rebuilding the carb.

It was running great when I brought it home. A day or two later, I noticed the performance slipping. It was running real rough at idle when I first started up in the morning.

The most annoying problem is that when I would leave my house in the morning, and make the turn out of my neighborhood... the engine would completely bog down when I accelerated. I noticed that the harder I accelerated, the worse it was. So I learned that if I accelerate slowly, there would be no problem. This problem mostly goes away after it is warm.

The thing that bugged me was that this never was a problem before I brought it to the shop for the tune-up. So I took it back to them, telling them my complaints.

I was told that the bogging down is expected when cold because the rear 2 carb chambers are blocked off until the engine warms up and the choke opens.

First question... is the shop right?

I asked why this didn't happen before and he couldn't give me an answer.

Second question... is it possible this wasn't a problem before because the choke was stuck open?

I picked it back up from them today and it is still doing the same thing!

Any help you can offer will be great!

Thanks!

 

It sounds like the choke is adjusted too rich. It is not uncommon for the choke adjustment to be off whenever the carburetor is removed from the car. There is a secondary lock out on Q-jet carbs. This keeps the secondaries closed till the motor is warm enough.

I believe this is an electric choke. Make sure the power is hooked up to it.

When the engine is cold the choke should snap closed when the throttle is moved. If it doesn't the choke isn't adjusted correctly. After the engine starts the choke should pop open 1/8" to 1/4" from the top of the air horn. If it doesn't the choke isn't adjusted correctly. The next time you have the motor hot (say after you drive it home from work) turn it off and then take a look at the choke blade. It should be completely vertical. If not it is not adjusted correctly.

BigBlockk

Later.....

 

How can I adjust it to be less rich? How would I know if I am adjusting it correctly and not going to far?

If it is electric, what type of connection would I be looking for? A certain shape, color, etc?


Thanks a lot!!

 

An electric choke will have a wire connector plugged into a large (about 2" in diameter) black plastic cover on the passenger side of the carb. Make sure you have power at this connection.

The choke has "rich" and "lean" written on it with arrows indicating direction to move the adjustment. Go easy. These things can be sensitive.

You really need to get a good book on this carb to at least learn what the parts are called. Check the vendors.

BigBlockk

Later.....

 

Although I am a big fan of DIY, you payed good money for those people to square you away. Take it back to them, tell them the problems you are having, and let them make it right. If they are a shop that I would want to return to, they will not give you any grief about it, as it is most likely a simple fix. Ask if you can watch, or at least have them tell you what they are doing to fix the problem.

 

I disagree. They screwed your car up and then tried to blow you off. Do it your self or find another shop.

BigBlockk

Later.....

 

I DID take it back to them, and they insist that is the way it is suppose to be. I can't force them to fix it if they insist they are right, can I? I'd have to prove they are wrong and tell them what they have to do to correct it.

Which is why I need as many opinions on this as possible.

Thanks!

 

Perhaps remind them that you are the CUSTOMER and you are not satisfied with their work. The car is obviously not right because you had to come back. You have better things to do then waste time driving back to them and debate about something that "is right".

If they don't come to the party make sure you tell EVERYONE you know how shonky they are. Also don't forget the Better Business Bureau.

I am so sick of people ripping of vette owners with overpriced tune-ups. We have Chevy SB engines in a fibreglass car. There are thousands of trucks with almost identical engines. I could just image how much they would screw up an engine if you took them a Ferrari or a Lambogini.

Good Luck and don't let them bully you.

Pete

 

Just thought I'd give you an update...

I sent an email to the owner of the shop, which is County Corvette in West Chester, PA, by the way. I explained the situation and that I expect they should get it back to proper running condition.

The next morning, I got a call from the mechanic there that worked on my Vette. He seemed surprised that I was still having trouble, even though it had left there in the same condition I am complaining about. He suggested that maybe the Accelerator Pump has gone bad, which he said was replaced when he rebuilt the carb.

At any rate, I'm taking it back to them this Wednesday. I'm hoping and expecting that I will not have this problem any more when I get it back!

 

Sounds like they are already getting a new bill ready for you. If they rebuilt the carb, then a new accelerator pump is PART of the rebuild you paid for. It also sounds like they don't know their butt from a hole in the ground as far as working on carbs. Find a different shop and don't go back there again.

Dep

 

I don't plan to give them any more money. They already took a lot from me as it is. I guess I better make that clear to them when I drop it off, that I don't expect to have to pay anything further.

 

Now you're talkin'!!!!

Dep

 

Update:

I dropped it back off at County Corvette yesterday. Of course, I couldn't show them the problem, since it has to be cold to do it. But they said that they'll try some other things, like the accelerator pump, to see if they can get it right.

It has also been running really crappy, but of course, seemed to be running ok while I was there!

As I left, the president of the shop took it out for a drive.

I really hope they can get this right!

I'll keep you posted...

 

I had a real hard time coming to terms with this when I first bought the vette. I'd call a shop, and naturally before quoting any labor they'd ask "what kind of car is it" and I'd usually try to lie and say it was a '68 Nova or a custom Chevy.

Eventually I realized that the corvette is set up differently than any other car of its era, not to mention it has less space to work in than just about any car out there. If I think about how many times I've bumped my head on the T-top header or burned my hand on the headers, I understand why mechanics are reluctant to work on vettes without charging a premium.

If you're a cost-conscious consumer, the only real option is to pick up a copy of Vizard's "Rebuild a chevy 350" and Yunick's "Power Secrets", buy some tools, and learn how to do it yourself. It's the only way you'll feel completely satisfied with the effort you put in to improving the condition of your ride.

IMHO, of course.

the blonde weasel

 

I've had the same problem, but my accelerator pump was working fine. My local backyard mechanic thinks it is electrical. He suggested replacing the coil which tested marginal. I put in an Accel coil, distributor cap and rotor. It hasn't eliminated the problem completely, but it has improved it noticeably. I am going to try new plug wires and some more new plugs next.

Couldn't hurt to have them check the electric while it's there!

 

I am so sick of people ripping of vette owners with overpriced tune-ups. We have Chevy SB engines in a fibreglass car.


Good point.

 

i noticed my 75 does that too. it has the stock 350 and an edelbrock 750 on it. if the engine isn't warmed up to about 150* it bogs down when i hit the gas hard. but once it warms up it runs fine.

 

I hate having to come to this forum and explain what the customers fail to do. After reading the thread I feel it must first be explained that the the car that was brought to us not running. In fact it was dumping fuel into the engine to the point where it was a fire hazard.

The "tune - up" was significantly more invloved than the typical plugs and wires and a few adjustments. Also I would like to point out that this a a high mileage car that even the best of the best mechanics would be challenged to get to run like it should.
The tune- up the customer describes consisted of:
Rebuilding the carburetor
Plugs, wires cap and rotor
Complete diagnosis of vacuum system and replacement of all suspect vacuum hoses in entire engine compartment.
Adjust timing and carburetor settings
Road test
Provide indoor/insured/ protected storage until customer got around to pick car up

It bothers me greatly to hear people on this thread get the impression that my company did not stand behind the repairs. We take pride in what we do and ALWAYS go out of our way to take care of the customer even when it may or may not be our fault, and we did take care of the cusomter in this case.

This thread leaves an unfair, negative impression of our customer service.

This car is a high mileage, highly worn automobile. I assure the Corvette Forum community that the customer was treated honestly and fairly as well as with a very reasonable cost. As the customer said, it ran great when he picked it up.
The fact is the car probebly never ran correctly while he had it as it was dumping so much fuel into the engine. The customer called and said it was hesitating after we repaired it. We told him to immediately bring the car back to us. We test drove the car and it seemed fine.
He picked the car up and then contacted me, the president of the company. I discussed the problem and we brought the car back in. Despite not finding any hesitation. I instructed my technicians to remove the carburetor and go through it again. We did so. I have personally driven this car and it operates as good as any 79 ready to go through an NCRS operations check and Perfromance Verifiication.
We have again stood behind our repair and have not charged the customer a dime. The car is now in indoor storage for another week until the customer can get around to pick it up.
If anyonne can instruct me how to give better customer service, please call me at 610-696-7888 and I will implement the change imediately. Ask for Jim Jordan
Thank you

 

It looks like you're still running the Qjet - they can be very cold natured unless setup properly (aka Lars). I had the same prob until I switched to a Holley and Demon - don't have a prob with either one at any temp or RPM.

 

Jim,

I would agree that is more then a "tune up"

It is good to hear from Vette Shops who stand behind their work. As someone who has been "burnt" by some very ordinary "mechanics" it is refreshing to hear a man stand behind his work as you have.

My comments were not aimed at your business but to those people seem to think that someone who owns a Vette can afford to pay for the same repairs 2-3 times. It can be very frustrating as an owner, which I am sure you have experienced yourself, to have to keep going back and getting something fixed which you thought was already corrected.

It is also nice to hear of a business that keeps cars indoor and locked up. There is a local business here that uses an open parking lot outside the workshop. A friend has had his car vandalised whilst at the shop.

Good luck with your business.

Pete