Instead of opening a hundred threads asking a hundred different questions I figured I contain it to one thread. Naturally I will be posting pictures as I go.

A quick background about me: I'm 25 and work in the IT field, 4 years as a system administrator for the Marine Corps (0656) and now as a help desk analyst while the GI Bill pays me and school. The most I've ever done to a car are oil changes and I seafoamed my 94 Z28 once.

Scheduled for this weekend is going to be a tune up for the motor. It starts right and has a pretty good idle, but under acceleration sounds like she maybe missing, there is a lot of heat passed in the cabin during drives lasting longer the 30mins, and there is a hissing from the right hand side of the engine bay after shutting her down but I don't see a steam jet or anything. As for the heat it starts at the peddles and slowly starts to fill up the cabin. Car as smells like its running very rich, smells like a boat.

I'm hoping all this can be fixed by changing all the fluids, spark plugs, and wires.

Now I have no experience doing any of this, I have a Haynes repair manual as guidance. Am I getting in over my head? My main goal is to basically do as full a maintenance as I can with out really tearing anything apart.

Sorry for the book, but thanks in advance for any advice.

 

You will need to buy some basic tools to start. A timing light is a must and if the 75 still has points-type ignition you will need a dwell gauge. I would plan on replacing the distributor cap and rotor as well as the wires. Make sure you label the plug wires and write the same number on the old cap before removing them so that you get the wires installed in the right order.

There may still be some papers available on the forum by Lars that cover tuning. If you follow them you should end up with a good-running engine. If you can't find the papers maybe you could PM Lars and ask him for copies.

A properly tuned engine may run cooler and help the cabin heat problems, but cabin heat is a common complaint in the C3 world.

There is probably a wealth of information on the web for tuning a 350 engine. The Vette engine is no different from other 350's when it comes to tuning.



Rick B.

 

Awesome thank you, sorry but what do you mean by points type ignition and how would I be able to tell?

thanks

 

HEI electronic ignition was standard in 1975. Distributors with points and condenser were from earlier years so you don't have to worry about it.

 

A typical tune up on a 75 is distributor cap and rotor, plugs and wires, PCV valve, air filter and fuel filter. That will give you a good base to start from.
You also want to check the igntion timing with a timing light. Most driveability issues with the 75 style come from the carburetor. The chances of it being messed with in the past 35 years is VERY high. The Quadrajet is finicky and has a lot of adjustment points. When they are set up right, they are awesome. When they aren't, they bog, pop, cough and chug.
As far as the heat, its typical for the catalytic converter to fail and overheat. Both of my 75's had failed cats that got extremely hot. You can remove the cat and swap in a test pipe to check it or replace it with a new cat.
For a new guy, I think the most important thing is to do one step at a time. Never tear the car apart to the point where it is undriveable for more than a few days at a time or torn down to the point where you have a major undertaking to drive it again.
This is where people get overwhelmed and either ditch the project or get way too deep into it and get in over their head spending time and money they could have put towards a better car.
You want to keep it as a driveable project.

 

You have a good book to start with, there are others that will also serve you well. I suggest you consider buying one of the AIM manuals in electronic form. I know that Willcox sells them and I have used the dickens out of my 71 and my 77 AIM manuals. You can sort by name and find the reference drawings that help you when working on the car.
And never hesitate to ask questions on the forum. The people here are highly informative, technically competent, and some of them even know what they are talking about. Just kidding. I was where you are now in 2006 and the folks on this forum helped me a great deal.
Which city in NJ are you living in? Lots of good guys with Corvettes in NJ. I'm in PA but willing to help you if I can. I own two 77's and have one 71 in restoration now. Have learned a lot, have more to learn, but keep the questions coming.
Best of success and thanks for your service.
David

 

You guys are awesome, i wasnt expecting to hear anything till tomorrow. Also I'm going to snap some pics of the engine to0 so you guys can have some references.

 

You're a smart young fella and you sound like you are willing to learn. If you have a good streak of 'curiosity' and are stubborn, to boot, you have all the qualities necessary to be a C3 'addict'.

Buy two documents: the Assembly Instruction Manual (A.I.M.) for 1975 and the Chevrolet Chassis Service Manual for 1975. The AIM can be purchased either as a paper document or as a CD with search capabilities...I have both and use both. Once you get those documents, you will understand what each is to be used for and why they are so valuable to DIY Corvette owners.

A good tune-up is not a difficult task on a 1970's vehicle and that is the case with the Corvette, also. Except for changing spark plug wires. But, consider it a 'rite of passage' into the ranks of C3 ownership. If you haven't changed plug wires...and re-installed all of the engine hardware when you got done...you really aren't a "full-fledged" Vette-head. The CCService Manual will give you all the info you need to accomplish that task. It will also give you all the info you need to properly adjust and set-up the Q-Jet carb {which I'm sure could benefit from that bit of work}. Good luck! And, keep asking questions on the Corvette Forum.

 

Before you pull the plug wires, snap a lot of photos of how it was together. Get some masking tape and mark the wires as you take them off, the more reference material the better.

 

So a complete lack of coolant could be causing some of my issues.

Here are some shots of the engine:

 

In your third pic there is something missing; port at base of carb. Idle mixture screw? I am not familiar with 1975s but here is a 1974 carb.

 

Not a carb expert, but I am pretty sure that screwdriver shouldn't be sticking out of the baseplate.
I notice it has a cannister fuel filter, which is not a bad idea, but keep in mind that there is a filter IN the carb, in that big hex head thing that says "FILTER". If that gets clogged, the car will run lean and hot.

 

Welcome to the club! I'm kinda where you are, but a little further in. Doing a complete restore on my '71 at the moment and have an '84 that likes to eat rocker studs.....

Good luck.

 

Okay, first of all great shots of the engine area, you are doing the right thing here to start by documenting where you are starting. Good advice from those down this path previously is to take lots of pictures and buy yourself zip lock style bags in various sizes. If you remove something from the engine label it, photograph it, and bag it. I know it is a lot of work to do this but having lost parts and gotten confused in the past I can tell you this will save you lots of time later, honest.

Also, and this may sound odd, but you can use your finger as a pointer when you have a question about a part on the car. Point, take that picture, post it and ask your question.

I see a fair number of wires that have either been cut or pulled out of place on the passenger side of the engine bay. Missing A/C belt tells me your A/C is not working or may not have been for the previous owner. All things to write down and document. Have never seen an in-line filter and the carb filter used at the same time, interesting.

I would think it valuable to have the up close and personal inspection of the car by another Corvette owner with knowledge of the 75. This will help you to document what they see. Safety first. Engine important but brakes and steering for control are top of the list in my book. Both should be looked at in addition to the engine.

How much information did you receive from the seller about the car?
Any documentation to tell you what it was originally?
If you have the VIN we can learn from that as well as the stainless plate on the drivers side of the car. The more you learn about what it was new the more you can begin to see what you want to do with it next.

You are in for the adventure of a life time and I forgot to mention earlier, welcome to the C-3 newbie club, we were all there at one time.
David

 

I just finished restoring my wifes 75 and cabin heat was the major issue.
I bought FAT MAT off of ebay the 80mil stuff, the guy who sells it had it to me the next day. It will stick real good if you make sure everything is clean. I covered the whole interior tops back space everything. The car is real cool inside now without air. No more hot feet.
The fat mat is the cheapest and best stuff you can use. Ive used dynomat, cost to much.
Im no expert on the vettes as I restore antique cars, 48 on back. But if you need any help let me know and I will tell you what I went through.
Welcome to the forum, great place for info and lots of people that are willing to help.

 

Ok just did the oil change. Found an spark plug wire, labeled 7, just dangling down by the oil filter, and pulled the dipstick out and now i cant find where to put it back in, haha. Help

 

Did the tube come out with the dip stick? The hole for the dip stick is in the left side of the block, between the 3rd and 4th spark plug, though closer to the 4th plug. It is right next to a head bolt.

Where abouts in Jersey are you? We have quite a few Corvette Clubs (always helpful), Corvette Shows, Corvette repair shops and parts shops and there are a large number of Forum members in the area too.

 

I live in Sicklerville just off exit 38 on the AC Expressway, and yeah I think the tube did come off with it.

 

Welcome to the forum. That #7 wire could cause a little rough running. Good luck with the project and keep us posted.

 

Here's a picture of the dip stick tube hole location. This is a junk 67 283 I have laying around, but the hole location is the same.



That's the tube hole, just above the ball stud for the clutch "Z" bar.