Novusuhu

Hey everyone

I will take the original qjet of my 77 L48 off tomorrow. Because it’s the first time I remove a carburetor, I want to ask some questions before I begin (see pics below):

1. Are these the bolts that hold to carb in place on the intake (red circles in the picture)?

2. What is this and do I need it? (light blue circle)

3. Do I have an electric or a ‘heat-stove’ choke? I read that an electric choke is superior to a ‘heat-stove’ choke …
If I don’t have an electric, what are the parts that I need for an electric one?

4. What is this and do I need it? (green circles)

5. I thought there were always two fuel lines that go to a carbu… I only see one…?

6. What is a good product to clean a carbu, so the top gasket won’t ‘dry out’ or be damaged? Can I spray it all over the carbu, or do I have to seal off some places?

7. Is this a vacuum line? It is attached to the power brake equipment next to the engine (LH).

8. Do I need the Idle stop solenoid that is attached to the carbu? The wire goes to the AC…


Upgrades already done:
- long tube headers.
- true dual exhaust 2.5”
- A.I.R. system delete
- repaired finned alum. valve covers (still not in place).
- cleaned and painted everything on the engine besides the AC, intake and carb.

Upgrades for August (will be in the USA for 3 weeks, travel next week from Belgium):
- Performer 2101 intake (+ EGR delete)
- tuning Qjet
- install the repaired valve covers
- make and install new spark plug wires



Pictures:

1. Are these the bolts that hold to carb in place on the intake (red circles in the picture)?





2. What is this and do I need it? (light blue circle)





4. What is this and do I need it? (green circles)

CA-Legal-Vette

1. Yes

2. No idea

3. Electric choke

4. Guessing this is a vacuum switch for the air cleaner damper

5. Only 1 fuel line for q-jet

6. Not sure what you mean

7. Yes

8. Although it’s the same solenoid as used for idle stop, it raises the idle on some cars when the A/C is on.

Bikespace

Are you sending this out to be rebuilt, or rebuilding it yourself?

1. ???
2. That's your heat stove. There's a loop that goes into the intake. One of the ends of the loop connects to the choke.
3. Email Lars on this forum to get the correct electric choke for an 80 (perhaps you can find it at RockAuto or similar). You'll need to add the circuit, too.
4. Vacuum switch. One doesn't look like it goes anywhere, so right now it's just a low-temperature vacuum leak. Try to find a vacuum diagram for your car, and it's specific options (AC, transmission, etc).
5. Some early C3s came with Holley carbs stock. Those have two fuel lines (or one line with a wye, feeding both bowls of the carb).
6. Are you committing to taking it apart anyway? If not, why are you removing it from the car? Email Lars for his carburetor rebuild papers, and/or read Cliff Ruggles' book.
7. I don't see a photo, but there should be a large vacuum line that goes to the power brakes, along with a right-angle check valve in the brake booster.
8. ???

bmotojoe

#1. Yes, but before you remove the bolts remove the small sheet metal screw securing your brake booster metal pipe to the throttle cable bracket. Doing so gives you better access to the booster pipe and fitting going into the carb when you disconnect that. If the fittings don't split apart easily, spray a little WD-40 or penetrating spray on the coupling or your pipe will twist and kink. When reinstalling carb make sure you tighten the bolts in a cross pattern. I tighten mine to 144 in. pounds or 12 ft. pounds. If you over tighten the front long bolts you can actually bend (warp) the air horn. The fuel filter nut I tighten to 18 ft. pounds.
#2 Yes for your hot air choke, if you go electric they make a block off plate and there is a fiber gasket under it.
#3. Hot Air Choke
#4. That is the TVS EFE temp sensor that opens the vacuum operated EFE actuator on the passenger side exhaust. I don't see a vacuum line connected to the bottom port of that switch.
#5. Just one to carb.
#6. I wouldn't just spray a carb to make it pretty. That carb looks like a nice original that just needs a kit. I did my 77 A/T A/C with cruise using a kit I purchased from Cliff Ruggels and it wasn't that bad. It was the first time I opened up a Qjet.
#7. No photo?
#8. If A/C is working it does bump up the idle speed so at a stop because of the compressor load on the engine it will not bog the motor down.

Novusuhu

Yellow circle

bmotojoe

That is your brake booster pipe W/support I talked about in #1 response. If your car is an early 77 build it was yellow cadmium plated in color, if its a later build car it was just the silver zinc plated color. Either way, be real careful when you go to remove it.

Novusuhu

What is second part (second green circle)?

CA-Legal-Vette

Oops. Joe is correct. My mistake.

pd64

This is for 78 but will be the same:

bmotojoe

If compared to a 77 the drawing above will work for a L-82 or a L-48 High Altitude or California emission car. Yours looks to be standard L-48 emission car. Also, if you are going to keep the hot air choke I would replace the 1/4" id silicone hose circled, looks like a crack is forming and this could cause a vacuum leek. The OEM hose is real thick vs. just a replacement hose.

Novusuhu

I will replace the hot air with an electric choke.
What is the email of Lars?

lars

Why? The hot air chokes work great. You gain nothing going to electric.

Yes

Your hot air choke system. Yes you need it. The hot air choke system works very well.

You have a hot air choke, which works just fine. No, electric chokes are not superior. Use an electric choke if you have a manifold that does not have the hot air choke provisions.There is no reason to disable what you have.

Thermal vacuum switches to turn vacuum signal on/off to the distributor vacuum advance and EGR systems. By delaying vacuum advance when the engine is cold, the engine warms up quicker. You have a nice, original engine compartment - people pay a lot of money for an original setup like that. Why do you want to alter it and hack it up?

No, there is only one fuel line to the carb.

Spraying carb cleaner on the outside of the carb will gain you nothing. If you just want to clean things up, put a plastic bag over the top of the carb, spray it with "gunk" engine degreaser, and then blast it off at the car wash. It will make it clean, but it won't do anything for the performance or operation of the carb itself.

Yes. It's your power brakes.

Again, why do you want to remove and disable things? The solenoid was put there for a reason - to make the car more driveable. If it works, leave it alone. If it doesn't work, replace it or fix it.

Lars

Novusuhu

Thank you for the advice Lars!
I will keep the original choke system then. The solenoid stayed anyway, I just wasn't sure if it was a solenoid.

The only thing that will be deleted is the Egr system because I don't need the emission equipment in Belgium, and the Performer intake that I got doesn't have EGR provisions.

Novusuhu

Ok, I decoupled the power brake booster vacuum tube, but the metal vacuum tube broke... I was VERY careful, but suddenly the tube twisted (kink) and broke...
Do I have to make a tube myself? I can't find a metal tubing part for a 77..., only for the years 70-73 and for 78-...

bmotojoe

Sorry to see that, I know you live overseas so this may be an option, not correct but it will work. The tube is nothing special so yes save the fittings use 3/8" steel tubing bend the tightest 90* you can and flair it, Not sure but I think its called a double flair.
Keep your eyes open here and e-bay for the correct one. 75-77 used the same pipe just different plating.

bmotojoe

This is a Dorman product sold at Home Depot product number 624-027. It has the basic shape of the inlet to carb but the length would have to be cut shorter. I went to Dorman's site and the pipe is about 28 inches long. Might be worth a check in person if fittings are the same but for $5.00 cut, bend to fit your needs what the heck. There will be no bracket welded to it but it seems you have found a good welder from another post of yours.
Link:https://www.homedepot.com/p/OE-Solut...-027/308752837
Or E-Bay Link:https://www.ebay.com/sch/i.html?_fro...4-027&_sacat=0

mk's78

OMG what a dream come true..Just wanna say that when you replace the Qjet I would certainly be interested in purchasing both steel air tubes that are used for the Hot Air Choke system..I need them badly for my 78 Qjet!!!!

mk's78

Mike

lars

There's no Home Depot in Belgium.

keithl1967

Mike:

I did a take off on my '77 two years ago--went with a edelbrock performer and holley carb w/ electric choke. I still have all of the take off parts, including the carb, manifold, and hot air choke parts...

PM me if you're interested...

Novusuhu

Do you know what type of fuel filter a 77 qjet needs?