70LQ4

The only other place that spring could be from is the Accelerator pump , part of no.33 not 34. Maybe some "engineer" tossed it in there for some unknown reason?

22229stingray81

Right, that's the closest looking one. Maybe somebody put it on top of the accelerator pump rod? I don't know, but as soon as I pulled the air horn off, it fell out of somewhere. Glad I got confirmation that I wasn't missing anything. I'll be extra careful when I do the real thing. Thanks again!

70LQ4

There should be a retainer that fits in the grove on the Pump , they may have left it out. There will be a new one on the pump in the Kit.

22229stingray81

The new TPS finally arrived in the mail today, so I got to work on the 'vette. After looking at the throttle connections on the driver's side, I decided to just leave the carb on the car and take the airhorn off. Very simple, straightforward, and I ran into no hiccups at all! TPS replaced, accelerator pump replaced, and a new gasket installed.

Started it up and let it idle for around 5 minutes after, and no CEL, no leaks; everything seems so far, so good. I obviously need to adjust the TPS and go for a long drive to see if the idle/gas mileage has improved, but I got my fingers crossed.

BTW, I figured out what that mystery spring from the other carb was for. It was the TPS spring. The one on the carb was very small. I'm guessing somebody went in to replace it, lost it, and just used a spring from a pen. And the spring was rattling around the carb the entire time.



One last question though. The shield, or guard, or whatever you call it on top of the carb on my 'vette is missing (see attached pic). Is this part even necessary? I think it's a fuel splash guard or something. Should I just pull it off the donor carb or does it even matter? Thanks!

PcolaPaul

I have a E4ME Q-jet off of a Monte Carlo SS that was in excellent condition when I pulled it off the car last month. It will need a new fuel filter and the filter nut o-ring/seal. It ran perfect and its clean. This carb is supposed to be performance tuned from the factory for the SS.

If you are willing to pay a few bucks for packaging and shipping cost from me to you.. It's FREE!!! I think it will ship anywhere for 20 bucks or less.

I will never use it and one of you smogger guys could get some use out of it.
First PM gets it.
I also have a computer controlled HEI in excellent condition for shipping cost. its nice to live in Florida with no smog inspections!

22229stingray81

Just set the TPS to .56 volts. I thought it'd be more difficult. Love it when that happens

So now it's time for some testing. Nice weather is right around the corner. I'll report back! Thanks again for all the help.

-Nate

22229stingray81

Okay, so I've driven it a couple of times since I replaced the TPS and set it. It doesn't seem to have cured the slightly rough idle problem. It does seem a bit better, but that could just be wishful thinking. I haven't done a fuel consumption test yet either.

So I decided to dive in further. I wanted to check all the tiny vacuum lines coming off the carb. Now, here's where it gets weird. There is a small vacuum line coming off the base of the carb at the rear. It then goes into a Tee, with one end going to some sort of very small tube or wire, and the other going into a REAR vacuum break (choke pull off).

Everything I've read, and pictures I've seen show no rear vacuum break on the L-81 Corvette engine. Is there only supposed to be a front vacuum break? I wonder if this isn't the stock carb...

BTW, I tested the front and back choke pull offs. The front one is fine, but the rear one cannot hold vacuum. I attached pictures of it. Is this a stock part? Why would somebody add it? Since it can't hold vacuum, is it effectively causing a vacuum leak? Thanks!

22229stingray81

Sorry, I don't have a better picture handy, but here's a pic of the rear choke pull off in question. Is this stock?

22229stingray81

Well it's all FINALLY starting to make sense. It should be 17081228 for a non-CA automatic Corvette. Apparently 17081222 is off of 5.0L automatic Malibu, Impala, Caprice, El Camino/Caballaro, Camaro, Century, LeMans. UGH. I wonder what the differences are? And I wonder how much horsepower I've lost. Probably not much.

Well, now we know I don't need the rear choke pull off. I have removed it, and the tee connector, and now I have that single cable/wire going straight into the back of the carb. Could someone tell me if this is remotely correct? And what the hell does that little cable go to? It terminates under a little metal box to the right of the wiper motor behind a relay. Also, I cannot remove the linkage without taking the choke housing completely off... so it's just hanging there for the time being.

Before removal:



After:



Where the little cable terminates:

22229stingray81

Okay, someone clued me into that little wire/tube goes to some sort of air sensor, like a MAP. The correct way is the second picture, with the "tee" removed. I also check the vacuum lines going into the intake manifold below it, and the rubber that was connected to the stainless steel line (I think it goes to the transmission) was perished. So 2 more vacuum leaks fixed in one day. Not bad if I do say so myself