SNAFU

Hi folks,

I have an 85 Mustang with a 5.0L, 5-spd. The motor is stock, and I'm trying to keep this as a daily driver. The carb
was leaking gas on the manifold, so I took that as a sign to replace the unit. I bought a remanufactured Holley carb,
#64-3609, which is basically a factory replacement for the original 4180C (i think I've got my part numbers right!).

I installed the carb, along with all new gaskets sandwiched in the factory spacers. Reconnected the lines and fired
it up after splashing some gas past the butterfly. The car runs, but not well. I checked for an open vacuum line,
but it's hook up right (well, at least as it was before I started!).



The motor is chugging and reluctant to rev. Not that I want to. It sounds as though the distributor is hanging up
or binding under the cap. I plugged the vacuum hose that runs to the air cleaner (white golf tee), and checked vacuum
at the base of the carb. At idle it registers 4 in Hg, and spikes past 10 with short revs. Is that enough vacuum? WTFrick
is going on guys? I didn't touch the distributor, but it acts like I spun it 20* off center. IDK! And I loaned out my
timing light so I cannot check the timing now. Any help from y'all would be GREATLY appreciated!

Also, you can see in the pic that the pipe centered at the top of the front bowl is crimped at the curve. It was bent
like that when I got the carb. Is that a problem? The fittings (front & back) into the bowls are loose too, which could
be an issue. I plan to permatex those in place.

mjr46

the tubes on the bowls are just vents, I wouldn't be concerned about those, and if timing wasn't touched and the car ran fine before, I wouldn't mess with timing cause you'll end up causing another prob, what you need to do is use the vaccum gauge to set the base settings, using the small little screws on the side of the carb, you set the mixture for the idle circuit, first get the idle set to desired rpm then using the vaccum gauge , turn the small set screws all the way in until car starts to stall then back them out until highest vaccum reading can be obtainrd, these set screws are located on the side of the carb on the metering block, but 4 in hg seems awful low like you got a large vaccum leak, the egr spacer plate underthe carb I have often found to be a prob on these cars, = gets warped, spray all around the base of the carb and all the spacers with carb cleaner and listen for a change in idle, or use a can of propane and put a piece of hose on the end and sniff all around that area and shove hose in places it's hard to get to, propane will be sucked in where there is a leak and idle will smooth out ...hope this helps

SNAFU

Thanks for the input!!! My car-guy friends all monkey around with modern FI Mustangs, so I couldn't ask them for help that would be of any help.

I wasn't sure about the vent tubes, and frankly I'm still trying to relearn the terms to acccurately describe the different parts on a carb'd engine.

The car ran fine before, although the gas vapors made things inside the car a bit smelly. So I knew that the dizzy was working fine prior to installing the new carb, which is why I left it untouched.

I will check when I get back home, but IIRC the replacement carb is similar to the 4180C in that the idle screws are blocked and cannot be adjusted.

I wasn't sure if 4 in-Hg was low or not at idle, so I appreciate your feedback. I will pick up a can of carb/choke cleaner today and look for a vacuum leak at the base as you suggested. I wonder if that EGR plate is still available from the parts store? The original plate was loaded up, and I did an OK job cleaning those recessed areas (I spent more time trying to clean the gasket mating surfaces). Maybe I dislodged some carbon and plugged up the vacuum thingy on that plate located to the back of the carb (I told you I don't know the proper terms yet!). I also used the correct gaskets and I'm quite confident that I oriented them the right way too. I'll keep at it!

Thanks again for the help!

mjr46

iirc edelbrock sells them for the performer 302 intake, check fo such on summit

mjr46

they make this but it eliminates the egr iirc
http://www.summitracing.com/parts/EDL-8017/

mjr46

found it!!!!! ignore the above post.........if yours in fact is warped here is a replacement from edelbrock:

http://www.summitracing.com/parts/EDL-8053/?rtype=10