I took my "new" '74 Dodge Dart for a spin today, and it has almost no power at all under WOT. There seems to be a "sweet spot" around 1/3 throttle where it has the most acceleration. I'm thinking vacuum leak, but most of the lines look fairly new, other than one of the vapor canister lines. I'm planning on going over the whole car with a roll of fresh vacuum line, but I'm wondering if this could be a problem with the carburetor? Would my best bet be to rebuild, rebush, and rejet the 1945, or swap it out with a 1920 or Carter BBS? What issues would I be looking at for a carb swap?

Thanks to all,

- Dan

lack of fuel

1. fuel filter
2. fuel pump
3. fuel strainer (in tank)
4. carb

I'd change the fuel filter first........

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

What about all other maintance items? Cap/rotor/wires/plugs/air filter/oil/oil filter? I mean, outside of plugs, none are probably contributing to the problem, but if you don't know when they were last done, they can only confound the problem.

Tuneup would help things, then checking the integrity of the fuel system...of course if the 1974 Holley 1945 has a stock setting of a #58 jet...you will have lack of power in the mains due to lean out...you will suddenly notice after the rejetting that you get back a fair bit of power.
You may also need to review posts on here about timing, and check/plot your curve with a dial back timing light, and after tuneup and carb adjustment, may wish to adjust that too...

-D.Idiot

Yes, lack of power is often blamed on the carb when it is really a distributor issue.
Example, if the mechanical advance is not working, the engine seems to run OK off the initial and vacuum advance timing but goes flat when you go to WOT and the vacuum advance comes-out.
Plot your advance curve, set it for your combination and driving conditions.

Also, do you know what rear end gear ratio is in the car?
DD

Thanks for all the tips. I changed out all the filters, it helped a little. I used the old "spray the carb cleaner around the engine compartment until the engine runs rough" trick, and it didn't take long to find that I have a huge leak at the butterfly bushings. I called around, the only carb shop in the phone book said they wanted $38 to re-bush it, which seems high.

I also noticed that my engine mounts are completely shot; the cylindrical rubber mounts especially. Is it possible to change these myself with my very limited tools, or would I need an engine hoist?

Thanks again for all the help. This forum is great!

$38 is absolutely and fully reasonable for what needs to be a high-precision job. I was paying $35 a decade ago in Denver. Pay it and don't kvetch!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Good to know - I was going to pay it, but it's good to know that's a fair price.

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- Dan in Simi
'74 Dodge Dart Custom

Sounds more than fair to me. Shop labor rates are pushing $80/hour in some places. I would gladly pay double the $38.00 for a quality job.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

One thing that I didn't think about until now, is he might still be running an intact OSAC valve (I think 1974 is an aircleaner mounted variety)...

In this case, get a 3' length of distributor advance hose, and connect one end to the distributor can and the other to the carb port right next to the PCV port at the base of the carb (the 3/8" hose connected to the valve cover)....that "delay" in timing might be killing his initial "acceleration" too....

-D.Idiot

I have my vacuum advance hose plugged into the vacuum tree on the intake manifold, the same place the vacuum line for my power brakes hooks in. Is this a bad spot? Should i have it in the position noted above?(not to thread jack or anything) Thanks!

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Drive it like its stolen, and be glad im not YOUR son...

Definitely the wrong place for it.
You should have it connected to the vacuum advance nipple on the carburetor. There are a fair number of hose nipples on a '74 carb, so make sure you get the right one. You'll want to buy the books described in this thread.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

OK, I bypassed the OASC and ran the vacuum line directly from the carb to the distributor. Aside from a single backfire when first I started it, it runs well, perhaps somewhat stronger. This engine has the California stuff for the EGR valve, I think it's some sort of delay valve, should I bypass that as well?

Thanks for the links to those books, they look like a very good resource.

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- Dan in Simi
'74 Dodge Dart Custom

I've got the carb parts soaking overnight in a can of dip, the base is at the carb shop, and I have a few questions.

First, there was a line at the top of the carb that had only a short length of hose with a screw in the end of it - was it supposed to be hooked to something? When I unscrewed the fitting, there was a little plunger setup that looked like a one-way valve. Link to a picture - you can see the hose in question on the left.

http://i95.photobucket.com/albums/l130/ ... Medium.jpg

Secondly, I took the old jet out, and stamped on it is "61" and then an upside-down "2". Does that mean that it already had a 61 jet in it? Picture:

http://i95.photobucket.com/albums/l130/ ... Medium.jpg

Thanks.

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- Dan in Simi
'74 Dodge Dart Custom

That's a late model 1945 as the "screwed hose" is an idle enrichment "upgrade" to the circa 1977-1978 carbs... and is supposed to help keep a cold engine running and is switched to vaccuum when the engine is cold...have to find a vacc. diagram for a 1978 Volare to see how it's hooked into the main scheme of things, I think most guys just put a plug over the nipple (screw in the hose remnant) and call it good...

If you have a #612 in there and it is a real #61 jet (not a drilled out remanf jet), then it should be OK. (That's stock for all 1975+ Holley 1945's)

-D.Idiot