73 Cadillac deville, runs good at low rpm but when you step on it, it runs rough and has no power. I have done a tune up with plugs, points and replaced fuel pump. What next?

15

Asked by May 20, 2012 at 09:49 AM about the 1973 Cadillac DeVille

Question type: Maintenance & Repair

9 Answers

13,835

Check the catalytic converter. If it's plugged you will have similar symptoms.

1 people found this helpful.
2,125

Your fuel line from the tank to the fuel pump may have a small hole in it. Then your fuel pump would be pulling some air into the fuel line, giving poor performance under load.

1 people found this helpful.
15

I checked fuel line for small holes, it is OK. How do you check to see if catalytic convertor is plugged? Do you have to take it off to check it?

1 people found this helpful.
13,835

Usually when cat is plugged the exhaust has a hissing noise instead of a rumble.

2,125

I would try to run a temporary rubber fuel line to the fuel pump, and see how it runs. I suppose you have a new fuel filter. If it is carburetor-ed, the carburetors' jets could be plugged. If the cat is possibly plugged you would have to remove it, to see.

15

There is no cat on this car. Thanks for the ideas tonythe woodsman and aztec626bf. What next? I'm guessing it must be in the carb, which is a quadrejet. I am reluctant to tear into it as they are a complicated carb.

13,835

If you go to the Carburetor Exchange you can get a kit and they supply a very helpful schematic with the kits.

15

i have the carb kit ordered, will try that next.

15

i finally found the problem! It had a double walled exhaust pipe from the y-pipe to the muffler, the interior wall had collapsed. Installing a new exhaust pipe did the trick. It now runs great.

Your Answer

DeVille

Looking for a Used DeVille in your area?

CarGurus has 1,272 nationwide DeVille listings starting at $1,988.

ZIP:

Cadillac DeVille Experts

  • #1
    kikero
    Reputation
    2,300
  • #2
    Js08016
    Reputation
    2,060
  • #3
    Cynthiasmith
    Reputation
    1,800
View All

Related Models For Sale

Used Cadillac Eldorado
274 listings starting at $2,495
Used Chevrolet Impala
397 Great Deals out of 25,595 listings starting at $799
Used Chevrolet Corvette
101 Great Deals out of 15,518 listings starting at $3,900
Used Chevrolet Camaro
224 Great Deals out of 28,923 listings starting at $3,900
Used Chevrolet Caprice
126 listings starting at $1,350

Used Cars For Sale

2005 Cadillac DeVille For Sale
186 listings starting at $2,297
2003 Cadillac DeVille For Sale
139 listings starting at $1,988

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.