Hi all, I'm hoping someone out there can give me an explanation. My '64 Acadian Beaumont has a "74 L6 250. I'm getting a rough low idle(fast idle is fine) and a real rich exhaust smell, so I blamed the carb and thought it was time to get a new one anyway. No change. Changed the points, plugs and wires and nothing. Plugs are R45T's with 35 gap.
For some unknown reason, I pulled the #5 wire off and there was no change to the engine while running. I pulled off the #6 wire and the same thing. When I started pulling the other wires one by one the engine would react finally. I checked for spark and it's there. What else could be going wrong?
Any help for a poor crazy man would be most gratifying.
I would check vacuum with a vacuum meter. You could have a bad vacuum leak somewere! Spray oil around the intake manifold and if blue smoke comes out the tailpipe you will need to replace the manifold gaskets!
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1965 Thunderbird Special Landau 10th Anniversary Limited Edition only 4500 built 34,800 miles
So if you have all the wires on and start pulling 1,2,3,or 4 the motor reacts right away?If so you might have a worn out cam or a problem with the valvetrain.
I tried spraying WD40 all around the intake and no luck. I replaced all my vacuum lines as well. And to reply to the wire pulling, 1,2,3,4 have effect 5 and 6 do not. Thanks so far, it doesn't look like an easy fix now.
Compression seems ok.With the valve cover off,look closely to see if all the rockers are moving the same amount.I thats ok I would do a tuneup,cap wires rotor,plugs.
Also check your EGR valve as you mentioned is a 74 engine. When they start failing they open to soon and let a lot of exhaust gas in to the intake to early and run like crap but will run ok at a higher rpm.
I also heard today that maybe my manifold gasket may have a break internally, and in turn, bridge the 5th and 6th cylinders. So I ordered a gasket from NAPA and they are telling me that the 250 only takes one, I thought 2 gaskets were needed. Any ideas?
If you mean the 5th wire is in the 6th position and vise-versa, I checked that already. Compression in the cylinders range from 145-150.
Compression is 145-150 on all 6? I had the same problem once in a 350 Z28; valves were lashed too tight on two cylinders. Readjusted them and solved the problem.
