Hey as I said in an earlier thread the /6 225 in my 73 duster was running shaky. We found the problem today but we don't know whats causing it or what to do. My cousin who is a mechanic took a hose off of the EGR (?) valve and the engine started to run smooth. He said it was running shaky cause the hose taht shudd only have vacuum when the throttle was pushed had vacuum at idle. He said it could be a vaccuum leak or something. Also the fuel mixture and idle screws on the carb could be turn until they are tight without it stalling like he said it shudd stall the engine. It evenm didnt stall when the carb was was completley covered.

So.. do any of you have or know where there is a vacuum diagram of a 225 /6 from 73 that i can use to trace the leak or see if hoses are hooked up right?


thanks
and sorry if i bor you wiht my not knowing anything about nuthing

The obvious places are all the hoses and connections, including the manifold bolts, but don't forget the power brakes, cruise control, or the possibility of a porous aluminum intake manifold. Also check for dried out caps on any unused vacuum sources on the intake or carb.

I'm a little bit confused over what your cousin said about the EGR valve. If you remove the hose at the EGR end and cover the end of the hose, the idle should improve, if you have a bad valve. If you leave it uncovered, it invites a bigger vacuum leak. If your idle is set correctly, you shouldn't have vacuum at the EGR hose, or very little at the most.

You might check to see if you have the hoses connected properly at the carb.

One of the experts will surely correct me, but I don't recall there being an EGR valve on a '73 slant...??

One place to check in on the #6 intake runner where you might have a "vacuum connection tree"; that's where I found my leak...

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FullTime RVer in a 1991 Scamp 13' pulled by a 1982 D150 /6 BBD A833/OD 3.91-posi

If the idle smoothed with the EGR vacuum hose pulled and still open, this doesn't sound like a vacuum leak to me. Sounds like the EGR is active
when it should not be. If I remember my engine class correctly - At Idle and cold operation the EGR on most systems should be turned off to
prevent a rough idle.

I do not know the mechanism on the slants - my dodge colt 1468 cc
4 cyl had a temperature activated vacuum switch that kept the EGR
from getting any vacuum until after the engine was warm.

Back to the vacuum leak - if the idle smoothed when you plugged the hose you took off the EGR - the place I would look for a Vacuum leak is the EGR diapham.

Yes, the 73 does have a EGR valve. The egr valve in under the aircleaner on the intake manifold. I have a 73, wish I didn't have it. I've been having rough idle with the EGR valve disconnect, but I didn't plug it, that was probably my problem since it idled well after re-connecting it.

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My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.