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Discussion Starter · #1 ·
I think I know what my problem is, but, wanted to get other opinions. I was having carb problems (I thought) so I switched to a spare weber. As it turns out, that was not the case. The car starts and runs great, actually gets better mpg than the original carb, but, when you accelerate hard, such as passing, or on a entrance ramp, the motor wnts to go, but, it's like an invisible hand holding me back. If I back off the throttle just a bit, it picks up a little, but, not much. I think this is the advance weights not doing their job. Am I correct?
Gene
 

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Solo II is fun in a GT!
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Not sure. What about the vacuum advance,
or vacuum line? How old or craked is the vacuum line? Have you got grease on the Dist. cam lob? Points look OK?
Yes it could be the advance weights.
 

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I was having a similar problem, the vacuum retard was 1/2 unscrewed from the distributor.

Maybe check that if yours came with a vacuum retard.

Hope it helps,
Sean
 

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Gene,

If you aren't getting enough ignition advance (either mechanical or vacuum advance), you will lose power at full throttle. But it just doesn't "feel" like an advance problem. As if I can tell how it "feels"! But to be sure, you can check it by borrowing (or renting) a timing light with a timing advance dial indicator feature. The specs for the various years are listed in the FAQ section (thanks to RalllyBob) under:

http://www.opelgt.com/forums/showthread.php?s=&threadid=360

Just check the mechanical advance at various rpm without the vacuum advance connected, then re-connect the vacuum advance, and check it again at full throttle at 2500 rpm, which will give you total advance. If you have access to a vacuum guage and pump, you can actually check the vacuum advance separately from the mechanical advance. My '71 and '72 manuals state that the centrifugal advance should start at 1100-1200 rpm, be 7.5 - 15 degrees at 1400 rpm, and be at a maximum of 28 - 32 degrees at 3600 rpm. Vacuum advance should start at 5 inches of vacuum, and be 7 - 10 degrees at 5.6 - 6.4 inches of vacuum, with a total advance of 43 - 55 degrees at 2500 rpm.

I would also look for a couple of very different possible problems.

The first is ignition. A weak spark (bad plug, overly resistive wires, carbon-tracked cap, arc'd points or bad coil) will often manifest itself in a similar way. Works fine as long as you don't give it too much load, but open up the throttle, and the increased ionization load will cause one of the components noted above to cause a mis-fire. Or a LACK of fire.

Or, for something completely different, check out your fuel pump. At less than full throttle, everything is fine. But try to deliver more fuel to the engine than the pump is putting out, and the bowl level drops and the carb leans out. I don't know what the flow spec for a stock Opel mechanical fuel pump is, but according to the manual, the outlet pressure is a good indicator of pump condition. And it should be 3.1 to 3.7 psi, which you can check with a vacuum/pressure guage at the carb inlet.

HTH
 

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Discussion Starter · #5 ·
Keith;
There are a couple of ways you can be right on what ideas you have given me. I have done very little to this Wagon since I have bought it (mechcanical wise) other than a clutch, I have not touched this motor. I did the carb swap recently, because, the secondary would stick open if you accelerated too much. I changed the carb out to see what difference it would make. It has made a dramatical difference. The performance is better, but, has far more room for improvement. But, it did point out a few other problems that were compounding each other. As I have drove the car this week, with just the swapped carbs, it gets better as time goes on, but, that "hold back" feeling is there, just not as pronounced, but, still there. I will pull all the plugs this weekend and possibly get a new set of wires and clean out the dist cap, as well as, cleaning the rotor button. I'll also check the vac advance just as well. It'll all probably just mere neglect that has been the problem. But, I'm going to keep a better check on it from now on.
Gene
 
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