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I have an 82 n/a and I can't seem to get it running right. I adjusted the valves, have a new fuel filter, new injectors, and tp sensor. I changed the distributor with one from an 83 n/a and adjusted the timming. The problem with the car is that when its parked and I turn it on it idles fine and when I accelerate it revs good. But when I take it out on the street and accelerate, and the rpms reach 3000, it starts to hesitate and has no power. I have to shift to the next gear and it will be ok, as long as I dont punch the gas and reachs high rpms. The weird thing about it is that when I was adjusting the timming with the gun and accelerated the timming would retard first and then advance. I know this is not right and as the acceleration advances so should the timming. I know this is a problem and need help on isolating the problem parts. Could it be the head sensor, air flow meter, water temp sensor, ignition module, cpu? What controls the advancing and retarding? Please help need to smog in CA by 31 of october!
 

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Re: adjusted timming and still ignition retarding?

Distributor controls these functions. You may want to pull yours out and give it a good going over.

By following the FSM, you should have no difficulty disassembling and troubleshooting the unit.

Basically, When you step on the gas, your manifold vacuum increases, which should activate your vacuum advance module. This slightly advances your timing, to give you umphh off the line, and prevent stumbling.

This advance goes away quickly as the engine starts to equalize the manifold pressure. Then your mechanical advance takes over. The mechanical advance is a device made up of weights and springs, and is just under the breaker plate of the distributor. These work by centrifical force. As the RPMs increase, the force on the weights begin to overcome the tension of the springs. It is set up so that when the weights move farther from the shaft, the points/contact advance. The amount of advance is dependant on the weights and springs. The more weight you have, the faster it kicks in, or the stronger the springs, the slower it kicks in. Mechanical advance is set to stop advancing at a certain rpm (don't have the figures handy).

So, when you gas it, VA gets you off the line, and then fades out, and MA kicks in and carries you to top end.

I would make sure that the VA is actually working. These units fail, as well as the vacuum lines that supply them. If it seems that your total advance is also not functioning, look at your mechanical advance. These parts should be free of rust, and greased.
 

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Re: adjusted timming and still ignition retarding?

Also make sure to check the throttle enrichement switch, a bad connection will keep you from reving past 3000 rpm under load. Its on the side of the throttle body and has a 3 wire plug connecting it. If you wash your engine, water will get in this connection and the car will run like crap not reving past 3K.

Matt
 

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Re: adjusted timming and still ignition retarding?

Like the other guys - vacuum advance, but with a twist. You'll NEVER get it to run right until you make sure the throttle plate is closing COMPLETELY at idle. If the throttle plate isn't completely closed, you have vacuum advance at idle, no matter how you adjusted it, going retarded when the throttle is opened.
 
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