1984 coming back tomorrow
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Joined: Apr 2018
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From: Plainwell MI
1984 coming back tomorrow
Getting my 84 back tomorrow from the shop. A couple small adjustments were made, TPS up about 1/4 volt, Timing bumped to 8 degrees from 4. On a GM OBD1 scanning computer the only thing that shows near out of range is the "block read" or BLM. It is steady at 108. They would prefer it in the 120 to 125 range. Shows it flipping from rich to lean. But the idle is good now, only occasionally dropping to 400rpm in gear then rises back to 700-850. Seems pretty good to me.
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Joined: Apr 2018
Posts: 60
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From: Plainwell MI
had not seen the "block read" number before. Seems like so many things could cause it. When I get it back I will test the MAP sensor just to be sure. Will probably rebuild the injectors over the winter just to be sure they are right. About done tinkering for the summer. Time to just go drive it
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Joined: Apr 2018
Posts: 60
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From: Plainwell MI
well, brought the 84 home today. ran well most of the way. Got down the road about 10 miles, came to a stop sign and miss fire was back. Rough idle. Tomorrow, a complete search for a vacuum leak, test the MAP sensor, and recheck the IAC. Everything else seems fine. Also going to take the plug out of the idle adjustment screw and bump the idle a touch
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Joined: Sep 2004
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From: Mission Viejo CA
Remove the IAC's, and be sure the pintles of the IAC's and the IAC air passages in the throttle bodies are clean. You should be able to see the ends of the pintles by looking down into the idle air ducts in the top of the throttle bodies.
Make sure the iac's are tight and check leaks at the base gasket for the plenum and for the throttlebodies.
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Joined: Apr 2018
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From: Plainwell MI
I pulled the a IAC and cleaned both of them but I will again today. I had not thought about the gaskets between the air cleaner box and the throttle bodies. I don't think mine even has them. That maybe a good thing to get. So the plan today is clean and reset the IAC, test the MAP sensor, and find some gaskets. Thanks
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Remove the IAC's, and be sure the pintles of the IAC's and the IAC air passages in the throttle bodies are clean. You should be able to see the ends of the pintles by looking down into the idle air ducts in the top of the throttle bodies.
If you had a vacuum leak at the base gasket of the throttle bodies, or at the plenum, your idle would be too fast!
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From: Park City Utah