78' running rough???

[mobigly73]

I've been searching through the engine posts and cant seem to find the problem that I have. I just finished doing a timing belt and full tune up in my engine and it seems to run very rough. spits from the carb when you hit the throttle and idle seems rough and unstable. I am still running dual points and all the smog stuff. When you start it it runs high idle for a bit then drops down. If you rev it up over 2000 rpm it seems to drop down to around 1500 rpm for a second then down to idle I'm not sure if that is normal. Also if you pull the wire from the solenoid on the carb when it is idling it dies out immediately (does that mean its working?). Any help would be appreciated maybe it just needs some tweeking or I have something set up wrong. Maybe single points would be better?

[engineerted]

Ok, first thing that come to mind is the timing. Did you set the disy rotor to point at #4 when the timing gears are all lined up? Yes it will run and spit back out the carb, been there done that. Yes pulling the wire from the carb solenoid kills the motor, that is its function.

Ted

[mobigly73]

Yep timing marks lined up dead on and rotor at #4

[So Cal Mark]

sounds like the points aren't gapped properly. Dual points isn't a problem in itself, you're only using one set of points at any given time

[mobigly73]

Ok i will try re gaping the points tonight and see if it changes anything. you think that will make the carb spit?

[Danno]

Ok i will try re gaping the points tonight and see if it changes anything. you think that will make the carb spit?

I'm not the car expert that some of these guys are, but seems to me that the only way a carb will "spit" is when stuff isn't opening, closing, and firing in the right order (or maybe it's better to say "in perfect harmony"). weak spark or no spark shouldn't make a difference. Timing has to be the key.

One question, though, and maybe I missed it in your other posts, but are you running a true dual point system, or are you just firing two points from one wire (this happened a lot because people found it to be an easier fix than making sure the thing advanced on it's own when the car warmed up)???

[mobigly73]

not sure about the points but all the wiring looks factory. As for the timing belt I had the whole motor locked down when I changed the belt and it all still lined up after hand cranking it and after I ran it. As for distributor timing I'm not sure I warmed the engine up and set the timing at 5 deg btdc off the #4 cylinder I'm not too sure if that is right theres alot of conflicting lit about the setting. even the spark plug gap seems to elude me only because the spec says .022-.024 but the old plugs were closer to .040 and it ran good before I did all this maintenance.

[barnesjtsl]

I changed the rotor on my 79 once and had a problem with the screws holding the rotor on dropping down too far and inhibiting the expansion of those little weights (don't know what you call them) that retards (or is it advances?) the spark when the rpms increase.

Might take a look, you never know?

barnesjtsl

[mobigly73]

Re did the points and it purrs like a kitten thanks for all your help!!!

[So Cal Mark]

great news. You do know that you have to recheck the ign timing after changing point gap?

[mobigly73]

Yes I reset the timing after the points now I'm on to the fan switch and hopefully will be on the road by next week. Thanks again for all the help in solving this problem and I should be able to post some pics of my semi finished product soon