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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Jay2D2 on June 12, 2009, 08:05:50 am
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I changed the plugs and wired in my truck the other night and ir ran good for a little afterwards but then it started running rough, almost like an internittent miss but not quite, and then the idle dropped to the point it was barely running and now when I put it in gear she stalls almost immediatly. When I give it gas she rungs good and smooth... the problem just seems to be at idle. I didnt touch the timing or anything on the carb and before the tune up it was not doing this so I dont think its a bad adjustment. I checked for disconnected vacuum hoses and what not but everything looked good.
Now fo rthe truck... its a 1984 C10 with a pre 78 small block not sure 305 or 350 yet. It was originally a straight 6 but was swapped out at one point. I dont know what the emissions components or carb are from. Its a 2 barrel but not sure if its original to the engine or was something newer off another 84 or what.
Any clues?
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Look for arcing plug wires. Check routing for burned wires. Try taking a plug wire off one at a time and notice changes in idle, when you take one loose and nothing changes you found it.
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Wires are all good and I forgot to mention that the plugs were actually changed about a month ago and it was running ok with them before, I tried soaking the wires down with water while it was running and no changes.
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Did you happen to knock a vacuum line loose ?
Have you checked the timing ??
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I have not checked the timing yet however I would be surpsied if that was the problem since it did not hppen before and I didnt touch anything to do with the timing.
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spark plug wire came loose, i bet
Those metal clips have to fit snuggly and you can usually feel it when it clips on the plug, or on the dist. cap. However, they can jump off after a little heat.
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Checked the possibilty 3 times, Double checked them all at both ends then tried undoing them completely and putting them back on... no help at all.
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Retrace your steps and look at everything.
Any one of the new parts may have failed. Cap, wire, plug.
Try disconnecting wires one at a time. Once you find the cylinder, get an old wire and put it on and see if that helps. If it does not, then it is a plug or the cap.
Just start putting your old stuff back on methodically, you might find a couple of wires crossed.
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well if you checked the wires again, I'd next say it may be possible your distributor cap is cracked.....run it at night and see if you see any blue spark where it shouldn't be.
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The cap and rotor wernt changed, they are still the same ones that were there before I changed the wires. I have run it in the dark and sprayed down the cap and wires and it didnt change my problem or arc anywhere.
Its not really a miss but more of a very low erratic idle... could be an intermittent miss but its the low idle giving me the troubles
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Did you do one wire at a time ? or pull em all ? Check the firing order
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Firing order is fine. I have not tried them one at a time yet though.
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See if you can turn the distributor. If it's loose reset your timing. If ok pop the cap off and check inside.
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Distributor is nice and tight, no way it got moved.
When popping th cap off what is it im looking for besides the cap and rotor itself?
I plan on changing the cap and rotor but when I brought the wires home they were out of stock. I dont really think I should change them over just either because Im quite sure the problem isnt one of those 2 pieces. Changing them while looking for something may just cause more headaches
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when was the last time you put gas in it?
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Other than checking everything you did over again there's not much more we can say. It ran good until you worked on it which means it was something you did (unless you just ran it out of gas like irish said lol) or disturbed during your tune-up. I would start over and check everything. And if you are doing a tune up why didn't you change the cap and rotor?
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When I picked up the wires we had to order the cap and rotor but I have them now. I just started with what I had that night. Plenty of good gas in it.
I believe I found my problem, the truck has a manual cable choke but there is still what looks like a choke pull off connected to it with a vacuum hose running to it. I unplugged that and the idle placed itself and the truck runs smooth and wont stall now.
So there is something either with the choke or cpa.
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so since you unplugged that hose did you plug it with something or do you have a vacuum leak now?
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i have a vacuum leak because when I plug the hose the engine tries to stall
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imo i would say fuel problem maybe. i would replace the fuel filter I'm tinking its a quad? so thats no biggie then see were that goes
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Its a barrel and I changed the filter already.
I tend to also be leaning towards fuel problem so as soon as I can I will pull the intake and freshly rebuilt 4 barrel off my 82 k20 and try that.