My car has A slight miss when you hold the gas steady. I thought maybe A bad plug .Last night I was in my garage and turned off lights ,and looked at the motor running in the dark,the plug wires where arcing at the plug boots pretty bad.They are new cheap AutoZone plug wires .I don't know if the wires are bad or maybe A bad ground on the engine .It has A ground wire from fire wall to the motor,but looks pretty corroded .I wanted to see what y'all thought .
Try some dielectric grease. Pull the boot off the plug, put some grease on your finger and wipe the inside of the boot and stick 'em back on. You need a good engine to chassis and chassis to frame ground, as well as a good battery ground to engine. That helps with several things from ignition, to corrosion.
Not likely. Plugs ground from the wire core to the head. Path of least resistance. But there is a lot of energy, and the arcing is really "secondary" or "stray" voltage that is seeking ground. The grease helps prevent that "air" (moisture) path. Back in the old days, when we first started seeing HEI and CDI systems and the older solid core copper wires, (and them breaking down or breaking), it was a "light show", or if you brushed near a wire or sometimes grabbing the distributor cap to adjust timing, you were "the show". Not the nicest way to find a bad wire, but fun for anyone watching.
Pull and read the plugs as well as inspect them. I had a brand new set of plugs (AC Delco) in my nailhead, and after initial cam break in, I pulled them to read them. One had a cracked insulator tip and very obvious it was firing to the side (ground to head) and not to the electrode, by the coloration on the side of the ceramic and the tip being almost white. You can have a miss for several reasons. Some are listed and can be a "one", "some" or "all". (intermittent "miss" on one cylinder, vs "variable miss" among several or all cylinders.) -Bad plug -Bad Plug wire -Rings -Sticking valve -Leaking valve -Vacuum leak intake or carb gaskets Look for the obvious and easiest (least costly) to eliminate/rule out. But always thinking as we all have been surprised at the one thing we never thought could be the thing that was the cause of the problem. Even bad carb tuning can result in what feels/acts like a miss, and is firing in exhaust, causing a "back pressure pulse" that interferes with low speed/idle "smoothness". So, the more information you can provide, the easier it is to help someone point you in the right direction. (troubleshooting over the interwebs is a challenge all its own...)
Hey thanks for your help. I put A rebuild Q jet on it,and at first it was running rich ,I adjusted it with A vac gauge. The plugs was black after I adjusted it the plugs are A light brown. I kinda suspected one of them might be going bad.Im running A.C. plugs ,Larry told me about NGK plugs.I bought A set ,and plan on installing them ,and better plug wires, using plug grease this weekend and trying that.The miss I have is not that bad,but I want it to run as smooth as possible .
Post back after you make the changes. If possible, change one thing at a time and then test. It helps when you know what fixes the problem, in case you see it again.
I put new plugs,wires, on my car and the little miss was still there. I bought A Sears dwell ,RPM meter at A yard sale yesterday for $5 .I already had one but thought I would try the Sears one.The dwell reading was off I adjusted it to 30° and the little miss was gone.The meter I already had is bad,so my problem was very simple wants I figured it out.
Very good. I always prefered dwell over trying to get point gap correct. Several Fords, and Mercurys always seemed as if the point contacts alignment was off a tad, or setting the gap then tightening the plate or points and then measure again, and darned it it was not exact. (And it just bothered me). Buick and Olds, and allen wrench, dwell meter and 30 seconds, done. It is all about the dwell time. (First time I set them, I actually said out loud, to no one but me and the car; "It can be that easy!"
I got A GMC5500 dump truck with A 292 inline 6 cylinder, you got to set the points with feeler gage,no door on cap.
Yeah, and danged points get "high" spots on one side, and resultant "divot" on the other from transference of contact due to arcing and electron flow, and you had to file then make sure the contacts are aligned and gap them and it just seemed to take about an hour or two to get it right to "drag" the feeler gauge and hope you were not "feeling" them at an angle. That window thing and the dwell adjustment. I hope that engineer got off early that Friday, the week he came up with that.
I got A HEI distributor for my 350 buick,but I like the original look,and I have already curved the points distributor. I don't mine adjusting it ,kinda like doing that kind of stuff .
I'm that way with carbs. I know EFI is almost "Plug and Play", but something about them things with all those holes, and passages and the marvel that they work the way they do.
