forgive me if this is the wrong section, i'll be lucky to get a reply anyways. o No: i have a buick 350 with accel wires, when i first got it, it ran great, it still runs pretty good, but once in a while i get some hesitation and feels like i'm missing a cylinder. i always let it warm up before i take it out, and tuned the carb and got rid of the problem so i though. the breather will spit a little oil after running a long highway trip, and my number 5 and 7 plug wire were pretty oily, the rest are dry, i cleaned them up but was told that the oil can vaporize and cause arcing, makes sense i guess. so to test the moist plug boots to see if they were the culprit, i pulled them off the cap, one at a time. the strange part was, the motor didn't stumble any more or less with the wires off, so i figured i had found my culprit... but then to test my hypothesis, i pulled a plug from the other side... still, it ran the same, it got to the point were i had my number 1, 5, and 7 plugs off, and it didn't run any different. PLEASE HELPo No: o No:
Sounds like a tune up is in order, check the condition of the cap & rotor, spark plugs. Does it still have a points distributor? Also was it arcing between cap and wire as you pulled them off? Keep it simple at the start!
i just put in fresh plugs, and yes, each wire i pull off the cap arcs at that point. i know the cap + points have been done within the last 20-30k miles
why is it intermittent then? this will be lousy if it's a head gasket or cracked head, because the previous owner did the head gasket and valve seats, the only reason i believe this coming from someone selling a used car is because he has picture documenting it
X3 You could have a bent pushrod, broken lifter, etc. I have in the past, and seen exactly those symptoms.
Test the wires with an ohmmeter - even a new wire can be bad. Replacing wires without this test is just throwing money away. My lawn mower spark plug is 20 years old; those in my Buick are 17. They rarely go bad unless YOU break them or detonation destroys one. The last set of plugs I took out from my '96 F150 had 90k miles on them, still fired fine, but the side electrodes were incredibly eroded (there was perhaps 30 percent of the electrode remaining). It was surreal to see them so shot and know that the engine still ran perfectly.
a couple questions/clarifications: what should the resistance be? also, with knowing the heads had been off in the last two years, and not hearing any knocking, tinging, pinging that would indicate bad pushrods, lifters, rockers, is it still very likely? also, this "missing" was noted by the old owner, and wasn't present when i started driving the car, i've had it less than two weeks but have driven it every day, the the symptoms just started the other day
Josh, if any damage happened, even in a small window of time, testing should show it. Regardless of the fact that some work was done by the owner, there's no way to verify the quality of the work or whatever other problems may have crept up other than to test everything you can. If tests show nothing, then it's logical to inspect parts. Don't look at testing as a bad thing, it can help you rule out things so you can spend time looking elsewhere. Devon
This is funny. Save up a few bucks, find a local shop with a mechanic who is familiar with old cars, and pay him to fix it. We can tell you 20 ways to Sunday what the problem might be, but from the looks of it, 19 will be wrong. Could be as simple as bad gas, could be as bad as a worn out cam. I would suspect those accel wires are the main source of the problem, but all the basics gotta be set up right. Points, timing, choke, idle mixture, etc, before you want to condemn anything major.
According to the Chassis Service Manual, OEM wires from 40 years ago would have had about 2,000 ohms per foot. The longest wire should not show greater than 20,000 ohms total. I've had a wire reading infinity that would still fire up to about 3000 rpm and then cut out because cylinder pressure was then too great to allow the spark to jump. On a lower compression engine that wire was asymptomatic. I've seen pushrods so bent that the valve would not actuate; the cylinder read zero compression; the plug was fouled; there was no external noise as an indicator of the bad components. In such a scenario you'd pull a plug wire and notice no difference in how the engine runs. Pulling your valve covers is a quick and inexpensive way to inspect the mechanical actuation of the valvetrain and at least eliminate most of those possible issues. Given your experiences over two weeks mechanical issues are probably the least likely. But quick inspection of the valve train does not take much effort. Regardless, standard tune up procedures on 40 year old cars include compression tests. Rather than spend hundreds on ignition parts, first at least confirm you have compression. Other than what I've mentioned above, the things I've discovered over the years (on Buicks now 40 year old) causing some of your symptoms include worn-out distributor bushings allowing the distributor shaft to float around in the housing and change dwell/timing (once the engine got hot this was particularly pronounced as the shaft floated around even more); I've found an end of the coil lead to the rotor with a burned end.
I recently went thru similar problem. Pulled the plug wires one at a time at the distributor cap. When either of 2 of the wires were pulled the engine actually sped up and ran smoother; when any of the other 6 were pulled it slowed down and ran rougher. Culprit was a bad distributor cap--internal arcing between 2 terminals. Start checking the stuff that is cheap/easy to fix and work up from there!
No visual evidence in the cap! In my case, Chrysler 318 in a boat, the engine had a strong miss at idle, seemed OK when revved up with no load, but would not get up to speed under load. I initially overlooked the distributor cap because it was almost new and there was no visual indication of a problem. When I started pulling wires one at a time at the cap and found it actually sped up and ran smoother when either of 2 adjacent wires were off it became clear what the problem must be. The 2 cylinders in trouble were located opposite one another and I think this made the situation worse. John :beer
i finally pulled the cap, no carbon tracking, but it was oily, until i can get a new cap + points, or upgrade to electronic, i just cleaned it with a clean rag, and cleaned the points, and my problem's gone for now, it actually runs better than it had since i got it.
