VERY lean on acceleration

[Kudzupatch]

Actually it is over 13, I was just rounding. I don't remember exactly number but it was close to 14 volts. Same as what I saw at the battery.

Just putting in the plugs right now so can't check it.

[Kudzupatch]

double post

[ChevyTech]

I agree with speedy that 13 volts is to low.
13 volts is not ok.
13.8 volts is ok.

It sounds like you could have a bad spark plug wire.

Plug wires can have the correct resistance and still be bad. A common plug wire problem is a leak in the boot on the spark plug end allowing the spark to jump to the heat shields on the exhaust manifold.

If the wires are swollen from oil getting on them, replace them. Don't go cheap on the plug wires.

You could watch it run in the dark and look for sparks.

You could take a spray bottle to it and see if a little water makes it misfire.

Small dancing sparks, with it wet, in the dark, are normal.

[Kudzupatch]

Originally Posted by ChevyTech

I agree with speedy that 13 volts is to low.
13 volts is not ok.
13.8 volts is ok.

It sounds like you could have a bad spark plug wire.

I will double check but I am sure it was at 13.8 volts. It was the same as the battery voltage running.

Funny you would say that about the wires. I keep looking and I found one with a short. I was checking the ohms again just desperate to find something and had trouble with the #8 wire getting a reading. I discovered that it had a bad connection, I can wiggle the wire and loose the connection.

Plus the #8 plug had a different color than the others, it was darker, had a darker gray discoloration on one side where the others would have been tan. I appears it has in intermittent spark of as you said, it is shorting out to something. These are new wires, just a few months old and were not cheap wires. But with ascso many replacement items obviously not well made.

Now, suggestions on a good brand of wires? I typically order from Summit or Jegs.

[ChevyTech]

I have not bought any plug wires for several years.

Everything I have used in the last 25 years has been OEM.

I have seen new cheap wires that were only 7mm and giving trouble.

Make sure you use the grease on the ends when you install new wires.

[Kudzupatch]

It 'APPEARS' I had a bad spark plug. While I had them out to do the compression check I decided to out in new plugs. Other than the odd color on the one with the bad wire there was nothing obvious wrong. Rough idle is gone and that random misfire is too. But it has behaved before and started back after a few weeks but I am trying to be optimistic.

I have a show to attend next weekend and I don't think I will be able to get wires and install them before I leave. But that is next and hopefully the Gremlins will have be Exorcised!

[Kudzupatch]

Just a follow up for anyone that might do as I have done and read all the old threads. I took the boats to a show and put 1,400 miles on her and on the trip. I did not get time to replace the wires, just the plugs. About half ways though the trip I started to notice the miss at idle coming back but not near as bad. This is exactly how it did in the past.

Now back at home a buddy gave me an old set of wires he had saved. We went through them and found one the right length and checked good, so we replaced the suspect wire. The miss appears to have dissapeared and runs good. Looks promising that all this work has finally paid off! And that is the second time a new(ish) part has turned out to be bad.

[68 TT]

Originally Posted by Kudzupatch

New GM EGR, learned that lesson! But I was thinking about plugging it since it is the newest item and just seeing what it did.

Funny, it is a Bosch 02 sensor. I take it they have a bed reputation. As bad as aftermarket EGRs?

Speedy, O2 reading bounce around normal, except on light acceleration. Runs fine down the road. When it looses power you see the lean condition from the O2 sensor and that is only under light to moderate acceleration and then it not 100% of the time.

I just picked up an ACDelco AFS21 GM Original Equipment Oxygen Sensor off of Amazon for $13.33 shipped. Considering that the crappy Bosch is $20 at the local auto parts stores this is a pretty good deal.

[ChevyTech]

I always like to see updates on threads.

I do wonder how things go for people I help, as well as other threads of interest.

Thanks for taking the time to write an update.

It is very sad the quality of replacement parts has gotten so bad.

[Kudzupatch]

Originally Posted by ChevyTech

Thanks for taking the time to write an update.

You are welcome. In the search for this I have read a lot of threads and only one of two ever followed up and said it fixed my problem. I hate that.

It is very sad the quality of replacement parts has gotten so bad.

I was going over this in my head last night making a list of all the NEW PARTS that I had to replace again. All of these were just a few months old.

Ignition module (part of a rebuilt distributor)
Spark plug wires
TWO distributor caps
Bosch O2 sensor. To be fair after I learned about their reputation I replaced it before it gave trouble

[OutlawDrifter]

glad you got it tracked down.

i'm to the point i shop on rockauto.com and amazon and buy strictly ac delco or delphi parts. their QC is much better, and i would rather pay a little more (still less than cheapies at local parts store) and be running than chasing problems.

[Kudzupatch]

A quick follow up. The miss returned after another road trip. It actually got to the point it was an off and on skip but only at idle. Almost would go dead at one red light and then run fine at the next.

When we got home I popped the hood and I head the idle drop but this time I heard an electrical spark and traced the sound to near the plugs.

New set of AC Delco wires solved it. Now, except of a bit of roughness when it first starts up it runs like new! Took a long time but I finally have it running right.

Lessons learned,
Use OEM parts!
Be patient and test, test, test! Don't through parts at it blindly.

[speedygonzales]

http://www.federalmogulmp.com/en-US/...0Flashover.pdf