Car running like $hit.

[Z51JEFF]

Car started running like its only got 7 cylinders.Could one of the injectors finely has died or one of the coils has died?If one of the injectors died would it store a trouble code?

[Jeffvette]

With the engine running, pull the spark plug boots off the plug. Listen for a change in the engine, and find out which cylinder is not firing. You should hear clicking noise of the coil firing as well. It'll get weaker the further you pull the plug boot out.

[Z51JEFF]

I just checked the plugs wires,no problems here but the car is running right.Go figure.Hey Jeff,can I get that jack bag?

[Jeffvette]

Definitely temp related then, look at injectors or coil. Check it when it's hot.

On the jack bag, yes. You still want that weatherstrip?

[Z51JEFF]

Definitely temp related then, look at injectors or coil. Check it when it's hot.

On the jack bag, yes. You still want that weatherstrip?
When you say weatherstrip do you mean the fender skirt seals?If so yes,Ill take one side if its got the plugs in the ends.Now,will an ignition coil act up if it gets hot?I always thought when a coil goes it just goes.I was going to replace the coils when I did the injectors anyway.I had planned on working on my Nova tomorrow but maybe Ill get the Corvette up to temp and see if the problem comes back.

[tomtom72]

Jeff, usually the hotter an injector and or an ignition coil gets, the worse the electrical issue becomes....it generally is the typical failure pattern.

:thumbsup:

[Paul Workman]

Now,will an ignition coil act up if it gets hot?I always thought when a coil goes it just goes.

Electronics is my livelihood, and in my experience 'lectric stuff often times fails as a function of heating.

The coils on our LT5 are shared between two cylinders. So, if it is a coil failing, then two cylinders would be displaying the same problem, me thinks.

8-5, 1-6, 4-7, & 3-2

So, if it is one cylinder only, then I would put the coil at the rear of the line and look at plug wire, plug, injector, etc.

P.

[Z51JEFF]

Ill replace the plugs.I was going to replace the injectors over the winter if they hold out that long.

[Nick]

So, if it is a coil failing, then two cylinders would be displaying the same problem, me thinks.
That's what I thought, too, until I had only one side of an Accel coil pack fail. The other 7 cylinders were running fine. Good luck.

[Tyler Townsley]

OK to check the coils/wires take a good plug and one at a time swap it for each cyl. Pull the wire, plug in the good plug lay it on the plenum and crank the car. Look at the spark across the plug gap the bad one shoud be evident and if the plug has good fire and it made it no difference you have a bad injector on that cyl.

Tyler

[Z51JEFF]

I replaced the plugs today and drove it with no problems.Im going to figure on replacing the injectors sooner than later.While Im at it Ill replace the coils and a set of new G.M. replacement plug wires.Id like to have a set of original wires but Im not going to pay $400+ for a set of wires,not me.Thanks for all the tips guys,greatly appreciated.

[jonszr1]

not sure if you are interested ,but msd makes a very good set of wires for our cars. very low resistance .

[tomtom72]

Jeff, I have to agree with your game plan.....not trying to spend your $ for ya...but it's the old "while we're here" rule.

Plenum is off for whatever.....do the right thing before closing it up.:thumbsup:

[Paul Workman]

That's what I thought, too, until I had only one side of an Accel coil pack fail. The other 7 cylinders were running fine. Good luck.

Your point is well taken. Your situation brings up an anomaly, for sure. However, the "waste spark" system is a "closed" loop (except for the actual plug gaps). That is to say, there is no "one side" of the circuit, per se', Obviously, by your example, it is possible for a weak coil pack to point out a marginal plug or plug wire situation.

Resistance is significantly higher on the compression side cylinder, so in a "gray" situation it is possible, to have that experience if the plug circuit resistance on one side is unbalanced. I would expect, however, that in most cases both plugs would experience some misfire - trading back and forth, especially under heavier loads.

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/Ignitioncircuit-LT5.jpg

So, that is why I said, I would "put the coil at the back of the line", as far as suspects go: Not to be dismissed, how-some-ever.:icon_scra

P.

[Z51JEFF]

The miss is back,its injector time.Once I find out which is the best injector Ill start rippin.