LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Help finding a miss

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Old 03-18-2012, 11:56 AM
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Default Help finding a miss

I was driving the car on the way to storage 4 years ago and all of a sudden it got a horrible miss. I finished up the drive, parked the car.

Fast forward 4 years; I thought hey maybe it fixed itself. LOL. Nope.

1) All primaries are getting hot, sprayed water evaporates equally fast off them all.
2) all fuel injectors are clicking when listening with a screwdriver one at a time but could one still be stuck open?
3) re-snapped all spark plug wires
4) All fuses good

I'm going to pull all the plugs today. Any ideas? Could a plug to bad suddenly while driving? Wires all look good.

Any help much appreciated.

Here is a video. I tried to rev it up a bit at the end and got some nice smoke.

http://www.cdntechnologies.com/hobby...ning_rough.mp4
Old 03-18-2012, 12:30 PM
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If I understand you correctly, the car started running badly, but then you parked it for 4 years? If so, my first thought would be if you could remember back that far, did you, by chance, just put gas in it before it started acting up? If so, maybe you got a bad load of gas. if so, and it's still in the car, I'd start with a couple of bottles of Techron.

Then I'd look at the plug wires, not just a visual check, but check with an ohm meter, and see if you have a bad one or two. How many miles on the car? Could also be a bad distributor cap, or for that matter, a semi plugged fuel filter....
Old 03-18-2012, 02:08 PM
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Originally Posted by leadfoot4
If I understand you correctly, the car started running badly, but then you parked it for 4 years? If so, my first thought would be if you could remember back that far, did you, by chance, just put gas in it before it started acting up? If so, maybe you got a bad load of gas. if so, and it's still in the car, I'd start with a couple of bottles of Techron.

Then I'd look at the plug wires, not just a visual check, but check with an ohm meter, and see if you have a bad one or two. How many miles on the car? Could also be a bad distributor cap, or for that matter, a semi plugged fuel filter....
Thank you.
I will change the gas and pull the plugs next. You are right maybe a wire went bad while I was driving? I will have to check them all. I will keep you posted!
Old 03-18-2012, 02:24 PM
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any codes? it could be alot of things off the top of my head you need a scanner to find out what cylinders arent firing. but if i had to start blindfolded i would check

plugs
wires
fuel presure
clogged fuel filter
bad gas
opti


and i never ever heard of anyone doing a test by spraying water on the exhaust. to see if its firing. i would think it would be the same temp on all of them
Old 03-18-2012, 03:30 PM
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Originally Posted by Jason94z
Thank you.
I will change the gas and pull the plugs next. You are right maybe a wire went bad while I was driving? I will have to check them all. I will keep you posted!
Good luck!

I was just looking at your avatar...Is your car indeed a '94? If so, even though you didn't mention the mileage on the car, consider that your wires are 18 years old. It is a bit of a hassle to change them, but you might want to put a fresh set on "just because"....



FWIW, I recommend the Moroso Blue Max wires. They fit well, and come already fitted with the number markings on them.



Originally Posted by tt383lt1
.....and i never ever heard of anyone doing a test by spraying water on the exhaust. to see if its firing. i would think it would be the same temp on all of them
That's a "quick and dirty" racers trick..
Old 03-18-2012, 04:04 PM
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I take my temp gun at each cylinder to find the one not up to temp and that is the bad cylinder every time!
Old 03-18-2012, 06:24 PM
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I just fixed a mis on mine. I found worn spots on the wires and those spots were brittle and would crack when you applied any pressure... one was cracked already. The plugs looked okay cept for one that was closed... My car is so much happier now. The wires had looked good until I actually removed them and looked at them closely.
Old 03-18-2012, 08:26 PM
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Originally Posted by tt383lt1
any codes?
I tried the paper-clip AB test and my car doesn't flash the SES light

Originally Posted by leadfoot4
Good luck!

I was just looking at your avatar...Is your car indeed a '94? If so, even though you didn't mention the mileage on the car, consider that your wires are 18 years old. It is a bit of a hassle to change them, but you might want to put a fresh set on "just because"....



FWIW, I recommend the Moroso Blue Max wires. They fit well, and come already fitted with the number markings on them.

That's a "quick and dirty" racers trick..
You are right the wires are probably 10 years old. They are MSD custom fit wires but still maybe I should just change them out.

Originally Posted by notsue
I just fixed a mis on mine. I found worn spots on the wires and those spots were brittle and would crack when you applied any pressure... one was cracked already. The plugs looked okay cept for one that was closed... My car is so much happier now. The wires had looked good until I actually removed them and looked at them closely.
Thanks I think plugs and wires are next and I'll see if I can get to a shop to pull codes.
Old 03-19-2012, 06:15 PM
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Go to an auto parts store they can pull codes too. I have a 93 T/A and my ses light will come on when i turn the key on, but even though i know there is a code it will not light as well, i have never figured that one out, join the club on that one maybe someone will tell us Y?
Old 03-19-2012, 07:58 PM
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Originally Posted by tt383lt1
and i never ever heard of anyone doing a test by spraying water on the exhaust. to see if its firing. i would think it would be the same temp on all of them
Easy way to find a dead cylinder. Spraying water on the plug wires is another good easy test.

Al 95 Z28



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