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Discussion Starter #1
Hey guys,

my 97 Silverado has 106.000 miles on it & there seems to be a miss going on with the engine.

I just installed new plugs, gapped them to .060", still has a slight miss @ idle. The engine shakes just a bit @ idle.

All the old plugs looked good, gap might have been opened up a bit from when I installed them (errosion) but they looked good.
New plugs helped the mis just a tad over the old plugs.

I never have changed the cap or rotor or plug wires.

I have them all , just going to install them sometime this week.

Was wondering if there are any common problems with these trucks that would cause this type of miss/shaking of the engine?

Like a fuel injector problem, mass airflow sensor, other sensors?

I had a check engine light CEL a couple years ago & the scan tool said it had a misfire on # 3 cylinder.
Later, several months later I had another CEL, scan tool showed it had a # 6 cyl misfire.

Both times I had those CEL's the engine ran pooly for a few miles, then it cleared up & ran fine.

Any ideas would be great.

Thanks
 

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I had a 98 for 130,000 and never had a miss except for one time I got some bad fuel. Of course that showed misfires across most cylinders, not just one. If you've got good plugs, that was probably the easiest and best place to start. Changing the cap, wires and rotor wouldn't hurt since you have them. The rotor is not likely a problem since your issue is isolated to one cylinder. You could have a bad/dirty contact on the cap or a wire issue. You can check the wire for resistance easily enough.
The only issue I can recall a friend having that might not be routine maintenance related was a fuel injector. Of course, if the truck had issues before, it could be internal - valve, etc.
I'd recommend trying your maintenance item and some good fuel system cleaner before I got too stressed.
Best of luck to you.
 

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106,000 miles is a lot of miles on the original cap/rotor.

I was having a miss at low throttle when cruising, new cap and rotor solved it. The contacts had a whitish build up on the contacts. I got a $15 cap/rotor with the good brass contacts and metal sleeves where thehold down screws go.
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I suggest you reuse the screws that hold teh cap on the distributer body. If you use teh new supplied screws, teh new sealant on them will strip the plastic tabs that hold the cap down.
If you strip the 2 hold down tabs, you will need a new distributer or this product which works great as its steel.

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022_zps3e9c5be6.jpg


peace
Hog
 

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Hogg makes a good observation to point out about the small torx head screws that hold the cap. Don't use a ratchet! They just screw into plastic and will strip very easily - we're talking inch-pounds, not foot-pounds when tightening!
 

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Discussion Starter #5
Just an update guys.

I replaced the injectors with the newer style ones & now it runs great!:)
I noticed the fuel pressure regulator was leaking fuel which was causing the engine to load up with fuel.

So I think that was the real problem, not the injectors, but since I was doing all the work taking it apart I figured it was a good time to change the injectors to the better ones anyways.

Now, the transmission is taking a dump.:mad:
 
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