#3 misfire

**AfterYou** · 10-17-2010, 12:24 PM

I just had a #5 misfire, And i replaced the coilpack.
and now #5 is fixed.

Now its reading a #3 misfire, Once again, i replaced the coilpack for it also, and its still throwing the code and terribly misfiring.

I checked the #3 wire into the back of the engine and i could barelly get my hand back there, but it definitly seems to be snug onto the back.

any suggestions on this?

**sunsetorangess** · 10-18-2010, 03:34 AM

check the compression on cylinder number 3, if its within specs i would check the injector or even swap it with another cylinder and see if the problem follows.
J

**Smittro** · 10-18-2010, 04:15 AM

When you replaced the coils did you clean the pins? Check your grounds and make sure that plug is tightened.. Because of it's location it's easy to think it's tight when it's actually just snug.. Also the small 6mm bolts that hold the coils down are grounds make sure to clean them before reinstalling. Make sure those are also nice and snug.. Corrosion @ the mount, bracket, and bolts can also cause issues.. The non-like metals can cause grounding issues @ the packs too because the base and bracket are also a grounding point..

**Smittro** · 10-18-2010, 04:28 AM

Are you using the windshield washer alot, or has it been raining alot where you are? Could also be a hood gasket seal issue allowing too much water/wheather down onto the packs.... This is what killed mine last year..

**AfterYou** · 10-18-2010, 04:53 AM

Its rained ALOT recently, when it was sitting outside, maybe that was the mail issue? Ill take a further look after school today! thanks guys

**Smittro** · 10-18-2010, 12:12 PM

Originally Posted by AfterYou

Its rained ALOT recently, when it was sitting outside, maybe that was the mail issue? Ill take a further look after school today! thanks guys

? If you mean "main issue" then yes.. I had heavy corrosion @ the pins and up into the pack itself.. Upon removel of the other packs I discovered windwield washer fluid had also been getting into it from dirrectly above the packs @ the hood seal.. I accidently spilled some water over the windshield in the shop and found out it was actually a LOT of water getting past the seal.. Rubber dead blow and some light upward bumps @ the spot welded seam (along the lip where the seal is fixed below the windshield/cowl) did the trick..

**Spaz** · 10-18-2010, 12:24 PM

95 firebird with coil packs or another vehicle??? swap coil packs and see if the code goes to the next cyl... easiest and fastest way to start off...

**Smittro** · 10-18-2010, 12:33 PM

Originally Posted by Spaz

95 firebird with coil packs or another vehicle??? swap coil packs and see if the code goes to the next cyl... easiest and fastest way to start off...

3800 firebird.. 2 plugs per coil..

**Spaz** · 10-18-2010, 12:40 PM

Originally Posted by Smittro

3800 firebird.. 2 plugs per coil..

ah!!! got ya... sorry... io'm always thinking 8 cyl when i hear coil packs...

**Smittro** · 10-18-2010, 12:49 PM

Originally Posted by Spaz

ah!!! got ya... sorry... io'm always thinking 8 cyl when i hear coil packs...

Yeah it's their placement that's the issue

stupid GM..

**79Firebird_99TA** · 10-19-2010, 06:24 AM

Don't ever rule out spark plugs. I was idling at an intersection last week and out of nowhere she starts hitting on 7 cylinders. Had a cylinder 3 misfire. Swapped out the plugs (they had 100k on them)..... good to go!

**AfterYou** · 10-19-2010, 01:56 PM

The wires and plugs are new within the last 20k also

**AfterYou** · 10-20-2010, 05:27 PM

Just bought a new coilpack for 3&6. installed just now, drove, and didnt do a dang thing... well now for more thought

**Smittro** · 10-21-2010, 05:35 AM

Originally Posted by AfterYou

Just bought a new coilpack for 3&6. installed just now, drove, and didnt do a dang thing... well now for more thought

Time to look @ grounds and so forth.. After all your electrical options are exhausted. May want to look into this.. Top one is a new one the bottom are the eaten away (by dexcool) stockers.. Could be starting to get coolant into the combustion chamber..

**AfterYou** · 10-23-2010, 12:09 PM

Took it all apart, looked at it all, looked fine, brought it to a friend of mine who works on motors, and he said it was also looking okay. Any other suggestions?!

**Smittro** · 10-23-2010, 12:40 PM

Originally Posted by AfterYou

Took it all apart, looked at it all, looked fine, brought it to a friend of mine who works on motors, and he said it was also looking okay. Any other suggestions?!

Make sure the spark plug wire is seated all the way on.. Also the boot may have been put on the wire too far durring manufacturing. If the boot on too far up the wire, it can/will leak spark.. This may be masked from sight by the metal heat shield on the wire.. Could be signs of an ignition module failing too.. Check thee injector harness @ the cylinder with the miss, could be loose or the injector could possibly be dieing aswell..

**Smittro** · 10-23-2010, 12:49 PM

The other thing I'll just toss out there is this.. Sometimes a frontal lower intake gasket leak is NOT visible on our engines.. Coolant can run down the front of the motor and onto the front crank sensor. Check it for damage..

What I need here though are specifics..

Exactly.....

1). When and @ what rpm is the miss present?

2). Is it a constant miss even @ idle??

2a. OR does it only miss @ WOT??

2b. Does it come and go??

3). Is there colored smoke presant @ WOT??

4). IF so what color hue is the smoke??

5). Have someone follow you and observe the pipes @ WOT (be safe) and under a load.. They will be looking for smoke and it's color aswell..

**Smittro** · 10-23-2010, 12:54 PM

I forget your mileage?

**AfterYou** · 10-23-2010, 01:45 PM

Originally Posted by Smittro

The other thing I'll just toss out there is this.. Sometimes a frontal lower intake gasket leak is NOT visible on our engines.. Coolant can run down the front of the motor and onto the front crank sensor. Check it for damage..

What I need here though are specifics..

Exactly.....

1). When and @ what rpm is the miss present?

2). Is it a constant miss even @ idle??

2a. OR does it only miss @ WOT??

2b. Does it come and go??

3). Is there colored smoke presant @ WOT??

4). IF so what color hue is the smoke??

5). Have someone follow you and observe the pipes @ WOT (be safe) and under a load.. They will be looking for smoke and it's color aswell..

75k miles
1: When the pedal is pushed more then 1/2 way down, so about 2500 RPMs
2: No, It is only when the gas is pushed more then half way.
2b:Yes, On start up for the first 3 min. of driving or so it doesnt, then it comes.
3:No, there is no smoke
4: see #3
5: Had my step dad follow me and he reported no smoke at all.
However, I cannot go WOT or it will misfire so badly it shakes my whole car

**AfterYou** · 10-23-2010, 01:46 PM

Also when i pulled out of the driveway after it rained a extremely hard shower, and there was a ton of rust where my car was, is this part of a problem? or just because of the raid