problems with a miss

[maxlsv8]

I got 01 LS V8, a few weeks back it started having a miss. I plugged in a code scanner and got codes for: random multiple missfire, and cyl. 3 missfire.
So I changed the plugs with NGK iridiums, and replaced the 3rd coil. The miss is still there, Only when you apply the brake and put it in D5 and reverse. And sometimes when its under 40-50% steady throttle. Now the CEL is gone after changing the coil. The miss is not real bad, but just enough to get you agrivated. There is no chance of me installing the coil in the wrong cylinder, I didn't damage the plugs when putting them in, the coil is possisioned correctly, I used dielectric grease on the ends of all the coils when reinstalling them. Today I listened to the engine and I hear a whisstle, so it could be a vacuum leak. I looked over everything really good and could not trace it. Is there any common areas where the vacuum leak could occur? I'm also going to test my battery and check a few other things, but I think that its a vacuum leak for sure. And on the side note: I've had more problems with this car then any other cars that I've ever had, and this car only has 80k mi.
and I would like to personally beat the crap out of the enginner that came up with idea of hydraulic cooling fan, because I had to repair it 3 times, because first the collision shop didn't use the right fluid and froze it up. Sorry I'm just venting

 

[NateRW21]

Well, best way to find a vaccum leak is grab yourself a can of starter fluid and start misting down all of your vaccum lines. You'll know when you find the leak!

 

[StinkinLincoln00]

maxlsv8, you are on the the right track. I am having an almost identical problem with my 2000 V8. I am showing a mis in 1,3,4 and a high circuit problem with my AIT sensor. I have replaced the spark-plugs, 2 coils, fuel filter and had it scanned 3 times. The CEL is STILL on...vaccum lines are the only thing left.

 

[eL eS]

The misfire issue is a pain in the @s$ to fix and found that it is easier to just replace all of the coils. It is a little more work and slight overkill but very often the misfiring coil is often misidentified which means more trips into the engine.

But another thing to consider would be the fuel injector. If the injector goes bad then atomization of the fuel fails to take place which leads to a firing anomoly.

Do a search on fuel injctors and you might come up with some good leads. I have the autoenguinity scantool for my laptop and the 00 shop manual but I am going over to Orlando today for my wifes birthday.

If you want to meet up next weekend to see if we can find out what is going on send me a PM with your number.

 

[dtangerini]

My 2000 V8 began to skip & hesitate about 6 months ago. I have found the problem and maybe yours. It is the ethanol in the gas! Start using premium grades and the problem will probably go away as mine did.

 

[JES_LS]

My 2000 V8 began to skip & hesitate about 6 months ago. I have found the problem and maybe yours. It is the ethanol in the gas! Start using premium grades and the problem will probably go away as mine did.

Why do you say start using the premium grades of gas.
First of all you should have been using premium from the start (91 octane or more).
Second in this area the premium grades have more ethanol than the regular grades at the stations that admit using ethanol and the oxygenators.

 

[NateRW21]

Does anyone know about what the adverage HP increase is (03 V8 w/cold air)? That and some HID fog lights is really about all I have left to do. (and that magnaflow if it ever comes out for the 03)

 

[NickLS]

Well, best way to find a vaccum leak is grab yourself a can of starter fluid and start misting down all of your vaccum lines. You'll know when you find the leak!

Nate, Can you explain alittle more on this technique? I'm very interested in trying this. W/ 85,000 miles on the car, and as much to my knowledge I'm still on original hoses and lines. This would be a nice test for me to do.

Second in this area the premium grades have more ethanol than the regular grades at the stations that admit using ethanol and the oxygenators.

That's True. Most of the gas stations here (around houston, tx) have ethanol added. Some even say (10% Ethanol) posted on the pumps. Anyone know of gas stations that don't have ethanol blends? We've got Exxon, Shell, race Track, etc..

 

[eL eS]

Make sure you do this in a well ventalated space. With the spray all you have to do is spray in the area you think you hear the vacuum sound or suspect a vacuum leak but do not go crazy becasue the stuff is highly flamable. Just try to focus the spray on a small area this will help pinpoint the line.

Listen for the idle to pick up after you spray. If the idle increases you have found the leak. Also, try to stay away from the intake with this stuff. If the intake picks it up then the idle will certainly rise.

Nate, Can you explain alittle more on this technique? I'm very interested in trying this. W/ 85,000 miles on the car, and as much to my knowledge I'm still on original hoses and lines. This would be a nice test for me to do.



That's True. Most of the gas stations here (around houston, tx) have ethanol added. Some even say (10% Ethanol) posted on the pumps. Anyone know of gas stations that don't have ethanol blends? We've got Exxon, Shell, race Track, etc..

 

[dtangerini]

The problem could be fouled injectors, put in a good fuel injector additive, this will clear up the problem, it worked for me.

 

[ksbga]

Name change?

The problem could be fouled injectors, put in a good fuel injector additive, this will clear up the problem, it worked for me.

Dtang , This is like the 4th post I've seen you advise the additive..
You HAVE to change your name to something with injector , and additive in it!
Just a funny observation here. LOL.
The stuff does help a bit tho (no such thing as mechanic in a bottle)
Just don't use it more than a couple times a year , too much IS a bad thing!