PCM Diagnostics & Tuning HP Tuners | Holley | Diablo
Sponsored by:
Sponsored by:

Are misfires normal???

Thread Tools
 
Search this Thread
 
Old 04-11-2002, 04:51 PM
  #1  
TECH Junkie
Thread Starter
 
verbs's Avatar
 
Join Date: Jan 2002
Location: At the office
Posts: 3,015
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Are misfires normal???

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ChrisB:
<strong>Do you have an aftermarket camshaft, and if so what are the specs?

Chris</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">No aftermarket cam here. Just bolt-ons.
Old 04-11-2002, 06:18 PM
  #2  
TECH Addict
 
ChrisB's Avatar
 
Join Date: Nov 2001
Location: College Station, Tx
Posts: 2,207
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Are misfires normal???

Do they stay around one cylinder in particular, or are they randomly distributed?

Are you still running stock spark-plugs?

Chris
Old 04-11-2002, 06:38 PM
  #3  
TECH Apprentice
 
TexassTA's Avatar
 
Join Date: Nov 2001
Location: Fort Worth
Posts: 324
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Are misfires normal???

I never got any missfire codes until I put a T-1 cam in.I`ve got an SES light and A-Taped it and it shows no codes.But that was after I ran the car 3 on and off cycles and the light goes away.
Old 04-11-2002, 06:40 PM
  #4  
TECH Junkie
Thread Starter
 
verbs's Avatar
 
Join Date: Jan 2002
Location: At the office
Posts: 3,015
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Are misfires normal???

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ChrisB:
<strong>Do they stay around one cylinder in particular, or are they randomly distributed?

Are you still running stock spark-plugs?

Chris</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">When I added headers at around 10,000 miles I added NGK 55's ...gapped to .5'

I now have 20K miles on the car. The misfires are randomly distributed.
Old 04-12-2002, 12:06 AM
  #5  
TECH Junkie
Thread Starter
 
verbs's Avatar
 
Join Date: Jan 2002
Location: At the office
Posts: 3,015
Likes: 0
Received 0 Likes on 0 Posts

Default Are misfires normal???

My car is now finally in perfect tune. Perfect Ltrims (never above 0%) and perfect o2's (.88-.89) <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

However, I'm still getting misfires and was wondering if this is normal. I don't get any KR either.

Somehow atap is showing that I'm getting misfires in most of my cylinders!!! How could this be???

All I have are bolt ons for mods, and I'm maybe thinking injectors are bad, but I only have 20K miles on it. I am running 62psi fuel pressure which may add some load to the injectors. I dunno.

Any suggestions???

<small>[ April 11, 2002, 06:41 PM: Message edited by: verbs ]</small>
Old 04-12-2002, 12:48 AM
  #6  
TECH Addict
 
ChrisB's Avatar
 
Join Date: Nov 2001
Location: College Station, Tx
Posts: 2,207
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Are misfires normal???

Do you have an aftermarket camshaft, and if so what are the specs?

Chris
Old 04-12-2002, 09:22 AM
  #7  
TECH Senior Member
iTrader: (7)
 
Ragtop 99's Avatar
 
Join Date: Nov 2001
Location: Bethesda, MD
Posts: 9,491
Likes: 0
Received 1 Like on 1 Post

Default Re: Are misfires normal???

do you get a lot or a little? Can you feel shake in the car at idle?
Old 04-12-2002, 10:48 AM
  #8  
TECH Junkie
Thread Starter
 
verbs's Avatar
 
Join Date: Jan 2002
Location: At the office
Posts: 3,015
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Are misfires normal???

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ragtop 99:
<strong>do you get a lot or a little? Can you feel shake in the car at idle?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hell yeah I feel the car shake at idle....between my headers, true dual exhaust, no cats, and the exhaust dumping before the rear axle I get a decent amount of shaking....

I don't get a ton of misfires, at idle when I look at ATAP using the cylinder misfire history for each cylinder, I get up to 5 misfires in some of the cylinders in a minutes time or so...

the other wierd thing is when I'm recording atap runs, I have a category for total misfires. When I start recording, that number right off the bat will start at 8 or 12 or something high.

But as atap is logging more data while I'm driving, that total misfire number drops in 2's....to 6, then 4, then 2, etc...

<small>[ April 12, 2002, 12:42 PM: Message edited by: verbs ]</small>
Old 04-12-2002, 02:43 PM
  #9  
TECH Regular
 
Sparky's Avatar
 
Join Date: Nov 2001
Location: Clarkston
Posts: 499
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Are misfires normal???

We're talking about the mis-fire current for each cyl, right?

This parameter records the number of "misses" out of the last 200. Anywhere up to 10-12 is very normal in my opinion. Try sorting your data by PRM and deleting anything below 1K rpm. What does it look like in other RPM ranges?

Mark
Old 04-13-2002, 12:14 AM
  #10  
TECH Regular
 
Loco's Avatar
 
Join Date: Nov 2001
Location: San Antonio, TX
Posts: 455
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Are misfires normal???

I get random misfires too. But I think its my TR 6 plugs. Not sure tho. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />




All times are GMT -5. The time now is 05:39 PM.