Engine Missfire Diagnose. - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 04-29-2010, 08:49 AM   #1
Senior Member
True Car Nut
Thread Starter
 
Join Date: Feb 2005
Location: Brampton, Ontario
Posts: 3,014
Thanks: 0
Thanked 0 Times in 0 Posts
Maymybonnieliveforevr is on a distinguished road
Default Engine Missfire Diagnose.

I've developed a missfire under load and varified via the Aeroforce Scan Gauge. I replaced every plug and noticed #4 plug had a slight crack in the porcelain. After the plug change everything seemed well untill a couple days later and again the Aeroforce confirmed the miss. Can the Aeroforce help indentify which cylinder is causing the missfire?
Maymybonnieliveforevr is offline   Reply With Quote
Old 04-29-2010, 08:56 AM   #2
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

The P030X code will tell you, the number of the X is the cylinder. The p0300 is random misfire and not on any one cylinder. Check that plug in the same cylinder. If you see what looks like a crack it may be a carbon trace. If that'* the case, replace your plug wires as well as that plug.
Danthurs is offline   Reply With Quote
Old 04-29-2010, 09:02 AM   #3
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Some Aeroforces do have the ability to show you the 6 cylinders and which ones are misfiring. This depends on the version of the gauge.

You can find this feature by pressing both buttons at the same time and looking for "misfires" in the listing of Scan/Play/DTC'*. etc etc.

If your gauge does not have the feature, it can be sent into Aeroforce for an update. There'* a fee associated, not sure how much that costs these days.
BillBoost37 is offline   Reply With Quote
Old 04-29-2010, 10:10 AM   #4
Senior Member
True Car Nut
Thread Starter
 
Join Date: Feb 2005
Location: Brampton, Ontario
Posts: 3,014
Thanks: 0
Thanked 0 Times in 0 Posts
Maymybonnieliveforevr is on a distinguished road
Default

DANTHURS:

Dan, I don't believe I get a code with the Aeroforce, only the number of missfires, that'* how I verified it is truly a missfire. As for the plug, it was definately a crack since I ran my nail across it and felt it. Usually a carbon trace isn't as deep and has a different feeling. I believe you posted "how to check plug wires". I'll have to see if I can locate that tech info.

BillBoost37:

I've pressed both buttons before and nothing happened, do I need to hold it down for X amount of seconds and wait. At the moment it just states I have around 31 missfires but that depends on how long I run it under load....obviously.

Thanks for the reply guys.
Maymybonnieliveforevr is offline   Reply With Quote
Old 04-29-2010, 10:14 AM   #5
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Frank...no worries. It'* being a finicky if it'* nto popping up the menu. I've texted a local guy by the name of Mick. This guy is an ace with things like this and should be able to help you out in record time.

Please clear an area in the driveway/garage and he'll be home in record time to help out.
BillBoost37 is offline   Reply With Quote
Old 04-29-2010, 10:19 AM   #6
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

New info has been obtained. Told you that Mick guy was quick.

The coil, ICM, plug, wires etc have all been changed a couple times, and the issue always comes back to #4.

At this point, I'd suggest looking over the routing of the wire to ensure it'* not arching or having other issues. Considering how the plug is being changed, meaning from driverside etc and how much torque etc. Consider changing it from a different angle or with a different socket. And....while you are at it.. compression test.
BillBoost37 is offline   Reply With Quote
Old 04-29-2010, 10:25 AM   #7
Senior Member
True Car Nut
Thread Starter
 
Join Date: Feb 2005
Location: Brampton, Ontario
Posts: 3,014
Thanks: 0
Thanked 0 Times in 0 Posts
Maymybonnieliveforevr is on a distinguished road
Talking

The wire does not come in contact with the 02 sensor and I removed the strut bar when changing the plug, as well made sure I didn't overtighten and crack the new plug. The problem went away as soon as the new plugs were installed and came back couple days later.

Mick is presently at work, so that is a priority, next would be modding his car. .

Last edited by Maymybonnieliveforevr; 04-29-2010 at 10:51 AM.
Maymybonnieliveforevr is offline   Reply With Quote
Old 04-29-2010, 10:28 AM   #8
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

That doesn't mean he won't help if I ask him nicely. You know how I can be that way. Plus..he'* loves me. (I know cause he said it about 100 times one night during Beer Pong).

Almost sounds like that plug is fouling out over a couple of weeks. Any oil or build up on it that you want to tell us about?
BillBoost37 is offline   Reply With Quote
Old 04-29-2010, 10:48 AM   #9
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

How does the post look on the plug? You've removed the spark as a problem. That leaves fuel, or mechanical. Try swapping injectors and see if the problem follows. If not, then a compression test. Keep in mind, a compression test may not show if you have a broken valve spring. Seen that twice now. Everything tests good but misfire is still there. Remove the valve cover and there it is, a broken valve spring.
Danthurs is offline   Reply With Quote
Old 04-29-2010, 07:17 PM   #10
Member
Posts like a V-Tak
 
z302's Avatar
 
Join Date: Sep 2009
Location: ohio
Posts: 43
Thanks: 0
Thanked 0 Times in 0 Posts
z302 is on a distinguished road
Default

how do you change a fuel injector?
z302 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Engine missfire code 0304 (fixed) DDay31 2000-2005 4 12-07-2011 08:02 AM
Hesitaion/Missfire under load thesub265 2000-2005 9 10-29-2008 12:46 AM
Missfire problem solved :D Rubix 1992-1999 7 02-23-2007 06:17 PM
missfire captainmiller 1992-1999 7 12-15-2006 10:36 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:54 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.