Suddenly misfiring! (fixed, dead coil) - 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 02-21-2012, 06:26 PM   #1
Senior Member
Certified GM nut
Thread Starter
 
SignOfZeta's Avatar
 
Join Date: Mar 2005
Location: New Milford, CT
Posts: 2,284
Thanked 16 Times in 13 Posts
SignOfZeta has a spectacular aura aboutSignOfZeta has a spectacular aura about
Default Suddenly misfiring! (fixed, dead coil)

Got out of work and my car wouldn't run. It runs, usually idles, but I can't drive. It can usually hold an idle, but revving it or trying to drive it makes the check engine light flash, along with a severe power loss.

Spark wires are good, but what'* going on? It ran perfectly this morning. I have my sockets on me, but no parts.
SignOfZeta is offline   Reply With Quote
Old 02-21-2012, 06:53 PM   #2
Senior Member
Posts like a 4 Banger
 
Join Date: Nov 2004
Location: bloomington, in
Posts: 122
Thanks: 0
Thanked 1 Time in 1 Post
bobc997615 is on a distinguished road
Default

It could be a cracked coil where the spark plug wire boot clips on.
bobc997615 is offline   Reply With Quote
Old 02-21-2012, 07:22 PM   #3
Retired Administrator

True Car Nut
 
GunsOfNavarone's Avatar
 
Join Date: Apr 2009
Location: Williamsport, PA
Posts: 2,856
Thanked 167 Times in 129 Posts
GunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud of
Default

Couple things to quickly look at:

#1 corrosion between the coil and the spark plug wire

#2 the plug below the oil fill has slowly had oil and dirt get into the heat shield and is causing the wire to fail

You most likely have a failed plug, wire or coil. It only takes a few minutes to check all the coils for corrosion, ensure none of the plug wires came or one of the plug wires are failing.
GunsOfNavarone is offline   Reply With Quote
Old 02-21-2012, 08:11 PM   #4
Senior Member
Certified GM nut
Thread Starter
 
SignOfZeta's Avatar
 
Join Date: Mar 2005
Location: New Milford, CT
Posts: 2,284
Thanked 16 Times in 13 Posts
SignOfZeta has a spectacular aura aboutSignOfZeta has a spectacular aura about
Default

Before I got a ride home, I took a look at a few more things. (Sorry I didn't see this while I was still there, or I'd check the coils and plugs.)

Unplugging the MAF sensor doesn't just make the car stumble, it makes it worse to the point where it barely starts or idles at all.

My flashlight casts a blue light, so I may have the wrong colors. With that in mind, I still don't think the oil is the right color. The underside of the oil cap is yellowish/greenish, and the oil (at 3,000 miles) is a deep mahogany brown — looks nothing like chocolate milk.

The coolant overflow tank is about a half-inch below the full cold line. I didn't think to check the radiator.

I'm thinking my UIM is about to blow again. My mileage is almost twice what it was the first time it blew, so I wouldn't be surprised.
SignOfZeta is offline   Reply With Quote
Old 02-21-2012, 08:18 PM   #5
Senior Administrator








Certified Car Nut
 
Mike's Avatar
 
Join Date: Jul 2003
Location: Horseheads, NY
Posts: 15,643
Thanked 997 Times in 774 Posts
Mike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond repute
Default

If it looks like this...


Then more than likely it is your gaskets going. It all fits together. Low coolant, misfire, crap on cap, miscolored oil. I seen it twice on my car.
Mike is offline   Reply With Quote
Old 02-21-2012, 08:58 PM   #6
Senior Member
Certified GM nut
Thread Starter
 
SignOfZeta's Avatar
 
Join Date: Mar 2005
Location: New Milford, CT
Posts: 2,284
Thanked 16 Times in 13 Posts
SignOfZeta has a spectacular aura aboutSignOfZeta has a spectacular aura about
Default

Quote:
Originally Posted by Mike1995 View Post
If it looks like this...


Then more than likely it is your gaskets going. It all fits together. Low coolant, misfire, crap on cap, miscolored oil. I seen it twice on my car.
The coolant level hasn't changed in two weeks, and the oil doesn't look like the telltale chocolate milk. Does only Dex-Cool make that chocolate milk color (I run green)?

It seems like a UIM failure, but I'm trying to get a list of things to check tomorrow.
SignOfZeta is offline   Reply With Quote
Old 02-21-2012, 09:03 PM   #7
Senior Administrator








Certified Car Nut
 
Mike's Avatar
 
Join Date: Jul 2003
Location: Horseheads, NY
Posts: 15,643
Thanked 997 Times in 774 Posts
Mike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond repute
Default

Besides checking your oil level. If you can pull your MAF screen off, open your throttle all the way and shine a flashlight inside. You might see coolant inside. Another way, disconnect fuel pump fuse and turn it over a couple times, pull a couple spark plugs and see if they are wet.

IF IT STOPS CRANKING! DO NO PROCEED. Hydrolock is possible.
Mike is offline   Reply With Quote
Old 02-22-2012, 12:57 AM   #8
Senior Member
Certified GM nut
Thread Starter
 
SignOfZeta's Avatar
 
Join Date: Mar 2005
Location: New Milford, CT
Posts: 2,284
Thanked 16 Times in 13 Posts
SignOfZeta has a spectacular aura aboutSignOfZeta has a spectacular aura about
Default

I was doing some more Googling, and my symptoms match a partially-blocked fuel filter. I checked over my maintenance logs, and my fuel filter is about 70,000 miles old. Whoops. Think that'* the foremost problem?
SignOfZeta is offline   Reply With Quote
Old 02-22-2012, 11:33 AM   #9
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

Allow me to put a myth to rest. A faiiled UIM syptom is NOT coolant in the oil. Coolant would have to get past the rings to get into the oil from a failed UIM. It'll hydrolock long before you get enough coolant to see a milkiness.

As for your LIM gaskets....you put the aluminum ones in when your cam was done. No worries about them being bad.

Your symptoms are more consistent with a clogged cat or plugged fuel filter (like you posted on FB). If you have a spray bottle, spray your coils while the car is running...you'll know if it'* a coil very fast.
BillBoost37 is offline   Reply With Quote
Old 02-22-2012, 11:55 AM   #10
Senior Member
Certified GM nut
Thread Starter
 
SignOfZeta's Avatar
 
Join Date: Mar 2005
Location: New Milford, CT
Posts: 2,284
Thanked 16 Times in 13 Posts
SignOfZeta has a spectacular aura aboutSignOfZeta has a spectacular aura about
Default

Confirmed that it'* fuel-related. I've got an active P0300, and the long-term fuel trim is up at about 16%. I've got a new filter and some injector cleaner (and non-adjustable wrenches, if any of you remember what happened last time), so I'll try to tear that off today.
SignOfZeta is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Dead laptop, dead iPod, dead life rant wjcollier07 Lounge 24 02-20-2007 07:47 PM
Misfiring Cylinder Problem: Fixed Sully1742 1992-1999 14 05-19-2006 09:11 AM
A//C Suddenly not working malatu 2000-2005 4 07-25-2004 08:00 PM
Sub Dead or Amp Dead? 79ford Audio (and aftermarket electronics) 24 02-22-2004 01:55 PM
Gas Mileage Suddenly Dropped! HELP! toxictelevision 1992-1999 16 03-18-2003 10:57 PM


Tags
coolant leak, misfire, stumbling

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 07:49 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.