'93 Regal Stalling & Rough Running - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Buick From the Electra, Lesabre, Park Avenue, Regal, to the Grand National. Here's the place for all things "Buick"

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 05-12-2015, 03:02 AM   #1
Junior Member
Thread Starter
 
Join Date: Jun 2011
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
hadaford is on a distinguished road
Default '93 Regal Stalling & Rough Running

My 1993 Regal 3.8L runs great for about 11 or 12 miles. After that, it starts running rough and stalling. It throws a code 18 and sometimes, if I keep trying to drive it, a 42. Once while in a drive-through, I tried to keep it running by feathering the throttle, and the cat heated up and burned off all adjacent oil.

After it sits for 5 or 6 hours, it'* good for another 12 miles. It gets me to work and back home, but anything else, I'm out of luck.

I've been working on the assumption that something is heating up and failing, then is fine after it cools down. This has been going on for months! You would think it would have failed permanently by now, but the run time hasn't even shortened.

From what I've been able to find, the OBD1 code 18 for '93 3.8L is for the Cam/Crank sensors & circuits.
Code 42 is for Ignition control circuit/Electronic spark timing.

I've replaced:

Cam sensor & pigtail

Crank sensor & pigtail

All 3 coils

ICM and harness

TPS plug

ECM

Ignition switch

Harness wires between ICM, ECM and the crank & cam sensors. (Soldered & heat shrinked to within 4 inches of ECM connector.)

The hot in run, test or start wires from the ignition switch to the Right Side underhood elec center and to the fuse block by the glove box.

All of the fuses, just because.

The 3 cooling fan relays in the R/H underhood elec center.

The fuel pump was replaced about a year ago.

I'm at my wits' end with this.
HELP!!!
I may have to revive my '68 Econoline!
hadaford is offline   Reply With Quote
Old 05-16-2015, 05:34 AM   #2
Junior Member
Posts like a V-Tak
 
Join Date: Mar 2015
Posts: 27
Thanked 2 Times in 2 Posts
swl2001 is on a distinguished road
Default

Have the exact same car and had the exact same problem (no code 42 but same symptoms and code 1. Have you tried replacing the spark plug wires? I kept screwing around with all the signal stuff but it ended up being a very small arc from the boot to the ignition coil. My mechanic said to mess around with all the wiring and such and it ended up being pointless (but a good learning experience).

So yeah if you haven't done so already, make changing your spark plug wires a priority.
swl2001 is offline   Reply With Quote
Old 05-16-2015, 05:37 AM   #3
Junior Member
Posts like a V-Tak
 
Join Date: Mar 2015
Posts: 27
Thanked 2 Times in 2 Posts
swl2001 is on a distinguished road
Default

Apparently 8 and ) make a cool person face That was suppose to read code 18*
swl2001 is offline   Reply With Quote
Old 05-17-2015, 11:11 PM   #4
Junior Member
Thread Starter
 
Join Date: Jun 2011
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
hadaford is on a distinguished road
Default

Haha! I'll try the plug wires. Thanks!
hadaford is offline   Reply With Quote
Old 06-06-2015, 03:55 PM   #5
Junior Member
Thread Starter
 
Join Date: Jun 2011
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
hadaford is on a distinguished road
Default

Quote:
Originally Posted by swl2001 View Post
Apparently 8 and ) make a cool person face That was suppose to read code 18*
I replaced the plugs and wires. Really thought I had it when I found #4 wire not actually contacting the plug! Nope! Same problem. Thanks for your suggestion! I really thought that was going to do it.
hadaford is offline   Reply With Quote
Old 06-07-2015, 07:41 PM   #6
Senior Member


Certified GM nut
 
Tech II's Avatar
 
Join Date: Feb 2014
Location: Worcester, Ma.
Posts: 1,661
Thanked 672 Times in 512 Posts
Tech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond repute
Default

Plugs/wires are not going to fix a code 18......we are talking cam sensor, crank sensor, ICM, PCM, cam magnet, interrupter rings on harmonic balancer, wiring, or connectors in the harnesses....which is just about everything you have done....

Were these new or used parts?

When erased, which code comes back first?

Last edited by Tech II; 06-07-2015 at 07:42 PM.
Tech II is offline   Reply With Quote
Old 06-08-2015, 06:00 AM   #7
Junior Member
Thread Starter
 
Join Date: Jun 2011
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
hadaford is on a distinguished road
Default

Tech II,
All parts were new, except the ECM, which was rebuilt. The 18 code is the one that always comes back first.
I borrowed a Snap-On "Brick" this weekend from a guy at work. I'm putting my results in a spreadsheet to see if I can make some sense of it. I DID notice that the O2 Sensor output fluctuated wildly, anywhere from 4 to 840 millivolts. I don't know if that'* normal or not, but it seemed odd. Also one frame showed several other codes that I haven't seen before. They only showed on that one frame. I'll post more when I get it all together.
hadaford is offline   Reply With Quote
Old 09-18-2016, 10:57 PM   #8
Junior Member
Thread Starter
 
Join Date: Jun 2011
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
hadaford is on a distinguished road
Default Still going

Well, it'* been I don't know how long, but still having the same issue. Thanks to those who have made suggestions.

I've come to think, no conclusion, that the part causing the problem has failed completely long ago and that it is brought into play at the time or temp or whatever is triggering the problem. Otherwise, things would have gradually gotten worse to the point of complete failure months ago.

So, any ideas on what component comes into play after 20 minutes or 10 to 12 miles or so?
hadaford is offline   Reply With Quote
Old 09-19-2016, 07:21 AM   #9
Senior Member
True Car Nut
 
rjolly87's Avatar
 
Join Date: Jun 2003
Location: Las Cruces, NM
Posts: 6,611
Thanked 226 Times in 183 Posts
rjolly87 has much to be proud ofrjolly87 has much to be proud ofrjolly87 has much to be proud ofrjolly87 has much to be proud ofrjolly87 has much to be proud ofrjolly87 has much to be proud ofrjolly87 has much to be proud ofrjolly87 has much to be proud ofrjolly87 has much to be proud of
Default

Interesting...

I'll have to remember to pull my 93 c/h body fsm to get more insight on this code. I always did love a good mystery
rjolly87 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
1990 Buick Regal GS 3.1 multi-P running rough help:( Buick455 Buick 4 05-18-2015 10:36 PM
running rough / stalling when warm name GMC/Chevrolet Truck/SUV 5 09-08-2014 09:33 PM
'99 Century 3.1 running rough, codes P0101 & P10171 Peva Buick 19 07-06-2011 11:14 PM
$&)$&*)#&+()#%& )#@(%&#)%*(&+_ Maymybonnieliveforevr Lounge 6 05-02-2007 07:07 PM
mom & hailey, mom & kim, mom & kim & mom harofreak00 Lounge 6 04-09-2007 03:40 PM


Tags
3.8l, 3800, buick regal, regal, stalling

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 On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 01:57 AM.