3.4l DOHC misfire - DTC p1640 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Oldsmobile When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 04-12-2013, 07:41 PM   #1
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2013
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
95lq1vert is on a distinguished road
Default 3.4l DOHC misfire - DTC p1640

HI everyone, New member here. I drive a 1995 Oldsmobile Cutlass Supreme with the vin "x" 3.4L.

I am having a few issues. I'll list them most problematic first.

1. Misfire on #6 cylinder
2. DTC p1640
3. starter is a new reman unit but clicks but doesn't engage everytime.

Any and all help would be appreciated!
95lq1vert is offline   Reply With Quote
Old 04-12-2013, 08:56 PM   #2
Senior Administrator








Certified Car Nut
 
Mike's Avatar
 
Join Date: Jul 2003
Location: Horseheads, NY
Posts: 15,643
Thanked 995 Times in 772 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

1. Misfire....how long since the last tune up?
2. This could be a bad PCM, its a QDM failure. This could take awhile to diagnose.
3. Inspect/Clean battery cables including the smaller starter wire.
Mike is offline   Reply With Quote
Old 04-13-2013, 12:57 AM   #3
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2013
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
95lq1vert is on a distinguished road
Default

Quote:
Originally Posted by Mike1995 View Post
1. Misfire....how long since the last tune up?
2. This could be a bad PCM, its a QDM failure. This could take awhile to diagnose.
3. Inspect/Clean battery cables including the smaller starter wire.
Last tune up was about 1500 miles ago if that, I am running ngk vpower plugs and Ac delco plug wires.

I bought a new canister purge solenoid to see if that was the problem with the qdm failure but to no avail it didnt fix it.

I will check the cables tomorrow weather permitting. lol
95lq1vert is offline   Reply With Quote
Old 04-13-2013, 06:25 PM   #4
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

Try disconnecting the battery cables for 30 minutes, following by touching the two wire ends to each other for a few seconds. That may reset your computer and clear the code.

How do you know cylinder 6 is misfiring unless you are getting additional trouble codes?
2kg4u is offline   Reply With Quote
Old 04-13-2013, 07:52 PM   #5
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2013
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
95lq1vert is on a distinguished road
Default

I have an old actron scanner I bought off of ebay which scans pre OBD 2 cars. Anyways it shows what Cylinder is bad - misfiring in the data stream and it always shows #6.

I can also clear codes with the scan tool, which I did this afternoon because I had the p1640 fault stored in the memory. Otherwise there isn't any other codes present. I'll rescan after I get off work tonight to see if it reappears.
95lq1vert is offline   Reply With Quote
Old 04-13-2013, 07:53 PM   #6
Senior Administrator








Certified Car Nut
 
Mike's Avatar
 
Join Date: Jul 2003
Location: Horseheads, NY
Posts: 15,643
Thanked 995 Times in 772 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

Good deal Doug, keep us posted, and NEVER EVER get rid of that scanner.
Mike is offline   Reply With Quote
Old 04-13-2013, 07:54 PM   #7
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2013
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
95lq1vert is on a distinguished road
Default

EDIT: The misfire is intermittent and usually occurs at idle, but whenever the scan tool is hooked up the only cylinder that shows up for being bad is #6.
95lq1vert is offline   Reply With Quote
Old 04-13-2013, 08:12 PM   #8
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

Disconnecting the battery and touching the cables together is not just to reset the codes, it may reset the computer and correct the problem.

Most misfires are due to a bad plug or plug wire. If you are convinced the plugs and wires are good I would try switching the #6 injector with one of the other positions and see if the misfire follows the injector. Also, try switching coils around and see if the misfire follows the coil from #6. If it is not a bad plug, bad plug wire, bad injector or bad coil, I would do a compression test to see if #6 is low, which would indicate an internal engine mechanical issue.

Even if the plug wires are new, you might want to check the resistance on the #6 wire. It wouldn't be the first time an issue is related to a new part.
2kg4u is offline   Reply With Quote
Old 04-13-2013, 08:13 PM   #9
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

The more I think about it, the more I think its a bad injector.
2kg4u is offline   Reply With Quote
Old 04-13-2013, 08:35 PM   #10
Junior Member
Posts like a Ricer Type-R
Thread Starter
 
Join Date: Apr 2013
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
95lq1vert is on a distinguished road
Default

Quote:
Originally Posted by 2kg4u View Post
Disconnecting the battery and touching the cables together is not just to reset the codes, it may reset the computer and correct the problem.

Most misfires are due to a bad plug or plug wire. If you are convinced the plugs and wires are good I would try switching the #6 injector with one of the other positions and see if the misfire follows the injector. Also, try switching coils around and see if the misfire follows the coil from #6. If it is not a bad plug, bad plug wire, bad injector or bad coil, I would do a compression test to see if #6 is low, which would indicate an internal engine mechanical issue.

Even if the plug wires are new, you might want to check the resistance on the #6 wire. It wouldn't be the first time an issue is related to a new part.
Okay I didnt know that! Thanks.

The other suggestions ill have to try but the injectors and coils are in the most ingorant spots. So it'll be an all day adventure to ge to them.

I also need to get a compression test done. Who knows I might have a few burnt exhaust valves?
95lq1vert is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
3.1L P0300 DTC 'Random/Multiple cylinder misfire' Ben Cartwright General GM Chat 2 08-09-2013 10:27 PM
DTC p0304: misfire, cyl. no. 4, '99 SSEi KiamichiBville 1992-1999 7 01-07-2013 01:33 AM
DTC P0305 - cylinder #5 misfire 2kg4u 2000-2005 27 08-24-2009 09:58 AM
More findings-FIXED!! - 93 SSE: DTC (Code) 42 & DTC 18 93RedSled-SSE 1992-1999 45 04-21-2008 03:21 PM
DTC P0300 Engine Misfire Detected Wargamer 1992-1999 26 05-01-2005 02:57 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 04:36 PM.


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.