Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Pontiac > Trans Sport
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools
Old 06-22-2018, 02:16 PM   #1
Meridivs
AF Regular
 
Meridivs's Avatar
 
Join Date: Aug 2007
Location: Bucharest
Posts: 202
Thanks: 28
Thanked 0 Times in 0 Posts
Near End of Life. Please Help!

Our trusty Pontiac TS 3.1L SE has developed a bad case of misses while hot. It's like the engine cuts-out for a second then recovers and so on until it eventually stops. In higher revs it's usually ok but sometimes the rpm just drops.


Nothing we've tried so far had any effect:
- changed the whole distributor assembly with ignition-control chip and new pick-up coil
- changed the ignition coil
- tried another engine computer/ECU
- spark plugs are original ACDelcos and new
- spark plug wires are new
- Idle Air Control valve is new
- every other sensor checked-out ok


We're at the ropes-end with this one.


Any ideas on what we could try before throwing in the towel?
Meridivs is offline   Reply With Quote
Old 06-23-2018, 11:05 PM   #2
Tech II
AF Fanatic
 
Join Date: Jul 2011
Location: Worcester, Massachusetts
Posts: 5,017
Thanks: 70
Thanked 618 Times in 610 Posts
Re: Near End of Life. Please Help!

Year?

Check for any codes set?

TBI, multi port, or sequential injection?

Have you done a coil output test at the end of each ignition wire?

How many miles?

Done a compression check?
Tech II is offline   Reply With Quote
Old 06-26-2018, 10:32 AM   #3
Meridivs
AF Regular
Thread starter
 
Meridivs's Avatar
 
Join Date: Aug 2007
Location: Bucharest
Posts: 202
Thanks: 28
Thanked 0 Times in 0 Posts
Re: Near End of Life. Please Help!

1992 3.1L V6 TBI with 160K miles.

No codes on the diagnose interface (I have the ALDL software on a laptop but nothing's out of the ordinary).

Just changed the EGR valve with a new Delphi unit, no effect - engine maintains idle until gets hot then just starts to misfire at idle until it dies.

Here is a sample audio file with engine running:

http://pc.cd/v3dctalK

I remember a post from LMP saying something about an Ignition Relay, does anybody knows where that might be located?

Any other ideas?
Meridivs is offline   Reply With Quote
Old 06-26-2018, 04:28 PM   #4
LMP
AF Enthusiast
 
LMP's Avatar
 
Join Date: Jun 2004
Location: Chicoutimi Quebec
Posts: 3,284
Thanks: 7
Thanked 76 Times in 75 Posts
Re: Near End of Life. Please Help!

My 1993 3.8 has an ignition module. ONce dead, that was it: not intermittent. Totally different from your 3.1 that uses a rotating distributor.
The other issue was the ignition switch itself. Started as an intermittent problem..but got worse with time. It is acted on via a long metal link that goes to the ignition key barrel. It is located low on the steering colums and almost out of reach. I have simply added a relay that I turn ON with a separate toggle switch . This relay applies 12V to the fuel pump circuit (common to the ignition circuit). I still need the key to start but the engine, once started, is kept alive by this circuit. But again this is for the 3.8.
__________________
'93 Ponty Transport 3.8; 2011 SUzuki SX4 AWD (wife's) ; 2015 Sorento 2.4 AWD 1928 Graham Paige Model 629
I don't believe in miracles.
LMP is offline   Reply With Quote
The Following User Says Thank You to LMP For This Useful Post:
Meridivs (06-27-2018)
Old 06-27-2018, 06:45 AM   #5
Meridivs
AF Regular
Thread starter
 
Meridivs's Avatar
 
Join Date: Aug 2007
Location: Bucharest
Posts: 202
Thanks: 28
Thanked 0 Times in 0 Posts
Thumbs up Re: Near End of Life. Please Help!

Thank you for the pointer - I've seen in the catalog two parts:
- an ignition relay
- an ignition switch

LMP, you said about the ignition switch failing and causing intermittent operation/misfires?

I'm guessing that these parts are common between the 3.1 and 3.8L Pontiac TS.

Do you have an idea where the ignition relay might be located on the TS? I might check/change that also while we're at it.
Attached Images
File Type: jpg Ignition Relay.jpg (81.1 KB, 0 views)
File Type: jpg Ignition Switch.jpg (62.4 KB, 1 views)
Meridivs is offline   Reply With Quote
Old 06-27-2018, 07:13 AM   #6
maxwedge
A990 racer
 
Join Date: Mar 2002
Location: Chestertown, New York
Posts: 16,946
Thanks: 25
Thanked 369 Times in 363 Posts
Re: Near End of Life. Please Help!

I would suggest checking fuel pressure also.
__________________
maxwedge is offline   Reply With Quote
Old 06-27-2018, 10:55 AM   #7
Meridivs
AF Regular
Thread starter
 
Meridivs's Avatar
 
Join Date: Aug 2007
Location: Bucharest
Posts: 202
Thanks: 28
Thanked 0 Times in 0 Posts
Re: Near End of Life. Please Help!

The fuel pressure is all right - just changed the fuel pump a few months ago - before that it took 2 keys to get it started, now it starts right away with the new fuel pump.

On a second note this car also has an alternative LPG fuel system that's independent from the original ones, when it misfires it misfires on either fuel system which lead us to think it's an ignition issue.
Meridivs is offline   Reply With Quote
Old 10-11-2018, 02:47 AM   #8
Jeffrv
AF Regular
 
Jeffrv's Avatar
 
Join Date: Jun 2006
Location: North Bay
Posts: 248
Thanks: 0
Thanked 36 Times in 35 Posts
Re: Near End of Life. Please Help!

Another thing to look for is a poor ground for the computer. I believe it is located on a ground stud just above the starter; check the wiring for looseness and corrosion.
Jeff
Jeffrv is offline   Reply With Quote
The Following User Says Thank You to Jeffrv For This Useful Post:
Meridivs (10-15-2018)
 
Reply

POST REPLY TO THIS THREAD

Go Back   Automotive Forums .com Car Chat > Pontiac > Trans Sport

Thread Tools

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



All times are GMT -5. The time now is 03:03 AM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts