[Gmecm] Re: +AFs-Gmecm+AF0- Cold start problem

[David Allen]

  I know this is an old thread but... I am fighting the same cranking issue with my mom's car.  Would you mind telling how much you increased the cold engine cranking pulse widths?
  I was thinking about a 10+ACU- increase on all the table values below operating temperature.  
  Thanks for your advice+ACE- Her car is a 1990 LeSabre with the 3800 engine.  340,000 miles and still going strong+ACEAIQ-
David




----- Original Message ----- 
From: +ACI-Ron Drew+ACI- +ADw-rjdrew+AEA-adelphia.net+AD4-
To: +ADw-gmecm+AEA-diy-efi.org+AD4-
Sent: Saturday, July 08, 2006 6:29 AM
Subject: Re: +AFs-Gmecm+AF0- Cold start problem


+AD4- This may not help, but here is what I have experienced: I have two 3800 
+AD4- engine cars from the same era and I have experienced what you described on 
+AD4- both of them.  In both cases, I measured the secondary ignition voltage and 
+AD4- found that the some of the spark plugs had deteriorated some (the firing 
+AD4- voltage had creeped up from previous taken measurements). After replacing 
+AD4- the plugs, I then tweaked the 'cranking pulse width' (in both cases, I was 
+AD4- slightly lean, so the cranking pulse width had to be slightly increased at 
+AD4- lower coolant temperatures). I don't understand why I had to slightly 
+AD4- increase the cranking pulse width, when each car had previously cranked 
+AD4- fine, however I did this on one car 3 or 4 years ago and it has been fine 
+AD4- since. I applied the same to the second car this year (which I drive during 
+AD4- the week), and both crank now without any issues.
+AD4- 
+AD4- A strong indication that what I experienced is the same reason for your 
+AD4- problem+ADs- is that after trying to crank the engine for a few starter motor 
+AD4- turns, release the key and try to crank the engine a second time. If it is 
+AD4- the slightly lean problem which I described, the car will likely fire right 
+AD4- up on the second try. I think this can be explained because the pulse width 
+AD4- is programmed to progressively decrease the longer you try to run the 
+AD4- starter motor (to prevent flooding the engine) so a second attempt would 
+AD4- provide the extra needed fuel.  I think the only thing that could explain 
+AD4- for the engine firing immediately on the second try is that the programmed 
+AD4- cranking pulse width is slightly too lean.
+AD4- 
+AD4- Ron
+AD4- 
+AD4- 
+AD4- ----- Original Message ----- 
+AD4- From: +ACI-Bill - Comcast+ACI- +ADw-b.shaw+AEA-comcast.net+AD4-
+AD4- To: +ADw-gmecm+AEA-diy-efi.org+AD4-
+AD4- Sent: Friday, July 07, 2006 12:18 AM
+AD4- Subject: +AFs-Gmecm+AF0- Cold start problem
+AD4- 
+AD4- 
+AD4APg- I'm having a cold start problem on my wife's '88 Buick Century wagon and 
+AD4APg- am looking for some advise.  This is a 3.8L v6 with DIS. When trying to 
+AD4APg- start it will crank a second or 2 then fire and then backfire and stall. 
+AD4APg- We have to try 10 to 15 times before it will finally wheeze to life.  Once 
+AD4APg- it starts it runs fine,  no skips or hesitation.  The problem occurs only 
+AD4APg- when it's stone cold, after running for even a minute it will repeatedly 
+AD4APg- start fine.  It's not setting any codes so I'm not getting any help from 
+AD4APg- the ECM.
+AD4APg-
+AD4APg- This started suddenly a couple of days ago.  Before that it fired up 
+AD4APg- quickly warm or cold and ran well.  I thought maybe something weird with 
+AD4APg- the CTS ( remember, no codes) so I changed it (it was cheap and easy 
+AD4APg- anyways) but it made no difference.  Anyone have a thought on what to look 
+AD4APg- at next?
+AD4APg-
+AD4APg- Thanks,
+AD4APg-
+AD4APg- Bill
+AD4APg-
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