Tuning, Diagnostics, Electronics, and Wiring HP Tuners | EFILive | Hand Held Programmers | Stand Alone PCM's | Electronics | Wiring Diagrams

Who has problems with hot starts?

Thread Tools
 
Search this Thread
 
Old Jun 23, 2012 | 04:05 PM
  #11  
LsF-150's Avatar
Launching!
iTrader: (2)
 
Joined: Feb 2010
Posts: 237
Likes: 0
Default

any codes? a failed cam position sensor will cause extended crank
Reply
Old Jun 24, 2012 | 04:45 PM
  #12  
oakley6575's Avatar
Thread Starter
TECH Senior Member
15 Year Member
iTrader: (5)
 
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
Default

No codes. Cam sensor is good. Looks like I might have a handle on it now. I doubled the first pulse mass table under cranking fuel and it seemed to help. So I tripled it and it got even better. I guess it needs a pretty healthy pulse to fire when its hot. I don't know if that is due to the bigger cubes or different injectors or...? But it looks like I found the problem. Thanks everyone
Reply
Old Jun 24, 2012 | 05:49 PM
  #13  
AndysC3's Avatar
TECH Addict
iTrader: (14)
 
Joined: Jun 2009
Posts: 2,884
Likes: 10
From: Minot, ND
Default

I was have issues with hot starts. I use EFI Live. I added air to the startup airflow correction and it has worked very well so far.
Reply
Old Jun 25, 2012 | 01:25 AM
  #14  
oakley6575's Avatar
Thread Starter
TECH Senior Member
15 Year Member
iTrader: (5)
 
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
Default

Mine hates idle airflow. I have to zero the airflow out above 120 degrees
Reply
Old Jun 27, 2012 | 05:43 PM
  #15  
oakley6575's Avatar
Thread Starter
TECH Senior Member
15 Year Member
iTrader: (5)
 
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
Default

I give up. I change stuff and think it gets better but it just isn't consistant. Ive tried every cranking table I can find except using the second pulse mass... Any insight on this table?
Reply
Old Jun 27, 2012 | 06:18 PM
  #16  
2007chevy5.3l's Avatar
TECH Addict
iTrader: (21)
 
Joined: Apr 2008
Posts: 2,625
Likes: 0
From: Fort Worth, Texas
Default

Cant look at your log since I use EFIlive but whats the IATs and the AFRs when this happens?
Reply
Old Jun 27, 2012 | 06:39 PM
  #17  
oakley6575's Avatar
Thread Starter
TECH Senior Member
15 Year Member
iTrader: (5)
 
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
Default

My iat reading is from the factory location in the MAF. In vegas, once the truck is turned off, the ect climbes for another 10-20 min. The underhood temp is crazy high it never wants to start in this case. The IAT can easily get up to 140 from what I've seen. What effect does the IAT have on cranking tables?
Reply
Old Jun 27, 2012 | 06:41 PM
  #18  
oakley6575's Avatar
Thread Starter
TECH Senior Member
15 Year Member
iTrader: (5)
 
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
Default

Also, I don't understand what people mean when they talk about cranking AFR. You don't get an afr reading until the truck has started. So I guess if your asking about the afr on initial fire up, then its right around stoich.
Reply
Old Jul 26, 2012 | 02:31 AM
  #19  
oakley6575's Avatar
Thread Starter
TECH Senior Member
15 Year Member
iTrader: (5)
 
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
Default

Bringing this back up. Does anyone know exactly what the FA mult stage 1 table does under the cranking fuel section? I'm having a hard time understanding how that table effects fuel. Thanks






Originally Posted by KLUG'S SS
As suggested already I would definitely check anything fuel related not in the tune first. Fuel pump, regulator, fuel filter? Make sure you've got good pressure at all times at the rail.?
I went throught the fuel system this weekend. I added a aeromotive fpr with a vacuum reference. Fuel pressure was set to 58psi with the vacuum port open to the atmosphere. It idles right at 46psi with the port hooked up to the back of the manifold. I also changed the fuel filter and the pump is still strong.
Reply
Old Jul 26, 2012 | 06:49 PM
  #20  
LsF-150's Avatar
Launching!
iTrader: (2)
 
Joined: Feb 2010
Posts: 237
Likes: 0
Default

If your not running beta, can you post a tune? Have you done anything with the Startup and Friction Airflow tables?
Reply



All times are GMT -5. The time now is 05:54 AM.