H2 supercharged hard start - Hummer Forums - Enthusiast Forum for Hummer Owners


Hummer H2 For those who like a little more gleam to their Hummer, the H2 offers a similar rugged look as the H1, but as a lower cost, and with more added features, making it almost a massive luxury SUV.

Reply
 
 
 
Thread Tools Search this Thread
  #1  
Old 05-15-2018, 04:56 PM
Senior Member
Thread Starter
 
Join Date: Jun 2009
Posts: 180
Default H2 supercharged hard start

Hi, I have a hummer h2 supercharged I just got, that when I try to start it with the engine cold, it cranks a little before it actually starts.
If I try to crank it after the engine is hotter, it cranks as it should.

Battery is fine.
I have checked fuel pressure and it's ok.
I switched the MAF with another H2 and the problem remains.
There are no errors showing up (no engine light on).


When I start it cold, it cranks a little and it starts with low RPMS (on other good working H2s, usually the RPMS peak a little then it idles) on this H2 when it starts it doesn't give that little peak.

Any suggestions on what it could be?
Reply With Quote
  #2  
Old 05-16-2018, 06:44 AM
Senior Member
 
Join Date: Mar 2014
Location: Viera, FL
Posts: 222
Default

You likely have a fault in the IAC or TPS.

You would have to get into the settings on the ECM and check the settings and or check for faults.

It MIGHT be entirely possible to reset each by disconnecting the battery for a few mins and then doing a throtttle re-learn.

Tim
Reply With Quote
  #3  
Old 05-16-2018, 10:05 AM
Senior Member
Thread Starter
 
Join Date: Jun 2009
Posts: 180
Default

How can i do a throttle relearn?
Reply With Quote
  #4  
Old 05-16-2018, 01:03 PM
MixManSC's Avatar
Senior Member
 
Join Date: Jan 2017
Location: SC
Posts: 554
Default

With a Tech2.... I think some of the expensive higher end scan tools that mechanics have from Snap On / Mac Tools, etc also have the programming to do a throttle relearn. I'm not sure there is any other way.
Reply With Quote
  #5  
Old 05-16-2018, 01:55 PM
Senior Member
Thread Starter
 
Join Date: Jun 2009
Posts: 180
Default

I talked to the shop that is trying to fix this problem, and they said they already tried switching the throttle body from another h2 I left there, to the one that has the problem and it behaved the same, it didn't fix anything.

That should eliminate the possibility of it being a IAC or TPS problem, right?
Reply With Quote
  #6  
Old 05-16-2018, 02:58 PM
Senior Member
 
Join Date: Mar 2014
Location: Viera, FL
Posts: 222
Default

Quote:
Originally Posted by Cashville View Post
I talked to the shop that is trying to fix this problem, and they said they already tried switching the throttle body from another h2 I left there, to the one that has the problem and it behaved the same, it didn't fix anything.

That should eliminate the possibility of it being a IAC or TPS problem, right?
NO because the ecm doesn't know that the part has been changed.

Check google for the relearn procedures or atleast disconnect battery for a few mins and see it it will adjust itself.

Tim
Reply With Quote
  #7  
Old 05-16-2018, 04:49 PM
Senior Member
Thread Starter
 
Join Date: Jun 2009
Posts: 180
Default

I searched the relearn procedure and found it (turn engine on in park for 3min, turn off for 60seconds, turn engine on for 3min in park again), i will try it tomorrow to see if it changes anything.
Reply With Quote
  #8  
Old 05-21-2018, 01:21 PM
Senior Member
Thread Starter
 
Join Date: Jun 2009
Posts: 180
Default

I did the throttle relearn process but nothing changed.
Here is a video I made today of a cold engine start, maybe someone can identify something from the video.

Reply With Quote
  #9  
Old 05-22-2018, 08:58 AM
Senior Member
 
Join Date: Mar 2014
Location: Viera, FL
Posts: 222
Default

You need to take it to a tuner and see where the temperature based idle rpm is at. Its hard to trouble shoot without having it on a computer to see where everything is at. You might go over the LS1.com board and read some tuning info and or pose the same question over there. I'm far from a tuning expert but know enough to get by.

Tim
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
2000 H1 Hard to start in mornings Rdourro1 Hummer H1 2 11-01-2017 02:04 PM
H1 Starts & Shuts Off Plus Hard Start rob333 Hummer H1 7 01-20-2017 10:29 AM
95 5.7l tbi hard start/ no start when hot marsstar102 Hummer H1 2 02-29-2012 06:14 PM
Why is installing alarm/remote start so hard 281hummer Hummer H3 3 06-14-2010 09:49 AM
95 H1 Diesel Stalls, Smokes, Hard to Start J95H1 Hummer H1 3 10-29-2008 11:55 AM


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


Advertising
Featured Sponsors

All times are GMT -5. The time now is 06:24 AM.


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.