GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

5.3L Tahoe hard to crank

Thread Tools
 
Search this Thread
 
Old Dec 2, 2013 | 08:01 PM
  #21  
99corvette's Avatar
Thread Starter
10 Second Club
iTrader: (12)
 
Joined: Oct 2006
Posts: 1,023
Likes: 0
From: Alabama
Default

Originally Posted by okieraptor
Where is the IAT sensor at on theses?
They are built into the MAF
Reply
Old Dec 2, 2013 | 08:12 PM
  #22  
okieraptor's Avatar
Staging Lane
 
Joined: Mar 2012
Posts: 67
Likes: 0
From: southern Oklahoma
Default

Ah ok. My reads right when warm but I've never checked it when it was cold.
Reply
Old Dec 2, 2013 | 10:54 PM
  #23  
1FastBrick's Avatar
Custm2500's Rude Friend
15 Year Member
Loved
Liked
Community Favorite
iTrader: (17)
 
Joined: Apr 2007
Posts: 14,597
Likes: 902
From: JunkYard
Default

Does this have a fuel pressure regulator on the driver side fuel rail???
Reply
Old Dec 3, 2013 | 04:00 AM
  #24  
99corvette's Avatar
Thread Starter
10 Second Club
iTrader: (12)
 
Joined: Oct 2006
Posts: 1,023
Likes: 0
From: Alabama
Default

Originally Posted by 1FastBrick
Does this have a fuel pressure regulator on the driver side fuel rail???
Yeah, I pulled the vacuum line off and let it run for about 5 mins and no fuel ever came out.
Reply
Old Dec 3, 2013 | 09:31 AM
  #25  
99corvette's Avatar
Thread Starter
10 Second Club
iTrader: (12)
 
Joined: Oct 2006
Posts: 1,023
Likes: 0
From: Alabama
Default

I unplugged the coolant temp sensor and treys to crank it when cold and it had no effect.
Reply
Old Dec 3, 2013 | 03:07 PM
  #26  
Suburbazine's Avatar
TECH Fanatic
 
Joined: Feb 2009
Posts: 1,635
Likes: 1
From: Baton Rouge, LA
Default

Originally Posted by 99corvette
I unplugged the coolant temp sensor and treys to crank it when cold and it had no effect.
Unplugged will cause the fueling tables to go bonkers on a cold start.
Reply
Old Dec 3, 2013 | 03:13 PM
  #27  
1FastBrick's Avatar
Custm2500's Rude Friend
15 Year Member
Loved
Liked
Community Favorite
iTrader: (17)
 
Joined: Apr 2007
Posts: 14,597
Likes: 902
From: JunkYard
Default

Need to put a fuel gage on the rail and test it. Pull the vacuum line and it should jump up 8-10 psi.

If it does not, it might not be working correctly.

Have you cleaned the throttle body and idle air control valve?
Reply
Old Dec 3, 2013 | 03:44 PM
  #28  
99corvette's Avatar
Thread Starter
10 Second Club
iTrader: (12)
 
Joined: Oct 2006
Posts: 1,023
Likes: 0
From: Alabama
Default

Originally Posted by Suburbazine
Unplugged will cause the fueling tables to go bonkers on a cold start.
It wouldn't even crank just like with it plugged up.
Reply
Old Dec 3, 2013 | 03:47 PM
  #29  
99corvette's Avatar
Thread Starter
10 Second Club
iTrader: (12)
 
Joined: Oct 2006
Posts: 1,023
Likes: 0
From: Alabama
Default

Originally Posted by 1FastBrick
Need to put a fuel gage on the rail and test it. Pull the vacuum line and it should jump up 8-10 psi.

If it does not, it might not be working correctly.

Have you cleaned the throttle body and idle air control valve?
Test it how? I already put a gauge on it and it read 48psi with just key on and pump primed not cranked and goes to 50psi running.

I did clean the TB but where is the IACV?
Reply
Old Dec 3, 2013 | 07:28 PM
  #30  
Suburbazine's Avatar
TECH Fanatic
 
Joined: Feb 2009
Posts: 1,635
Likes: 1
From: Baton Rouge, LA
Default

Originally Posted by 99corvette
Test it how? I already put a gauge on it and it read 48psi with just key on and pump primed not cranked and goes to 50psi running.

I did clean the TB but where is the IACV?
Engine running, gauge hooked up, pull the vacuum hose off the regulator. You should see a pressure spike.

If you have a DBW throttle body, you have no IACV. If you have a DBC, it's the small gold round thing on the upper right side. The holes in front of the blade are where the IACV draws from.
Reply



All times are GMT -5. The time now is 10:38 AM.