Conversions & Swaps LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

5.3 maf trouble

Thread Tools
 
Search this Thread
 
Old Aug 19, 2008 | 08:57 AM
  #1  
garretthes's Avatar
Thread Starter
On The Tree
 
Joined: Nov 2005
Posts: 102
Likes: 0
Default 5.3 maf trouble

My transplant is running but there is one snag. If the MAF sensor is connected it idles rough and won't run very well. Disconnect it and it smooths out and runs OK. We used the factory harness. The guy who programed the ECM suggested I check the wiring on the CAM Position Sensor, Crank Position Sensor and MAF Sensor. I did this and everything is clean. Actually I haven't checked the Crank Position sensor because I have to take the starter off to get to it. He also suggested checking the power and grounds to the 02 and MAF sensors. I'm not sure what voltages to look for there.

I'm stumped. If it's not a bad wire what else could it be? Is anything routed to the instrument cluster then back to the ecm? If so we aren't using the cluster.

Here are the basics on my transplant;
2004 Chevy Silverado 5.3 with 4l60e
Used factory harness but no instrument cluster.
Reply
Old Aug 19, 2008 | 11:38 AM
  #2  
babydeuce's Avatar
TECH Apprentice
20 Year Member
Photogenic
iTrader: (24)
 
Joined: Dec 2005
Posts: 347
Likes: 15
From: Box Elder, SD
Default

Is it throwing any codes? When the MAF is unplugged, it throws the computer into Speed Density mode. Has your tuner adjusted the MAF tables for the particular MAF that you are using?

Jack
Reply
Old Aug 19, 2008 | 01:25 PM
  #3  
garretthes's Avatar
Thread Starter
On The Tree
 
Joined: Nov 2005
Posts: 102
Likes: 0
Default

It wasn't throwing any codes when the MAF was connected. The MAF is the original so I'm assuming it shouldn't need adjusting. What is speed density mode?
Reply
Old Aug 19, 2008 | 05:11 PM
  #4  
Chris10an's Avatar
Launching!
iTrader: (1)
 
Joined: Sep 2007
Posts: 222
Likes: 0
From: Norway
Default

Does the engine produce water in the exhaust, and does it smell gasoline?
Reply
Old Aug 19, 2008 | 06:19 PM
  #5  
garretthes's Avatar
Thread Starter
On The Tree
 
Joined: Nov 2005
Posts: 102
Likes: 0
Default

No unusual smells or water in the exhaust. It runs good as long as you don't give it too much gas. I drove it from Birmingham to Nashville and got 18 mpg. Can't wait to see what it gets when I get the MAF working.
Reply




All times are GMT -5. The time now is 04:58 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE