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

5.3 swap help!

Thread Tools
 
Search this Thread
 
Old Feb 6, 2023 | 05:34 PM
  #1  
jnew07's Avatar
Thread Starter
Registered User
 
Joined: Feb 2023
Posts: 2
Likes: 0
Default 5.3 swap help!

I’m doing a 5.3 swap but can’t get the thing to start.

1999 z28 ls1 PCM
swap harness, has all the grounds converted to 2 grounds (both checked and they are good.)

Has new fuel.
Fuel lines are ran correct.
Has fuel pressure to the rails.
Has spark at the plugs (in correct firing order).
Timing is correct on the cam.
New cam sensor
New crank sensor
New MAF sensor
New map sensor

VATs have been deleted with HP tuners.

I get an initial pop and a flame and after that’s it’s all cranking no more ignition. Keep trying to crank and then I’m just washing out the cylinders I’ll pull the plugs turn it over dry everything out and repeat the process. Showing no codes… x24 reluctor. Got the correct sensors for the x24 reluctor…… just looking for any kinda help? Thanks!
Reply
Old Feb 6, 2023 | 08:28 PM
  #2  
Project GatTagO's Avatar
TECH Senior Member
20 Year Member
Liked
Loved
Top Answer: 1
iTrader: (7)
 
Joined: Mar 2003
Posts: 10,617
Likes: 1,883
From: Little Austin
Default

Originally Posted by jnew07
I’m doing a 5.3 swap but can’t get the thing to start.

1999 z28 ls1 PCM
swap harness, has all the grounds converted to 2 grounds (both checked and they are good.)

Has new fuel.
Fuel lines are ran correct.
Has fuel pressure to the rails.
Has spark at the plugs (in correct firing order).
Timing is correct on the cam.
New cam sensor
New crank sensor
New MAF sensor
New map sensor

VATs have been deleted with HP tuners.

I get an initial pop and a flame and after that’s it’s all cranking no more ignition. Keep trying to crank and then I’m just washing out the cylinders I’ll pull the plugs turn it over dry everything out and repeat the process. Showing no codes… x24 reluctor. Got the correct sensors for the x24 reluctor…… just looking for any kinda help? Thanks!
A pop and a flame tells me that you may have the coil sub harness installed incorrectly...

Andrew
Reply
Old Feb 6, 2023 | 08:38 PM
  #3  
jetech's Avatar
TECH Fanatic
Veteran: Air Force
5 Year Member
Liked
Community Favorite
 
Joined: Jan 2018
Posts: 1,251
Likes: 239
From: Dade City, Fl.
Default

Double check the harness and connections at the crank position sensor. What is the cranking compression?
Reply




All times are GMT -5. The time now is 12:53 PM.

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