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

swap runs! Odd problem now.

Thread Tools
 
Search this Thread
 
Old Apr 15, 2011 | 05:28 AM
  #1  
RATBOX's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Dec 2010
Posts: 685
Likes: 1
From: Lincoln, Nebraska
Default swap runs! Odd problem now.

Well, finally got the LS swap running. I'm using a Speartech harness. 01 LS1 and harness.

For some reason the engine is only firing on cylinders 1, 7, 6, 4. But not a thing on 2, 3, 5, 8. It's like it's skipping every other cylinder in the firing order?? I'm baffled. Hoping it's something simple, but I can't seem to think for a second what'd cause that.

Ideas?
Reply
Old Apr 15, 2011 | 10:04 AM
  #2  
mille_3's Avatar
On The Tree
iTrader: (1)
 
Joined: Sep 2007
Posts: 118
Likes: 1
From: ND
Default

Is it throwing any codes? Are you getting power to your injector connectors?
Reply
Old Apr 15, 2011 | 11:28 AM
  #3  
Pocket's Avatar
TECH Addict
15 Year Member
iTrader: (22)
 
Joined: Apr 2009
Posts: 2,656
Likes: 149
From: NC
Default

Call speartech
Reply
Old Apr 15, 2011 | 01:05 PM
  #4  
RATBOX's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Dec 2010
Posts: 685
Likes: 1
From: Lincoln, Nebraska
Default

Originally Posted by mille_3
Is it throwing any codes? Are you getting power to your injector connectors?
I'd think so, it's got power to fire 2 cylinders per side?
Reply
Old Apr 15, 2011 | 02:54 PM
  #5  
72chevelle6.0's Avatar
Launching!
iTrader: (22)
 
Joined: Nov 2005
Posts: 236
Likes: 0
From: TX 76511
Default

are you sure your coil harness is plugged in the correct order? a friend had his backwards and it was driving him nuts
Reply
Old Apr 16, 2011 | 12:12 AM
  #6  
RATBOX's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Dec 2010
Posts: 685
Likes: 1
From: Lincoln, Nebraska
Default

The way the harness is, everything will only plug into where it should. In order to plug something in wrong, you'd have to have the harness literally on backwards. What are the odds of this being caused by a cam or crank sensor only being plugged in partly? They're a real nightmare to get to with as close as the motor is to the firewall. Fairly certain they got plugged in all the way, but they're the only ones I can't readily see with my eyes.

I talked with speartech today and he assured me the harness was working correctly on his setup before it got shipped out, which I'd have to believe. So, I'm hoping it's something simple. Posted this to see if anyone else had encountered anything similar so I'd have a starting point in where to start looking.
Reply
Old Apr 16, 2011 | 08:22 AM
  #7  
mille_3's Avatar
On The Tree
iTrader: (1)
 
Joined: Sep 2007
Posts: 118
Likes: 1
From: ND
Default

I would start by making sure everything is actually plugged in, check for pinched wires, make sure your main plugs at the PCM are plugged in all the way and torqued down properly. Verify that you actually have 12V+ at your individual injector plugs.
Reply
Old Apr 16, 2011 | 12:39 PM
  #8  
RATBOX's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Dec 2010
Posts: 685
Likes: 1
From: Lincoln, Nebraska
Default

Ya, were headed out to the shop tonight after I get off of work. I'm going to go through and double check all the connections. Unfortunately I can't start it that late at night behind the psychotic welfare lady who lives on the same lot that my shop is on, is off her meds and already verbally assaulted me the other morning after it started for 10 seconds. I almost felt like threatening her with not paying my taxes anymore so then she'd have to find someone else to pay for her 5 illegitimate children.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Apr 22, 2011 | 02:52 AM
  #9  
RATBOX's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Dec 2010
Posts: 685
Likes: 1
From: Lincoln, Nebraska
Default

Well, figured it out. The PCM must have some bad drivers in it. Checked continuity in the Speartech harness and all was well, but no spark on 4 cylinders. Grabbed a pcm from a 01 WS6, uploaded my tune to it and it fired up today hitting on all 8 no problem.

ODD, considering the pcm and LS1 was working awesome before we yanked it for my car. I send the pcm and harness to Speartech, PCM is junk after hooking it up in my car after we get it back. Not impressed, but whatever. I'm just glad to have it all sorted it out and ready for driving and terrorizing the big block's again.
Reply
Old Apr 22, 2011 | 04:06 AM
  #10  
itsslow98's Avatar
TECH Senior Member
iTrader: (18)
 
Joined: Apr 2006
Posts: 6,762
Likes: 5
From: Maryland
Default

Congrats man, im waiting on my PSI harness at the moment and then its just odds and ends and Ill be firing it up. Once again congrats and post how she runs!
Reply
Old Apr 22, 2011 | 01:37 PM
  #11  
RATBOX's Avatar
Thread Starter
TECH Enthusiast
iTrader: (26)
 
Joined: Dec 2010
Posts: 685
Likes: 1
From: Lincoln, Nebraska
Default

Thanks man. Going to bolt the front clip back on middle of next week and put insurance back on it and take it for a spin.
Reply




All times are GMT -5. The time now is 10:40 AM.

story-0
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-1
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-2
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-3
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-4
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-5
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
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE