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

LS foxbody help with issue?

Thread Tools
 
Search this Thread
 
Old Sep 25, 2014 | 09:45 AM
  #1  
cordova87's Avatar
Thread Starter
On The Tree
iTrader: (5)
 
Joined: Jun 2010
Posts: 146
Likes: 0
Default LS foxbody help with issue?

Hey fellas so I completed my LS swap on my Foxbody. But i'm having some sort of issue with the car. Havent had time till now. Car starts up fine and drives but at WOT I LOOSE POWER like something is holding it back RPM's go up fine but car just wont grab or pull like it should feel's like it wants to. Any ideas what could be the issue would be helpful. I dont want assume but here's a couple thing I have in mind.

1. Not enought fuel...i still have the stock 4cyl fuel pump with a corvetter FPR
2. maybe i need a tune, PCM was flash a deleted the vats
3. Trans could have a issue, fluid looks good, but ill check it again
4. torque management

Keep in mind that cars drives fine and shift fine had a guy check it with hptuners and said gears went in all fine.

What can be the issue?
Reply
Old Sep 25, 2014 | 01:33 PM
  #2  
cordova87's Avatar
Thread Starter
On The Tree
iTrader: (5)
 
Joined: Jun 2010
Posts: 146
Likes: 0
Default

tttt...

Last edited by cordova87; Sep 25, 2014 at 02:11 PM.
Reply
Old Sep 25, 2014 | 02:56 PM
  #3  
lsxRanger94's Avatar
12 Second Club
 
Joined: Jan 2014
Posts: 565
Likes: 0
From: 217
Default

If the car lays over on the upper end of the rpm range, It is usually fuel related. A factory fuel pump is rated at 56psi and 23gph/88lph(new). your ls should have 58psi. You could tune it to run with this, but you won't have the performance you should out of the engine. The correct thing to do is upgrade fuel pump. Even though the 5.0 had the same pump, it was barely enough to support its 225 hp.
Reply
Old Sep 25, 2014 | 02:59 PM
  #4  
dlove's Avatar
TECH Fanatic
iTrader: (23)
 
Joined: Sep 2005
Posts: 1,449
Likes: 1
From: Fort Worth
Default

A wideband would be very helpful. I'm going to guess fuel though.
Reply
Old Sep 25, 2014 | 03:18 PM
  #5  
cordova87's Avatar
Thread Starter
On The Tree
iTrader: (5)
 
Joined: Jun 2010
Posts: 146
Likes: 0
Default

Originally Posted by lsxRanger94
If the car lays over on the upper end of the rpm range, It is usually fuel related. A factory fuel pump is rated at 56psi and 23gph/88lph(new). your ls should have 58psi. You could tune it to run with this, but you won't have the performance you should out of the engine. The correct thing to do is upgrade fuel pump. Even though the 5.0 had the same pump, it was barely enough to support its 225 hp.
thxs, yes my psi is at 58. tonigh ill record my fuel pressure gauge if its constantly at 58 or above... hoping this could determent if the fuel is the issue.
Reply




All times are GMT -5. The time now is 01:08 PM.

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