5.3l swap problems

Reply Subscribe

Thread Tools

Search this Thread

May 8, 2011 | 12:51 AM

Jayhill

Thread Starter

Teching In

Joined: Sep 2010

Posts: 14

Likes: 0

From: Cleveland, ms

5.3l swap problems

Put a 05 5.3l lm7 in a 84 2door caprice. Bought a harness and computer from PSI. Computer was programed. After completing everything engine just turns but will not crank. Got gas pumping to fuel rails. Got a noid light an checked injector plugs for signal from harness. Pulled plugs one by one and checked for spark. Any info is greatly appreciated

May 8, 2011 | 01:33 AM

Jayhill

Thread Starter

Teching In

Joined: Sep 2010

Posts: 14

Likes: 0

From: Cleveland, ms

Checked old plugs changed out an tried to start it. Still no start bought new plugs an tried again. Pulled plugs an noticed gas on them.

May 8, 2011 | 02:46 AM

Gee101

Staging Lane

iTrader: (8)

Joined: Oct 2006

Posts: 71

Likes: 0

From: Regina, SK

Check with who ever programmed the pcm to make sure they disabled vats. If you know forsure they disabled vats then put a scanner on it and check for codes.

May 8, 2011 | 08:58 AM

Old Geezer

TECH Senior Member

iTrader: (3)

Joined: Jun 2004

Posts: 5,639

Likes: 71

From: GA, USA

How long has the engine been sitting?? A chance that the injs are stuck is good, if it's a junk yard engine that's had gas in the rails for an extended time...

May 8, 2011 | 10:19 AM

the_merv

Banned

iTrader: (88)

Joined: Mar 2006

Posts: 21,019

Likes: 893

From: The Beach...

VATS disables the Injectors, not the spark.

Check Rail Pressure when the pump is priming, check all grounds for the Coil Packs.

May 8, 2011 | 10:29 AM

the_merv

Banned

iTrader: (88)

Joined: Mar 2006

Posts: 21,019

Likes: 893

From: The Beach...

Post some pics up if you can..I have a friend with a 87 2-door Caprice I'm tryin to get to convert to LS..

May 8, 2011 | 10:51 AM

deuce4935

TECH Resident

iTrader: (2)

Joined: Sep 2006

Posts: 760

Likes: 3

Are you sure the pcm is getting a constant 12 volts during the cranking cycle? Double check all grounds, (engine to frame, frame to body, battery to frame). Good to see another box body Caprice being converted to LSx power. I've been driving my 80' Caprice Landau(98' LS1/4l60e, z06 topend) for 3 years now and man its a blast everytime I get behind the wheel. Pm me if you need some pointers.