HELP! Issues after LS6 intake install

Reply Subscribe

Thread Tools

Search this Thread

Oct 2, 2010 | 07:55 PM

WSsick

Thread Starter

12 Second Club

iTrader: (13)

Joined: Apr 2008

Posts: 2,417

Likes: 3

From: St. Peters, MO

HELP! Issues after LS6 intake install

Just got done with the ls6 manifold install. Started the car up, sounds fine but the tach is dead. It moves off the resting pin but doesnt work after that. I took the car up to a good amount of RPMs, and it runs fine. Shut the car off, start it again and it works Shut it off, try it again but this time it backfires big time out the exhaust after not starting. Try again, starts fine. Try again,, won't start, small backfire. We repeat this process with it starting and not starting for a while, with the only lead being that when we play with the clip going to the fuel pressure regulator, it starts every time. Other than that its hit and miss, but car drives fine once started.

Can anyone help with these issues?
-Dead tach
-Starting inconsistently

Oct 2, 2010 | 11:19 PM

ShevrolayZ28

TECH Addict

iTrader: (4)

Joined: May 2005

Posts: 2,318

Likes: 1

From: Massachusetts

Any SES lights? Codes?

Oct 3, 2010 | 12:46 PM

WSsick

Thread Starter

12 Second Club

iTrader: (13)

Joined: Apr 2008

Posts: 2,417

Likes: 3

From: St. Peters, MO

Quote:

Originally Posted by ShevrolayZ28

Any SES lights? Codes?

That's the thing, I am throwing some for the rear o2 delete and I think the EGR, both from when I did the headers so those are nothing new. I need to run over to a friends house to get them check this morning after work.

Here is what a friend told me, and it makes sense to me to be the crank position sensor:

Quote:

I don't remember if it is the crank or cam think it's the crank that feeds your rpm gauge. The PCM cannot tell engine position without the crank sensor but it does know when the piston is at TDC (via the cam position sensor) just not if that is the power stroke or if it's the end of the exhaust stroke, so the pcm will try different combos till the engine fires off then it just runs off the cam sensor, going in firing order in degrees because it knows that in the memory of the pcm. The times it starts is the pcm getting lucky lol Should be a code for a crank sensor if thats the issue

Oct 3, 2010 | 01:21 PM

bene

Trunion King

iTrader: (16)

Joined: May 2006

Posts: 4,394

Likes: 3

From: Texan in Colorado

I think you either accidentally unplugged the cam sensor at the back or you forgot to plug it back in. The crank sensor is right next to the oil pressure sensor.

EDIT: cam sensor... not crank.

Last edited by bene; Oct 3, 2010 at 05:15 PM.

Oct 3, 2010 | 01:57 PM

WSsick

Thread Starter

12 Second Club

iTrader: (13)

Joined: Apr 2008

Posts: 2,417

Likes: 3

From: St. Peters, MO

Quote:

Originally Posted by bene

I think you either accidentally unplugged the crank sensor at the back or you forgot to plug it back in. The crank sensor is right next to the oil pressure sensor.

...which we broke when pulling the LS1 out. So yes, you could be right. (We think the OPSU was broke beforehand since it was cracked at the base and we pulled it out SUPER slow and it never really broke off completely. Also, the new one reads a lot higher than the old one.)