Rich and Lean

N

nic01scgt

Member

Jul 6, 2005

48

0

6

Saint Louis

Jul 14, 2005

#1

• Jul 14, 2005

• #1

Well I took my car up to 1st Capital 4WD today to get dyno tuned and got some bad news. While on the dyno the car would go from rich to lean then rich then back to lean. He also said he found some gas in the crankcase. Could this be from a bad injector leaking or what. Do you guys have any ideas?

 

Lons2001GT

New Member

Nov 16, 2003

75

0

0

Jul 14, 2005

#2

• Jul 14, 2005

• #2

Too many possiblilities without looking the car over in person and looking at the data log info from the dyno session.

 

flashstang04

New Member

Jun 7, 2004

154

0

0

Wichita Falls,Tx

Jul 14, 2005

#3

• Jul 14, 2005

• #3

I though this thread was about a rich skinny chick...oh well,
really, the guy doing the dyno should have been able to tell you something by the data log.

 

csledd

Official Ovary Punching Member

Founding Member

Aug 18, 2001

1,115

1

0

Paducah, KY

Jul 15, 2005

#4

• Jul 15, 2005

• #4

you got a s/c on there? has that been tuned? what kinda numbers did you put down?

 

Mike97gt

it doe snot

Founding Member

Jan 26, 1999

10,633

7

89

the people's republic of massachusetts

Jul 15, 2005

#5

• Jul 15, 2005

• #5

they could'nt figure it out on the dyno? then we have no chance of figuring it out here.

 

N

nic01scgt

Member

Jul 6, 2005

48

0

6

Saint Louis

Jul 15, 2005

#6

• Jul 15, 2005

• #6

I just thought I'd ask you guys to see if anyone else had the same problem. I left the car there over night so hopefully tomorrow he'll have some answers for me. He said he thought it might be a bad injector because there was gas in the crankcase so we'll see. And yes there's a supercharger on there but I don't knwo the numbers

 

N

nic01scgt

Member

Jul 6, 2005

48

0

6

Saint Louis

Jul 15, 2005

#7

• Jul 15, 2005

• #7

Well if anyone was wondering what was wrong it was my fuel pressure regulator and my throttle position sensor. I still don't know how that translates to gas in the crankcase? Also what is the normal output for the FPR? He said mine was fluctuating for 10-12 lbs. Could this explain the rich to lean? Also he said my TPS was giving out 1.2-1.3 volts and he said that was bad and I needed a new one of those. Anyone have any comments?

 

Superhereaux

chicks make me feel inadequate

Founding Member

Jul 30, 2002

538

3

59

South Texas

Jul 15, 2005

#8

• Jul 15, 2005

• #8

not too sure on the fuel pressure, don't know stock specs

as for the tps, voltage should vary from around .8 (tb closed) to around 4.5 (wot)


if you have a voltmeter you can check for yourself

 

hotmustang331

Active Member

Apr 29, 2004

2,967

3

48

Bastrop,TX

Jul 15, 2005

#9

• Jul 15, 2005

• #9

Gas in the crank case? How the heck did he come to that conclusing? Did he check your oil, or drain your oil? You need a tune....but it could be the TPS thing that messing you up.

 

Mike97gt

it doe snot

Founding Member

Jan 26, 1999

10,633

7

89

the people's republic of massachusetts

Jul 15, 2005

#10

• Jul 15, 2005

• #10

fuel in the crankcase.. are you sure this thing is firing on all cyl. a random misfire can cause the a/f too jump all over the place due too the unburned oxegen from a misfire. the sensor does not pick up the fuel only oxegen so it sees this as a lean condition..

 

N

nic01scgt

Member

Jul 6, 2005

48

0

6

Saint Louis

Jul 16, 2005

#11

• Jul 16, 2005

• #11

Well I'm guessing since it's been running rich for awhile then my plugs are fouled right? I'm going to change them when I get the car back.

 

triggz

Founding Member

May 15, 2002

1,218

0

37

Gadsden, AL

Jul 16, 2005

#12

• Jul 16, 2005

• #12

the stock fuel rail pressure should hover around 40psi regardless of throttle, 36-50 is average fluxuation.