Lean condition.

RED LS1

SENIOR MEMBER
Dec 31, 2001
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Philly Pa
I got my car running pretty damn good for my liking. On the street I can make pulls anywhere at any time and get a 720-780 reading with zero KR depending on where the Alky knob is. I couldn't ask for a better running car. Recently I made 3 passes at the track with it and a problem has occurred.

First, My combo. Stock motor with 60 lbs injectors and TT chip. All the usual small supporting mods. 6262 turbo, PTE SLIC intercooler, TA 3" DP and Pypes Cat back and Alky injection with M1. Boost is at 26 psi steady and trans and converter are untouched, bone stock.

On the first pass (couple weeks ago) the car seemed to run perfect down the track and felt good. Replay on the SM showed 6* of KR and a lean o2 in the 500's. I said oh crap and went home. I realized on the ride home the Alky knob was on 5 and since this was the first full 1/4 pass with this car is clearly needed 6-6.5. oh well.

Came back last night. Knob on 6.5 to be safe. car ran clean but flashed 720 and 1.9 through the traps. was clean up until that point. I went up a touch on the alky close to 7 to be safe. Made a second pass. After it shifted into second gear I heard the car pinging pretty bad. Don't ask me why but I stayed in it because i'm an idiot and have no will power. It felt like a decent pass. when I hit recall, 620 and 10.0* !!

I'm looking for some ideas to look for. I haven't checked the fuel pressure on the car in a while so that should be looked at. I may buy a hood gauge for now to see what's going on. Also, the chip I have in there I got second hand. It's a 5.7 chip 22/20 22-24psi. I'm thinking about having it reburnt or get a new one for the car to rule that out.

any other suggestions welcome. I thought maybe false shift knock due to the tight converter and tight shift but this seems more like a lean condition to lose fuel like that.
 

TRICKSIXPA

East Coast Go fast with class club MAGNA!!!
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May 27, 2010
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First thing you need to check is fuel. Voltage to pump and boost to FP ratio.
What pump is in there and how old. I’m guessing you have a Hotwire on it.


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RED LS1

SENIOR MEMBER
Dec 31, 2001
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you fix low 02 with fuel not alky ..add fuel with the chip
I can certainly do that and that's a good point. I've seen Julio make a similar case in past threads as well. I figured the 20% out of the chip setting was a pretty standard thing across the board.
 

RED LS1

SENIOR MEMBER
Dec 31, 2001
676
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Philly Pa
First thing you need to check is fuel. Voltage to pump and boost to FP ratio.
What pump is in there and how old. I’m guessing you have a Hotwire on it.


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The pump was in the car when I got it. I was told it was a replacement 240 or 255 of some sort. I never messed with it because the car always had great numbers on the street in shorter spurts. It does have a hotwire kit that I put on. The pump is at least 3 years old, possibly 4.
 

TRICKSIXPA

East Coast Go fast with class club MAGNA!!!
Staff member
May 27, 2010
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CHADDS FORD ,PA
There you go at the very least replace it with a new pump they cost under $100. You are definitely gonna max out the pump once you get your combo together. That turbo is a 10sec turbo with the right convertor. Check voltage to the pump, and fuel pressure rise with boost.


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RED LS1

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Dec 31, 2001
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That turbo is a 10sec turbo with the right convertor.

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I know the set up should go much faster with my combo and boost. It's going 11.80-11.90 at 116mph consistently. But with the stock converter I can only get 2-3psi with the Ebrake and 1.8 - 1.9 60 fts. I have a converter shop and a converter for it but I just didn't feel like doing the swap until absolutely necessary. I think i'm at that point now. Between that and fixing this condition it will be a fast car. I'm still happy with it.
 

scgnx2

Active Member
Jan 24, 2009
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I have been running a KB hood mounted fuel pressure gauge for the last 20 years. It has proved to be invaluable in detecting fuel pump failures, fuel regulator issues, fuel pump relay failures and me from blowing the motor up.
 

Bullnerd

Active Member
Jan 16, 2005
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I'm curious and don't want to derail this too much, but I am about to have a similar setup and have to buy injectors and a new pump.

What would you guys recommend?

Are 60's sufficient for 6265s turbo? Street car for the most part, might go to Atco once in a while to run with Speed racer.

255 or 340 pump?

Id like to use the new Racetronix pump harness and it would also be nice to take advantage of their sale right now.
 

RED LS1

SENIOR MEMBER
Dec 31, 2001
676
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Philly Pa
Why not put a WBo2 in it and then tune it more accurately

I have no debate for that. Probably a great idea. A Powerlogger is another good idea. I actually have a Fast XFI I just haven't committed to putting it in yet. The car was 100% perfect running car for a long time and this is all new. Only happened at the track.
 

RED LS1

SENIOR MEMBER
Dec 31, 2001
676
97
28
Philly Pa
I'm curious and don't want to derail this too much, but I am about to have a similar setup and have to buy injectors and a new pump.

What would you guys recommend?

Are 60's sufficient for 6265s turbo? Street car for the most part, might go to Atco once in a while to run with Speed racer.

255 or 340 pump?

Id like to use the new Racetronix pump harness and it would also be nice to take advantage of their sale right now.


I think 60's are a great injector and have had them in multiple cars. I see many people will tell you now to go with 80's and that there's no driveability difference vs the 60's but you have more injector to grow into down the road. I think that's a fair argument and credible. My goals for this car are really reasonable I'm only looking for reliable mid elevens and i'm good. It's already making the MPH I wanted just need a converter to get off the line.
 
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Bullnerd

Active Member
Jan 16, 2005
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I think 60's are a great injector and have had them in multiple cars. I see many people will tell you now to go with 80's and that there's no driveability difference vs the 60's but you have more injector to grow into down the road. I think that's a fair argument and credible. My goals for this car are really reasonable I'm only looking for reliable mid elevens and i'm good. It's already making the MPH I wanted just need a converter to get off the line.
Yeah, I think i'm going to go with 60s (already have a TT chip, lost the injectors in a fire) and a 255 pump. That should work on stock lines for now.
 
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MikeS

Active Member
Oct 30, 2012
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For the small price difference, go 80's and Walbro 450 in the tank. And like turbo nasty said, get the wideband o2 sensor so you can tune with modern technology.
 
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SCOOBY DOO

Stock Junk Rules!
Feb 18, 2007
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60's...Erics chip...a fresh 255...alky with a good alky pump will take you way into the 10's...or faster. Reading Erics or Julios instructions will tell you to keep the 02's in the 780's. Read Erics instructions for his chip...that's why he sends them along with his chips. Julio has a sticky in the Alky Section on how to set up his kit and tune it. And get Powerlogger. You've prolly pounded your con rod bearings into tinfoil with the KR you've thrown at it. I'm surprised the head gaskets are in it. My YouTube channel is in my sig.
 
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captndave737

Well-Known Member
Feb 14, 2006
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How much alky was in the tank? If I have less than half the low level light comes on during hard acceleration unporting the pick up. That would mean no alky getting into the intake and lots of knock.
 

Mr.Spool

Well-Known Member
Nov 6, 2006
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I got my car running pretty damn good for my liking.
what you did was put it in headgasket territory,those o2s dont provide a cushion at all,there isnt enough fuel for the 1/4 there.the car should never see knock and mv should never be that low.
 

Mr.Spool

Well-Known Member
Nov 6, 2006
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On the first pass (couple weeks ago) the car seemed to run perfect down the track and felt good. Replay on the SM showed 6* of KR and a lean o2 in the 500's. I said oh crap and went home. I realized on the ride home the Alky knob was on 5 and since this was the first full 1/4 pass with this car is clearly needed 6-6.5. oh well.

Came back last night. Knob on 6.5 to be safe. car ran clean but flashed 720 and 1.9 through the traps. was clean up until that point. I went up a touch on the alky close to 7 to be safe. Made a second pass. After it shifted into second gear I heard the car pinging pretty bad. Don't ask me why but I stayed in it because i'm an idiot and have no will power. It felt like a decent pass. when I hit recall, 620 and 10.0* !!
moving your alky knob a tiny bit is not enough,the car is knocking on every hit.you need to keep you foot out of it and look at fuel pressure and alky pressure if all is well,then add wot fuel in the chip leave the knob on 6,the volume should take the knock away.
 

ttypewhite

Well-Known Member
Oct 1, 2001
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Toronto
Just food for thought on your alky knob. That doesn't control your volume... Your volume will remain the same on the #1 setting on the dial to the very last setting. All the knob controls is how fast the alky ramps in, not the amount of alky the motors see's. As mentioned before in this thread, you need to add more fuel from your chip to compensate for the lean condition, or run a test on your alky pump to make sure it's up to the task at hand.