Low BLMs at idle and cruise

[ross87t]

I have an LS1 meter, 36# injectors, Translator+, and extender chip 98 octane 23/21 (burned for alky).

The Scanmaster is showing an average of around 105 BLM value at idle and cruise (warm engine) It will even dip down into the 90's. At WOT and under boost, the BLMs go straight to 128 and stay there.
I assume the car is running rich at idle? It sure smells that way.

I tried lowering the fuel pressure from the recommended 45psi (line off) to 43. This didn't help. Next, I tried lowering the BLM value w/ the extender chip (cell 11). I lowered it from 8 to 6...no change...then I lowered to 4...nothing, so I raised it back to 8.

I haven't tried adjusting the T+ yet. Isn't there a "base" fuel setting on the T+ I can adjust? Should I lean it out 3%?
If I do lean the "base" setting out, will it also lean WOT out?

What other things could cause low BLMs?

Ross

 

[WarpSpeed]

a blm of 105 isn't bad at idle, or cruise, the computer just thinks the chip is calling for too much fuel, and the computer is adjusting using blms. Now, why does the computer think it's rich?
You should probably put the fuel psi back to where it was. tune fuel psi only at WOT.

 

[ross87t]

Originally posted by WarpSpeed
a blm of 105 isn't bad at idle, or cruise, the computer just thinks the chip is calling for too much fuel, and the computer is adjusting using blms. Now, why does the computer think it's rich?
You should probably put the fuel psi back to where it was. tune fuel psi only at WOT.

I did go ahead an put the fuel pressure back to the recommended 45 psi (line off).

How about the T+ "base" fuel setting? Should I pull some fuel out of it?

Thanks,
Ross

 

[wiked87gn]

leaky fuel pressure regulator or maf going bad..

 

[87GN]

Set your base maf to lean (2), it could be (1) I'm not sure and start parameter 11 at 0 and work yourself up. Reset the ECM before each change and watch the BLMs. If you don't reset it just take a little longer for BLMs to settle.

 

[wiked87gn]

oh yeah i forgot about that, set your T plus at 10% lean at idle and the parameter 11 on the extender to 2., every point you reduce on the chip is a 2% lean count so setting it to 2 on the chip would lean it out another 12% that should put you right around 120+ on the Blms if not then you have other issues..

Originally posted by 87GN
Set your base maf to lean (2), it could be (1) I'm not sure and start parameter 11 at 0 and work yourself up. Reset the ECM before each change and watch the BLMs. If you don't reset it just take a little longer for BLMs to settle.

 

[ross87t]

Let me see if I am getting this:

1. Set the T+ (dial inside the box) "base" MAF to 1 or 2. (What % lean is this?)

2. Start w/ parameter 11 (base fuel) on the chip at setting 0?

 

[ross87t]

Originally posted by wiked87gn
oh yeah i forgot about that, set your T plus at 10% lean at idle and the parameter 11 on the extender to 2., every point you reduce on the chip is a 2% lean count so setting it to 2 on the chip would lean it out another 12% that should put you right around 120+ on the Blms if not then you have other issues..

Also...if I set the T+ to 10% lean at idle, is it going to lean out WOT by 10% as well? Will I have to adjust the WOT setting to 10% rich to compensate for the fuel I pulled out of the base (idle/cruise) setting?

Thanks guys. I really appreciate the advise you all are throwing my way.

Ross

 

[wiked87gn]

no you dont have to adjust it, the 10% lean at idle only affect the idle not the WOT range there is also a knob inside the T plus that will allow you to give more fuel at WOT if need or vice-versa, look in the back of the little cover of the T plus the settings should be there it will tell you which setting is 10% lean and which is 10% rich. let us know how you do..

 

[VadersV6]

A few weeks ago when i installed my extender and 50's, I immediatelly had BLM's locked in at 90 at idle. The second I would give it some gas, they would jump up to 128. First I lowered the FP to 38. It didnt do anything cause I was so low on BLM's, to the point I was locked. I set the trans to 10% lean and that brought me up to about 93, but now my higher rpm BLM's were rising. You cant set base to lean without it affecting the whole maf curve. Note the translator doesnt say idle...it says base. Its your base curve. I brought my extender's BLM parameter down to 1 and that got me to about 110, but now my cruise BLM's were 140. Last weekend, I pulled the LS1 MAF and trans out and put the stock MAF back in. Now without even having a translator lowering my signal 10%, my BLM's came up to about 125 at idle, and about 133 at cruise. At this point, Ill just set FP till I get my cruise BLM's where I want them, and then Ill do the IAC reset procedure to try and reduce that idle/cruise BLM spread I have. So basically, either my translator or LS1 MAF has an issue. I just dont know which. Start looking in that direction.

 

[ross87t]

Originally posted by VadersV6
A few weeks ago when i installed my extender and 50's, I immediatelly had BLM's locked in at 90 at idle. The second I would give it some gas, they would jump up to 128. First I lowered the FP to 38. It didnt do anything cause I was so low on BLM's, to the point I was locked. I set the trans to 10% lean and that brought me up to about 93, but now my higher rpm BLM's were rising. You cant set base to lean without it affecting the whole maf curve. Note the translator doesnt say idle...it says base. Its your base curve. I brought my extender's BLM parameter down to 1 and that got me to about 110, but now my cruise BLM's were 140. .

Can't you just set the trans to 10% rich on the WOT setting to compensate for the 10% lean base setting?

 

[wiked87gn]

they have nothing to do with each other they are totally separate, base wont affect the WOT setting...

Originally posted by ross87t
Can't you just set the trans to 10% rich on the WOT setting to compensate for the 10% lean base setting?

 

[ross87t]

Well, I set the T+ base to 10% lean, and reset the computer, fired it up, and the BLMs stayed at 128 for about a minute or so, then starting settling down. They stayed around 115 for a while (I was driving the car around the neighborhood), then they finally settled back down into the damn 90's. This is pissing me off. Nothing I have adjusted has brought the BLMs up.

I guess I have a crappy MAF or something. This sucks.

On a side note, the car seems to be running fine, and it is hauling ass. 21psi, no knock..o2's in the low 800's.

Are the idle BLM's really that important to get up closer to 128? Any more than 10% throttle, and they jump to 128.

I just don't like the car running so rich at idle. It makes my close stink.

 

[wiked87gn]

can be leaky injectors, leaky fp regulator, bad ECU or bad MAF, check injectors, check fuel pressure regulator and see if pressure holds after you turn the car off, pressure should stay up for at least 30 to 40 minutes until it goes all the way down, could be your injectors are sticking, listen to them for clatter.. good luck.. you can also lower the setting on parameter 11 on the chip, to 0 see if that helps

 

[VadersV6]

Your cruise BLMs are where they should be. Just do the IAC reset procedure on gnttype.org. Just dont pull the ECM power wire for whatever reason. Maybe the reset will get your idle blm's in a better place. I also noticed an improvement in my bLM's after I changed the o2 sensor. If all else fails, try that.

 

[ross87t]

The O2 sensor is a brand new delco unit.

I tried setting parameter 11 to 0. It did nothing for the BLM numbers. I'll check fuel pressure after I turn the car off to see how long it holds.

I was planning on some 60's in the very near future to match the T63e that I just put on.

 

[VadersV6]

Mine was a brand new denso unit. Only 2 months old and I had never run race gas through it. the crosscounts even looked good. i just didnt know how much better they could be. I know bosch o2 sensors have a bad rep on here, but I think thats for guys running race gas. This sensor is much more active than the denso one I had.
Anyway, it sounds like something is majorly wrong. Does the part number on the chip correlate to the 36# injectors?

 

[ross87t]

Originally posted by VadersV6
Mine was a brand new denso unit. Only 2 months old and I had never run race gas through it. the crosscounts even looked good. i just didnt know how much better they could be. I know bosch o2 sensors have a bad rep on here, but I think thats for guys running race gas. This sensor is much more active than the denso one I had.
Anyway, it sounds like something is majorly wrong. Does the part number on the chip correlate to the 36# injectors?

I ordered the chip and T+ at the same time from Mike at Full Throttle Speed. We talked on the phone, and he did get all of my info, so the chip should be right. I am kind of worried that the MAF could possibly be bad, or the wrong unit all together. I see everyone saying "3.5 LS1 MAF". I really don't think the diameter of my MAF is 3.5" I think it is closer to 3". I have a couple of friends w/ LS1 cars, so I am going to borrow theirs this weekend, and see if there is a difference.

Ross

 

[ross87t]

PROBLEM SOLVED!!!

Swapped out the AC CR43TS plugs for some Autolite 24's. Maybe one or more of the AC plugs were bad.

Idle BLMs are now at 128-132. Cruise BLMs are around 128-138.
I drove the car around for 20+ minutes, and the numbers stayed. AWESOME!

19psi, no knock, .800 O2s

I want to raise the boost up to 21psi. Maybe that will bring the O2s to around the .760's. Hopefully, I won't see any knock either.

Ross

 

[ross87t]

I just wanted to add that this is a prime example of "start out with the simple stuff".

If you are having a problem, don't freak out. I was, thinking I'd have to replace the MAF, get the chip reburned, change the injectors, etc.

$12 and 20 minutes of work fixed this problem.

Ross