Rich idle and BLM help please>>

[ohiogn]

Ok, I have been trying to track down a rich idle condition and recently had a chance to look at my BLM number. When warmed up and idling, the BLM shows 105. What does this tell me and what should I look for to bring it back to the proper 128 number?

Thanks

 

[Fred 86 GN]

It tells me that you have a set of 009 injectors and Reds chips! My combo is very close to yours, and I see the same level of blms with Reds and JL chips set at fuel pressures per their recommendations. Red and co. will tell you that as long as the blms are not bottomed out, that the ECM is still in control and everything is fine. This is true for the most part. No real need to get the blms really close to 128.

Course if you take out some fuel pressure (where is yours set?) then the idle blms will look better, but you will probably be lean at WOT. At least my DirectScan told me that was the case when I lowered my fuel pressure. Better to "rich" at idle than lean at WOT!

What are your o2's at WOT? Or the EGT values? Either of those (fresh O2 of course) will let you know if your WOT is rich or lean.

HTH

 

[ohiogn]

O2's are around .780-.790 at WOT. I think a vacuum leak may be partially responsible. Actually, I put one of Jim Testa's chips in and took Red's out. Do you see black smoke if you rev it while idling?

 

[ohiogn]

Forgot to say it acted the same with either chip.

 

[TurboJim]

Originally posted by ohiogn
Forgot to say it acted the same with either chip.

Really....hmm.....

Black smoke with MINE too? Hmmm...something weird there. You missing both MAF screens? My chip isnt set up to run that way. Need one at least. What is yer idleing fuel pressure. I like them set to 35-38 vac ON.

 

[ohiogn]

Jim...it is your street chip. FP line on is about 40psi. Line off is about 38. Not sure about the MAF screens....I bought it mostly the way it is...

 

[gnXfan]

I was seeing 90 at idle with 009s and red's chip. 90! Switched to Jim's and with no other changes got up to 115. Now depending on where I set the fp I can see anywhere from 113 - 123 or so. Great great chip!

 

[TurboJim]

Originally posted by ohiogn
Jim...it is your street chip. FP line on is about 40psi. Line off is about 38. Not sure about the MAF screens....I bought it mostly the way it is...

Wait, you saying FP DROPS when you attach vacuum? Or you just mistyped? Drop it to 35 VAC ON and see what it looks like.

 

[ohiogn]

Mistyped. I wonder how bad WOT will be affected if I drop it to 35psi...... Guess I'll give it a shot and watch the Scanmaster!!!

Thanks for the advice....

 

[TurboJim]

Originally posted by ohiogn
Mistyped. I wonder how bad WOT will be affected if I drop it to 35psi...... Guess I'll give it a shot and watch the Scanmaster!!!

Thanks for the advice....

I set my chips up a little on the fat side at WOT to take into account a cold day, or raising the boost a few psi, or a WG hose popping off and giving you a little before she leans out. I dont think WOT will be an issue at all. What has cell 16 learned to?

Drive,roll in approx 1/2 or so throttle and see what BLM is (thats cell 15, dont go more than 3/4 throttle or BLM lock, if installed, will show 128)

 

[ohiogn]

I'll give it a try tonite....

 

[Turbojorge]

Originally posted by Fred 86 GN
Better to "rich" at idle than lean at WOT!

HTH

Yup. Same thing here with the RA/009 combo, but I refuse to live with it. Thats why I'm going to have Jim burn me a bad ass steet chip.

I already have one of his high timing race chips and my car ran like a wild Ape with it when I tried it on. Still alot of tunning left so mid to high 11's are starting to jump in my mind. Thanks Jim.

 

[TurboJim]

Originally posted by Fred 86 GN
Better to "rich" at idle than lean at WOT!

BUT!!! Sometimes too high fuel pressure can cause LEAN WOT. Depends if there is a BLM lock installed, and WHERE the BLM is lowked TO. Why not simply get the car rihgt instead of a compromise. The car shouldnt be fat at idle, nor lean at WOT.

FWIW: having fuel pressure too high can and WILL cause a tip in hesitation/sag when you cross a real LOW BLM cell to a normal BLM cell. Say cell 0 is 100 and cell 1 is 129, there will be a rich tip in, which is why I suggest tuning so the BLM grid AVERAGES as close to each other as possible. Dont forget there are 16 cells there, dont concentrate on just 1.

 

[ohiogn]

ok....now what??

Jim,

I tried lowering the FP (line on) to 36 and guess what??? Either my gauge is broke, or my regulator is bad because it WILL NOT go lower than 38psi no matter how far out I turn the adjustment screw..... WTF is up with that??? One thing after another....

 

[ohiogn]

...and yes....the FP DROPS when I attach vacuum. It was at 44 line off, with vacuum it dropped to 40psi

 

[ohiogn]

ttt

 

[Eric Stage I]

You could check your AF (airflow) number on the scanmaster, warmed up at idle in park. It typically should be about 5-6. If its higher, the computer will calculate for more fuel, then the oxygen sensor will see the richness and the blm will come down to compensate.

 

[Ken Cunningham]

I second Eric Stage 1. I have been chasing the same problem in my car for a couple of years (!) With a Thrasher, my blms drop down to 105 in most driving situations. With another chip I tried (either JC or RA, I forget which) the blms go as low as 95, and my car goes right down to that level. The exact same fuel injectors and Thrasher chip were previously in my GN and worked just fine. I have fixed all exhaust leaks, replaced the O2 sensor, tried to bring the fuel pressure down, tried fuel pressure up, nothing seems to work. My maf reads 7 at hot idle, and one of the TR gurus in this area (Neil S.) suggested that a maf that's even slightly mis-calibrated will screw up your air/fuel ratio.

 

[ohiogn]

What about the prob with my FP not going below 39psi or so? Keep me updated on your progress if you can...... Jim, are you still out there?