High BLM help

[JDEstill]

One of these days I'm going to get around to getting my car running right! I haven't had the urge to mess with it much lately, but I think I'm starting to get some energy back. So...

I've a got a weird BLM thing going on. Cells 0 and 15 (idle and WOT) are both pegged at 160. All the other cells in the BLM table look pretty good. Does this ring any bells with anyone for a potential cause?

Car seems to drive okay for the most part, although I get a little detonation earlier than I'd like, around 14-15 psi. Doesn't smell really rich at idle (at least not that I've noticed), haven't noticed any billowing black clouds of smoke at WOT either (but then I'm not usually looking in my rearview mirror while flooring it). The inside of the exhaust does tend to be a bit sooty however.

Tried two different chips, exact same thing with both. One chip is Jay's, about 4 or 5 years old by now I guess, the other is from a nameless member of this board who kindly sent me a chip file that he had spent many hours dialing in on his car for these red stripe injectors. Now that I think about it, I did at one time have a semi-experimental Thrasher for red stripes, and it always read really lean at idle, even after Scott added a bunch of fuel to it for me. I had to really crank up the fuel pressure to get some decent idle O2 readings. This was... 3 or 4 years ago I guess.

I do have some oil showing up in the intake. I don't have that many miles on this rebuild, and I have found oil on the top of my Power Plate after not very many miles. The up pipe and throttle body is dry as a bone, so I'm thinking it is getting sucked in through the PCV. I do have a stock valley pan in there. I've wondered about a leaking intake gasket (I do have ported heads BTW), but I put a vac gauge on it and it was pretty steady. Thought it would be pulsing if I had that particular problem. How else could I diagnose that? Would an intake gasket leak possibly cause this BLM behavior?

Exhaust system could easily have a leak, the exhaust ports have been opened up within an inch of their lives, and I would not be surprised at all to find a leak there. Don't hear anything, but haven't closely investigated either. Could an exhaust leak cause such weird BLMs?

Oh yeah, I also did Bruce's MAF relocation project a while back, put the MAF right on the throttle body. Had to move it back due to hood insulation pad interferance, but before I did I checked the BLMs again, and there was no change at all. So the BLM problem is not due to an air leak upstream of the throttle body.

Combo - rebuilt shortblock, 206/206 cam, ported heads, TE-60, red stripes, Translator+, I guess that's the highlights.

If anyone has any good ideas, let me hear them!

Thanks

John Estill

 

[ACME RACING]

BLM

When i put the 3" SS Impala MAF sensor and Translator my BLM's went up to 142-151 , put stock back on, went down to 128.......I run the SS MAF now all the time and passed emissions like a new Honda....It runs lean at part throttle ,but riches up at full throttle....So mine has been doing ok keeping the spark plugs clean ... alan

 

[JDEstill]

no helpful ideas from anyone? pretty please?

 

[WarpSpeed]

Sounds like a bad MAFs to me.

 

[JDEstill]

Hmmm, I hadn't thought of that. I don't remember now what things looked like with the stocker on there, that'll be easy to try and see if it changes any. I don't think that's it, but it's worth a shot. I have fiddled with the Translator settings to see if that would help, but so far it hasn't.

Any other thoughts?

John

 

[GNVAIR]

I had problems with high blms for the longest time. It took me months to get a handle on itl. I checked fuel supply, ignition, etc.
My blm's would gradually creep to 150 when idling at a traffic light. I spoke to many people and the 2 things that fixed mine was removing the 1 way check valve I had on the pcv line AND richening up the idle setting on the translator from position 3 (for the 3" mass air) to position 4. With these 2 changes, I see blms of approx 118-122 at idle which is acceptable to me.
Lately I have noticed that the reading is dependent on coolant temperature since the blm's tend to creep up a little when it is hotter. I am running a JL 93 street chip with 30lb injectors. I will be switching to 55's with an Extender chip shorty and will experiment to see how they work out.

 

[Steve Wood]

Anything unusual about the pws when in these cells?

 

[JDEstill]

Thanks for the advice Lee, I'll check some of that out. I just looked at an old DS file, and I didn't have this problem a year ago or so, so maybe it is translator related. I'll get my old MAF on there tomorrow and see what it does.

Steve, what kind of weirdness are you thinking of? Here's a DS file, mostly just idling I think:
http://pages.prodigy.net/buickv6/_images/newchip.ds

John

 

[Steve Wood]

I was wondering if the pws continued to increase or flattened out in cell 15

 

[TurboTR]

I dunno John, I think if all else is ok what I'd do in that case is just adjust the inj constant or maybe fuel pressure until the idle cell is back near nominal, at least well within control system +/-range. Then not really worry about the other cells too much, other than the cruise area. Seems like mine went haywire too when we put the ported irons and all on, but back then we didn't have any info available other than ALDL scanners. The car ran fine IMO, even though the BLM's were not perfect. No cat of course. JMO.

I hope you bring it to the mini nats Sun! And that maybe there's a FAST ecu in your future

TurboTR

 

[ijames]

Having BLM 15 get bigger and bigger just seems to be a fact of life with larger injectors, relative to the midrange cells. High BLM 0 that used to be okay is a classic symptom for an exhaust leak before the O2 sensor sucking in air, fooling it into thinking the engine is lean. Also, using "slow" injectors will make blm 0 bigger (like low impedance injectors with saturated drivers instead of peaknholds), but redstripes aren't slow.

 

[JDEstill]

hmmm good thoughts. I need to get my car inspected, and I'd feel better about passing the sniffer part if the idle BLM wasn't pegged like it is. Hopefully I'll get to do some checking tomorrow, although now it looks like I've got to work at least a few hours So far I've got MAF, O2 sensor, and exhaust leak to check into. Anything else?

John