Hot/cold BLM problem...
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From: 600 yds out
Car: Bee-Bowdy
Engine: blowd tree-fity
Transmission: sebin hunnerd
Axle/Gears: fo-tins
Hot/cold BLM problem...
When I first drive the van in the morning the BLM's will show lean (134-136) all over.
If I let the engine warm up, then clear all the data tables in WinALDL, the BLM's will show stoich to slightly rich (124-128) if I continue driving.
Is there any way to add fuel in closed loop at intermediate coolant temps?
I found this in my hack (7747 ECM) a while ago...and added it to my WinBin ecu. I do not fully understand it so I haven't messed with it. BUT I think it may be what I'm looking for...
I just thought of something...maybe the AE vs. coolant temp is off?
If I let the engine warm up, then clear all the data tables in WinALDL, the BLM's will show stoich to slightly rich (124-128) if I continue driving.
Is there any way to add fuel in closed loop at intermediate coolant temps?
I found this in my hack (7747 ECM) a while ago...and added it to my WinBin ecu. I do not fully understand it so I haven't messed with it. BUT I think it may be what I'm looking for...
Code:
;---------------------------------------------
; O2 SENS VOLTAGE BIAS FOR COLD OP'S
;
; TBL = VDC * 230.4
;---------------------------------------------
LD4D9 FCB 192 ; 105 Deg c, UPPER TBL LIMT
ORG $04DA ; mVDC COOL c
;---------------------------------
LD4DA FCB 0 ; 0.0 -40.0
LD4DB FCB 0 ; 0.0 -7.0
LD4DC FCB 0 ; 0.0 6.5
LD4DD FCB 0 ; 0.0 16.0
LD4DE FCB 4 ; 17.4 24.0
LD4DF FCB 4 ; 17.4 31.0
LD4E0 FCB 4 ; 17.4 37.3
LD4E1 FCB 4 ; 17.4 43.7
LD4E2 FCB 4 ; 17.4 49.7
LD4E3 FCB 4 ; 17.4 56.5
LD4E4 FCB 4 ; 17.4 63.5
LD4E5 FCB 4 ; 17.4 71.5
LD4E6 FCB 0 ; 0.0 80.5
;--------------------------------------------- 
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Re: Hot/cold BLM problem...
Originally posted by V8Astro Captain
When I first drive the van in the morning the BLM's will show lean (134-136) all over.
If I let the engine warm up, then clear all the data tables in WinALDL, the BLM's will show stoich to slightly rich (124-128) if I continue driving.
Is there any way to add fuel in closed loop at intermediate coolant temps?
I found this in my hack (7747 ECM) a while ago...and added it to my WinBin ecu.
When I first drive the van in the morning the BLM's will show lean (134-136) all over.
If I let the engine warm up, then clear all the data tables in WinALDL, the BLM's will show stoich to slightly rich (124-128) if I continue driving.
Is there any way to add fuel in closed loop at intermediate coolant temps?
I found this in my hack (7747 ECM) a while ago...and added it to my WinBin ecu.
The manifold as it heats up will always dither the atomization, vs vaporization ratio of the fuel in the manifold, and skew the BLs to some degree. That's in part the reason for so much water jacketing under the plenum/runners on a TBI manifold.
On my car, I see the MATs lagging the coolant alot during warmup, and then slowly climb to about 40dF less then coolant. But on a warm summer's day they can match coolant temp, and higher. A 60dF relavent MAT temp will skew the BLs.
And, the timing reguirements also change slightly as a function of MAT.
Nice seeing ya get to the level of looking at oem type problems, and you're welcome....
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From: 600 yds out
Car: Bee-Bowdy
Engine: blowd tree-fity
Transmission: sebin hunnerd
Axle/Gears: fo-tins
Gotcha. So I should really wait for the engine to get nice and warm before I take the BLM's into account.
The heads/intake I have do not have an exhaust cross-over. I'm sure that the manifold is staying really cold...
The heads/intake I have do not have an exhaust cross-over. I'm sure that the manifold is staying really cold...
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Originally posted by V8Astro Captain
Gotcha. So I should really wait for the engine to get nice and warm before I take the BLM's into account.
The heads/intake I have do not have an exhaust cross-over. I'm sure that the manifold is staying really cold...
Gotcha. So I should really wait for the engine to get nice and warm before I take the BLM's into account.
The heads/intake I have do not have an exhaust cross-over. I'm sure that the manifold is staying really cold...
You can waste alot of time looking to stay at 128s. And have better used the time to learn other things about tuning. 115s to 140s are OK.
Never assume.
At low flow periods like in a drive thru line where your at idle, there just isn't enough air flow thru the manifold to cool it at all.
When thinking about the manifold remember the oil splashing against it is much hotter then coolant. Hmmm, hint, hint.
If you look at the air gap manifolds the point is to keep the hot oil off the bottom of the manifold.
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From: 600 yds out
Car: Bee-Bowdy
Engine: blowd tree-fity
Transmission: sebin hunnerd
Axle/Gears: fo-tins
yes, yes. I forgot about the oil flying around in the valley...
I've got all the BLM's in the 125-133 range. I like to keep them on the 125 side just in case. We all know spark plugs are cheaper than pistons!
I'm still trying to figure this aweful off-idle bog. Seems to be the worst from a rolling stop. When the manifold vacuum jumps from 45 kPa to 80 kPa. I've been tuning real slow, working things back and forth...I'm pretty sure it was like we discussed before. The timing isn't dropping out quick enuf. I also have a feeling there was more AE needed...
...it's gettin there
I've got all the BLM's in the 125-133 range. I like to keep them on the 125 side just in case. We all know spark plugs are cheaper than pistons!
I'm still trying to figure this aweful off-idle bog. Seems to be the worst from a rolling stop. When the manifold vacuum jumps from 45 kPa to 80 kPa. I've been tuning real slow, working things back and forth...I'm pretty sure it was like we discussed before. The timing isn't dropping out quick enuf. I also have a feeling there was more AE needed...
...it's gettin there
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From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Originally posted by V8Astro Captain
yes, yes. I forgot about the oil flying around in the valley...
I've got all the BLM's in the 125-133 range. I like to keep them on the 125 side just in case. We all know spark plugs are cheaper than pistons!
I'm still trying to figure this aweful off-idle bog. Seems to be the worst from a rolling stop. When the manifold vacuum jumps from 45 kPa to 80 kPa. I've been tuning real slow, working things back and forth...I'm pretty sure it was like we discussed before. The timing isn't dropping out quick enuf. I also have a feeling there was more AE needed...
...it's gettin there
yes, yes. I forgot about the oil flying around in the valley...
I've got all the BLM's in the 125-133 range. I like to keep them on the 125 side just in case. We all know spark plugs are cheaper than pistons!
I'm still trying to figure this aweful off-idle bog. Seems to be the worst from a rolling stop. When the manifold vacuum jumps from 45 kPa to 80 kPa. I've been tuning real slow, working things back and forth...I'm pretty sure it was like we discussed before. The timing isn't dropping out quick enuf. I also have a feeling there was more AE needed...
...it's gettin there
Need to work at getting the fuel to move on and into the chambers. Plumbing coolant through the manifold x-over can do wonders (dang, another secret out
). A hotter spark helps too, ignites a leaner mixture easier (a $16 oil-filled canister coil). Can also pre-heat the air. RBob.
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From: Shanghai PRC
I am having a similar problem now with mine, particularly if I try to drop the clutch (spin the tires). I am thinking I need to increase the differential map adder (pump shot) since the main thing that happens when I drop the clutch is a change in MAP. TPS doesn't change much. Could this help your off-idle bog? Or, do you have an automatic?
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From: 600 yds out
Car: Bee-Bowdy
Engine: blowd tree-fity
Transmission: sebin hunnerd
Axle/Gears: fo-tins
I'm not sure if I have too much AE vs. MAP, or not enuf. I cut the values in half in that table and I'm going to drive it tomorrow. We'll see what kinda results I get.
It's a little tough to see what's going on when the data to the laptop refreshes so slow. Alot of times the bog happens so quick the data "skips" over it. I guess I could hook up a vacuum gauge to see what's going on...
It seems like when it bogs real hard the inj pw is up really high, and when it falls down a bit the engine comes to life again.
I dropped off some timing...I had too much in at 800 rpm x 80 kpa.
It's a little tough to see what's going on when the data to the laptop refreshes so slow. Alot of times the bog happens so quick the data "skips" over it. I guess I could hook up a vacuum gauge to see what's going on...
It seems like when it bogs real hard the inj pw is up really high, and when it falls down a bit the engine comes to life again.
I dropped off some timing...I had too much in at 800 rpm x 80 kpa.
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From: great lakes
you might want to check out mondello industrys. they make a power cone. its not the greatest for top end airflow itll actually hurt the flow. but what it does do is create a very small vortex that will whip the air about and help fuel stop puddling.just some thoughts. also you might be bogging the motor with to much AE but on a counter thought how much timing are you running in those regions ? rpm vs kpa.
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From: 600 yds out
Car: Bee-Bowdy
Engine: blowd tree-fity
Transmission: sebin hunnerd
Axle/Gears: fo-tins
At 800 rpm x 80 kPa (where the bog usually occurs I think) I'm running 11°.
Tomorrow I will see how my AE changes affects things.
Tomorrow I will see how my AE changes affects things.
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Originally posted by V8Astro Captain
I'm not sure if I have too much AE vs. MAP, or not enuf.
I'm not sure if I have too much AE vs. MAP, or not enuf.
Blindly changing numbers to see where you are, is a tough way to get anywhere. I only mention this since I've spent sooo much timing woriking on drivibility.
Using a 40 LED (Bruce Ros) display makes working thru this almost too easy.
But the sensors are kind of hard to get right now.
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Originally posted by V8Astro Captain
At 800 rpm x 80 kPa (where the bog usually occurs I think) I'm running 11°.
Tomorrow I will see how my AE changes affects things.
At 800 rpm x 80 kPa (where the bog usually occurs I think) I'm running 11°.
Tomorrow I will see how my AE changes affects things.
Really?.
Just blippin the gas, or with load?.
How far away it the sensor?.
Type of line going to it.
Manifold, cam?.
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From: 600 yds out
Car: Bee-Bowdy
Engine: blowd tree-fity
Transmission: sebin hunnerd
Axle/Gears: fo-tins
Originally posted by Grumpy
You can get to 80 K/Pa at 800 ROM?.
Really?.
Just blippin the gas, or with load?.
How far away it the sensor?.
Type of line going to it.
Manifold, cam?.
You can get to 80 K/Pa at 800 ROM?.
Really?.
Just blippin the gas, or with load?.
How far away it the sensor?.
Type of line going to it.
Manifold, cam?.
I think it was hitting that load range because the timing and fuel were WAY off. I had too much timing and too much AE vs. MAP. it drives alot smoother now, but it's not perfect.
The O2 sensor is about 20" down the pipe from the engine. It's a 3 wire heated O2.
I'm running an Edelbrock 2101 Performer dual plane. I have a 3/4" thick TBI adapter on top of it.
The rest of my engine goodies are in my signiture. I think I should add that the cam is retarded 2°.
I would love to have a WB O2. My electronics skills are not THAT great tho. I've tinkered with some old ECMs...trying to install a ZIF socket. That didn't turn out so well. That was with a $10 ECM too, I'm not too sure about spending alot of $$$ on something I can't build!
Last edited by V8Astro Captain; Mar 6, 2003 at 06:12 PM.
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