Starting to tune my 305TBI
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Car: 1992 Firebird
Engine: 350TBI
Transmission: 700r4
Axle/Gears: Ford 9in 4.10
Starting to tune my 305TBI
Its got 113 heads, Comp Cams XFI268 Camshaft, exhaust, and just regular AC Delco spark plugs, regular 305 injectors, Edelbrock 3704 intake manifold
I reverted back to the factory tune and I bumped my fuel pressure up to around 15psi and it seems to like it, maybe a tad rich.
VE learn is a lot of -
Attached is a picture of the tune as it stands now after 6 VE learns
I started with the standard EBL_F_0016.BIN
I have no EGR or AIR and I removed both from the ECM. Check engine light only comes on sometimes, normally at low speeds and its Code 33. Other then that no check engine or error codes. Engine idles decently but when you go from a stop it jerks a little bit until you get to about 20mph or so. Engine has heat issues right now [fan isent working unless AC is on, got to fix that]
I reverted back to the factory tune and I bumped my fuel pressure up to around 15psi and it seems to like it, maybe a tad rich.
VE learn is a lot of -
Attached is a picture of the tune as it stands now after 6 VE learns
I started with the standard EBL_F_0016.BIN
I have no EGR or AIR and I removed both from the ECM. Check engine light only comes on sometimes, normally at low speeds and its Code 33. Other then that no check engine or error codes. Engine idles decently but when you go from a stop it jerks a little bit until you get to about 20mph or so. Engine has heat issues right now [fan isent working unless AC is on, got to fix that]
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Re: Starting to tune my 305TBI
Heres a picture showing the differences between the Stock BIN and my current one after some VE learns.
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Re: Starting to tune my 305TBI
Heres how my VE tables look now, after many VE learns and some manual smoothing.
Im now using the LG4 SA tables that come with the EBL. Not getting any knock, but it did make my idle rougher and it now dies while in gear alot more now [only when at a stop light, not when giving it gas]
Im now using the LG4 SA tables that come with the EBL. Not getting any knock, but it did make my idle rougher and it now dies while in gear alot more now [only when at a stop light, not when giving it gas]
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Re: Starting to tune my 305TBI
In the VE Learn are you using any smoothing? I would set it to a value of 4 to 6 to take the rough edges off. You can smooth the exisitng VE tables by starting a VE Learn then stopping it. No need to run any data through it.
Are you using a stock GM ignition module? If so check and post back the 3 digit code on the module (048, 036, 369, ...). Dependent upon which module you are using there is better SA tables that can be used.
Also note that if the SES lights for 33, MAP high, you should stop the VE learn. The reason is that the MAP value is made up by the ECM (a default mode). Once the tune is closer the MAP high error should go away. If it doesn't there is a calibration parameter that can be changed.
MALF33 - MAP Hi BARO Limit (1bar)
RBob.
Are you using a stock GM ignition module? If so check and post back the 3 digit code on the module (048, 036, 369, ...). Dependent upon which module you are using there is better SA tables that can be used.
Also note that if the SES lights for 33, MAP high, you should stop the VE learn. The reason is that the MAP value is made up by the ECM (a default mode). Once the tune is closer the MAP high error should go away. If it doesn't there is a calibration parameter that can be changed.
MALF33 - MAP Hi BARO Limit (1bar)
RBob.
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Re: Starting to tune my 305TBI
I applied some smoothing now to the VE tables.
I have ignition module 369.
Thanks for the help
Also any way to change the idle in gear to like 600 or 700?, so the car wont die at red lights
I have ignition module 369.
Thanks for the help
Also any way to change the idle in gear to like 600 or 700?, so the car wont die at red lights
Last edited by Timothayyy; 12-17-2008 at 01:23 PM.
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Re: Starting to tune my 305TBI
OK, with the 369 module (which is the better of the modules) don't use the _1001 calibration. It will have way too much SA at WOT. I'll send a better calibration for you.
To change the idle speed there are two tables, one for park/neutral and the other for in-drive:
IAC - Idle Speed: Drive
IAC - Idle Speed: Park/Neut
Just set the values to the idle speed you want. Note that the park/neut idle should be higher then the in-drive idle speed. Otherwise it will/can stall when dropped into gear.
With that cam may want an idle speed of 750 or so (in drive). Then 775 in park/neut.
The VE tables definately look better. It'll run smoother too. At the same time they could use some additional work. On the low speed table the 400 RPM (and maybe the 500 & 600 RPM) row needs to be lowered. Since the engine rarely runs there no learning can take place. Use the mouse on the graph and pull those areas down to the same values as where the VE has learned in.
Basically level it out. This will help when the engine RPM dips down as it won't flood out.
To get a good VE learn need to go easy on the throttle. Holding it still is the best way to get good learns. The current low speed VE tables has some high & low points, which may be caused by too much throttle movement.
For the low speed stuff I use industrial parks after hours and on weekends. Can crawl around allowing time for the low speed to learn in. Use the smoothing at low values (2 - 6) for the most part.
RBob.
To change the idle speed there are two tables, one for park/neutral and the other for in-drive:
IAC - Idle Speed: Drive
IAC - Idle Speed: Park/Neut
Just set the values to the idle speed you want. Note that the park/neut idle should be higher then the in-drive idle speed. Otherwise it will/can stall when dropped into gear.
With that cam may want an idle speed of 750 or so (in drive). Then 775 in park/neut.
The VE tables definately look better. It'll run smoother too. At the same time they could use some additional work. On the low speed table the 400 RPM (and maybe the 500 & 600 RPM) row needs to be lowered. Since the engine rarely runs there no learning can take place. Use the mouse on the graph and pull those areas down to the same values as where the VE has learned in.
Basically level it out. This will help when the engine RPM dips down as it won't flood out.
To get a good VE learn need to go easy on the throttle. Holding it still is the best way to get good learns. The current low speed VE tables has some high & low points, which may be caused by too much throttle movement.
For the low speed stuff I use industrial parks after hours and on weekends. Can crawl around allowing time for the low speed to learn in. Use the smoothing at low values (2 - 6) for the most part.
RBob.
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Re: Starting to tune my 305TBI
I copied all the SA tables except launch mode which I left stock.
For the idle, I just added 100 to both tables.
Ill test it out later today, and let you know how it runs.
For the idle, I just added 100 to both tables.
Ill test it out later today, and let you know how it runs.
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Re: Starting to tune my 305TBI
It dident like those SA tables you sent me.
I could barely get it out of the driveway, it kept dying so often. WOT felt a lot weaker.
I could barely get it out of the driveway, it kept dying so often. WOT felt a lot weaker.
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Re: Starting to tune my 305TBI
That doesn't make any sense. Is the distributor base timing set the same as the initial timing value in the calibration? Did you look at the tables to see that they made sense? Did you change anything else in the calibration?
There is a lot of timing difference between the one I sent and the _0016 calibration. To be honest the _0016 timing is very tame. That is set up for a stock L03 with swirl port iron heads.
Do you have a method of verifying fuel pressure while under load. Not sure how many VE learns have been done. But if the VE tables aren't falling into shape that usually points to a fuel delivery issue.
As the fuel pressure changes so does the BLM, which causes the learn to be way off. Try a VE Learn and check that things are falling into place. One other thing, is the NB O2 sensor heated? I believe that there are headers on the engine, if so you need a heated O2 sensor.
RBob.
There is a lot of timing difference between the one I sent and the _0016 calibration. To be honest the _0016 timing is very tame. That is set up for a stock L03 with swirl port iron heads.
Do you have a method of verifying fuel pressure while under load. Not sure how many VE learns have been done. But if the VE tables aren't falling into shape that usually points to a fuel delivery issue.
As the fuel pressure changes so does the BLM, which causes the learn to be way off. Try a VE Learn and check that things are falling into place. One other thing, is the NB O2 sensor heated? I believe that there are headers on the engine, if so you need a heated O2 sensor.
RBob.
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Re: Starting to tune my 305TBI
Its a heated O2 sensor.
Ill check base timing tomorrow if I can [I dont have a timing light]
All I did was change the idle, and it dident really change the idle.... I added 200 to all the values in park/neutral and drive, but the car still idles at the same rpms it always has, which I find odd.
I took a little bit off the SA tables and it seems to be running better now, but I couldent drive long because I guess I spilt too much oil and my car was getting all smokey inside [I had just changed my oil]
Ill check base timing tomorrow if I can [I dont have a timing light]
All I did was change the idle, and it dident really change the idle.... I added 200 to all the values in park/neutral and drive, but the car still idles at the same rpms it always has, which I find odd.
I took a little bit off the SA tables and it seems to be running better now, but I couldent drive long because I guess I spilt too much oil and my car was getting all smokey inside [I had just changed my oil]
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Re: Starting to tune my 305TBI
Yes. Check/Set the timing with the engine warm and the BYPASS connector open (sometimes called the EST connector). For that engine I would use 6* BTDC as the base timing. Then set the same value in the BIN.
A timing light isn't expensive. Should have that and a fuel pressure gauge. For a light get the basic model, no dial back or anything fancy. Just be sure it has a strobe light bulb (xenon), not one with a neon light in it.
With the change in commanded idle RPM, did the ECM open the IAC further? Maybe the IAC is bad or the IAC steps are already max'd out.
If the IAC is already max'd then open the throttle blades some. Should idle at the commanded RPM with between 5 and 10 steps.
As the tune gets better you will probably need to adjust the throttle blades. Most likely the IAC will go to zero and the idle will increase. Just close the blades down if/when this happens.
RBob.
A timing light isn't expensive. Should have that and a fuel pressure gauge. For a light get the basic model, no dial back or anything fancy. Just be sure it has a strobe light bulb (xenon), not one with a neon light in it.
With the change in commanded idle RPM, did the ECM open the IAC further? Maybe the IAC is bad or the IAC steps are already max'd out.
If the IAC is already max'd then open the throttle blades some. Should idle at the commanded RPM with between 5 and 10 steps.
As the tune gets better you will probably need to adjust the throttle blades. Most likely the IAC will go to zero and the idle will increase. Just close the blades down if/when this happens.
RBob.
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Re: Starting to tune my 305TBI
Isent 6* what its set from the factory?
The current value is 0*, so thats off for sure.
The IAC might be bad, I cleaned it out because it was causing my engine to die as soon as it was started before. But its pretty old, so I might replace it.
Im debating whether I should add my supercharger yet [im trying to get the tune a little closer], would that run fine? Or would it seriously throw off my tune?
The current value is 0*, so thats off for sure.
The IAC might be bad, I cleaned it out because it was causing my engine to die as soon as it was started before. But its pretty old, so I might replace it.
Im debating whether I should add my supercharger yet [im trying to get the tune a little closer], would that run fine? Or would it seriously throw off my tune?
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Re: Starting to tune my 305TBI
LO3 base timing is 0* (factory stock). The reason for 6* BTDC is that the engine is modified. The base timing mostly affects cranking to start. With the cam the engine will like additional timing during cranking.
Note that both the distributor base & calibration initial values both need to match.
With a stock timing tab the first wide valley is 0* (at the notch in the valley). The next valley towards the passenger side is 6* BTDC. This is where the damper line should be. Get a timing light and check/set it. Then set the calibration value and flash it in.
Idle & IAC: take a look at a recent data log (last nights?) and check the IAC steps while the engine is trying to idle. Need to get used to using log files to see what the engine is doing.
As for the supercharger, I wouldn't even consider it until the current tune is squared away.
Speaking of which, what MAP sensor is currently installed? If a 2-bar has the 2-bar MAP option switch been set?
RBob.
Note that both the distributor base & calibration initial values both need to match.
With a stock timing tab the first wide valley is 0* (at the notch in the valley). The next valley towards the passenger side is 6* BTDC. This is where the damper line should be. Get a timing light and check/set it. Then set the calibration value and flash it in.
Idle & IAC: take a look at a recent data log (last nights?) and check the IAC steps while the engine is trying to idle. Need to get used to using log files to see what the engine is doing.
As for the supercharger, I wouldn't even consider it until the current tune is squared away.
Speaking of which, what MAP sensor is currently installed? If a 2-bar has the 2-bar MAP option switch been set?
RBob.
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Re: Starting to tune my 305TBI
Ill check out the datalogs. Ill take some more today as I played with the tune a little bit, maybe I could email it all to you tonight and you could take a look at it? Tell me what areas need to be adjusted.
The MAP sensor is stock, not sure what they used in 1992? Where is the MAP sensor located, I dont think ive even seen it before.
And thanks for all the help
The MAP sensor is stock, not sure what they used in 1992? Where is the MAP sensor located, I dont think ive even seen it before.
And thanks for all the help
Last edited by Timothayyy; 12-18-2008 at 12:46 PM.
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Re: Starting to tune my 305TBI
MAP is mounted on the cowl under the hood. Small black plastic box with a 3-wire connector and vacuum line out of the bottom. Toward the passenger side of the rear fo the engine. Vacuum line (pressure line?) goes to the port of the center back of the TBI unit.
Email one of the most recent data logs. I'll take a look at it.
RBob.
Email one of the most recent data logs. I'll take a look at it.
RBob.
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Re: Starting to tune my 305TBI
My car is having major issues, like a crazy coolant leak that spews steam into the cab. It was also having major hesitation, my timing was off a bit and i set it at 6degrees advanced, its running like crap today though.
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