random stalling and idle swings

[printmanjackson]

Assuming you are running stock Vette fuel pressure (58 psi), the Red Top (Ford 30 lb'rs) injector values seem about 1 lb/hr too low across the board. Would pull about .3 out of the ms offset table from 11v to 18v across the board. Pull about .1 g/sec out of the short pulse adder across the board.

Ed,
what do you see that makes my injector values look low? I took the info from Greg's spreadsheet. I'm still using the stock fuel pump.

My TB is an LS2 90mm

I agree my AC offset is not even close, I just threw in something the other day playing around. It's cool around here now so I haven't had a need to use it.

[mowton]

Ed,
what do you see that makes my injector values look low? I took the info from Greg's spreadsheet. I'm still using the stock fuel pump.

My TB is an LS2 90mm

I agree my AC offset is not even close, I just threw in something the other day playing around. It's cool around here now so I haven't had a need to use it.

I'm at work, can't check but I see I missed the 90mm (thought I saw 102) and I'll recheck injectors tonight. Quess it was a bit early :-)

Ed M

[mowton]

Double check your injector data....you have the other "reds" data.

Ed M

[printmanjackson]

Double check your injector data....you have the other "reds" data.

Ed M

Ed, I don't know how you noticed this but the numbers do not match the spread sheet. Now, I got a strange question ..... what would keep the system from taking the correct data? I have tried copy and paste even tried typing the number directly and it won't take it. Do I have something flagged or am I going crazy?

example: the first box in the inj flow rate vs KPA VAC table calls for
0 kpa = 37.63189 from the spread sheet

37.63704 is in the box in the tune and I can not get it to take the correct number.

I can copy and paste the number on a word doc so I know it's coping the number correctly.

I don't know if it's rounding or what.

[mowton]

Ed, I don't know how you noticed this but the numbers do not match the spread sheet. Now, I got a strange question ..... what would keep the system from taking the correct data? I have tried copy and paste even tried typing the number directly and it won't take it. Do I have something flagged or am I going crazy?

example: the first box in the inj flow rate vs KPA VAC table calls for
0 kpa = 37.63189 from the spread sheet

37.63704 is in the box in the tune and I can not get it to take the correct number.

I can copy and paste the number on a word doc so I know it's coping the number correctly.

I don't know if it's rounding or what.

The 37.637 vs 37.631 is not the problem....That is rounding and is ok. If I understand which injectors you have, the 0 KpA value s/b 36.73. Your numbers are from the "skinny" injector types.

Ed M

[printmanjackson]

yes, they are the skinny part number M-9593-BB302

I thought I had put in the right numbers but I didn't remember looking that close. I thought I was loosing it when I couldn't change a number!

[LSxpwrdZ]

You can regain under/over spark correction if you raise the enable/disable mph of throttle cracker. I have to do this on some stalled auto car's where the stall acts like a rubberband with rpm. Spark really seems to calm things down a lot.

[printmanjackson]

You can regain under/over spark correction if you raise the enable/disable mph of throttle cracker. I have to do this on some stalled auto car's where the stall acts like a rubberband with rpm. Spark really seems to calm things down a lot.

I have the TC completely zeroed out now. TF is active till it hits idle. Mine is a stick and when you push the clutch in the TC will completely drop out. With the TF and TC dropping out with clutch in it leaves little to control idle drop. This is what I have been fighting. Timimg helps but at a point you get the rpm upswing that starts idle rolling.

[LSxpwrdZ]

With the table zero'd out it still won't deactivate the TC. I had to raise the speeds to get spark correction to enable while coating down. When the car reaches the disable speed set in the TC parameters the under/over spark correction should enable. If that doesn't work have you tried the rolling idle? Set the over speed integral in rolling idle parameters slightly lower so it doesn't pull so much airflow out when the clutch is pressed in. Some tweaking of the IAC Effective Area table will help also. I know it's ETC but calculations from airflow are still calculated off that table.

[edcmat-l1]

Some tweaking of the IAC Effective Area table will help also. I know it's ETC but calculations from airflow are still calculated off that table.

That's wrong. I've played with the IAC tables to no end. Even went so far as zeroing them out. They have no affect.

[printmanjackson]

I got it pretty close tonight.

I ended up putting the TC back in and then added some air to the Airflow Adder in the Rolling Idle table. This stopped the idle dropping past set idle and through testing different amounts of air it pretty much stopped the idle swings coming to a stop.

[printmanjackson]

I have been tweaking with the Airflow Adder in the Rolling Idle table and you can really fine tune this with a curve so as you are coasting down the road, clutch in, it has additional airflow to hold the idle at @ 1000 rpm then as you slow down start bringing the airflow down with the speed so when you stop it doesn't just drop.

[LSxpwrdZ]

That's wrong. I've played with the IAC tables to no end. Even went so far as zeroing them out. They have no affect.

Hadn't played with it enough to see that...

[printmanjackson]

Hadn't played with it enough to see that...

I know that feeling all to well

[turbo4.5]

i thought that the overspeed and underspeed were really high swings. i noticed with bigger cams +- 3 degrees seems to work better sometimes even less.

[edcmat-l1]

Hadn't played with it enough to see that...

I tune Vettes primarily. I can tell you more about the ETCs than anything else LOL. I have thousands of hours figuring them things out. I was the one that had the guys at HPT put the rolling idle tables in.

[LSxpwrdZ]

I do know that the rolling idle tables help ALOT.

[gn2beatu]

I have seen where some people can fix thier idle by drilling a small hole or two in the throttle blade if the IAC cant keep up. A way to see if this will help is to take out one of the screws in your throttle blade and leave it as an open hole. Start the car, IF IT GETS BETTER, drill a hole about the same size, but dont put the screw in yet. Now start the car with the new hole and the screw still out. This will simulate two holes. If it gets better, add a 2nd hole and put the screw back in. If it doesnt, put the screw back in and leave the one hole. Usualy one to two small holes will fix it and you can fine tune from there. Kinda like the old days when you had a carb, and you had to open the throttle blade and that closed off the idle passages, so people drilled holes in the blades.

Now if its the other way around and you need less air. You can take the black plastic cover off the ETC. You will see a black plastic cam that stops on the housing that acts like a throttle stop. If you wish to close your throttle blade some more, remove some of the material from the black plastic cam, and or aluminum. I have successfuly moved the throttle blade up to 1/4" more closed this way. Someone overported a throttle body, and I was able to close it just enough to get the idle back down. It was pulling major timing at idle, like -12 degrees. This is a way to see if your getting too much air, look at your timing, the car will try to pull a crap load of timing to get the idle down. Probably not whats going on for you, but something to check anyways. Hope that helps some if you want a more mechanical fix.

[edcmat-l1]

I have seen where some people can fix thier idle by drilling a small hole or two in the throttle blade if the IAC cant keep up. A way to see if this will help is to take out one of the screws in your throttle blade and leave it as an open hole. Start the car, IF IT GETS BETTER, drill a hole about the same size, but dont put the screw in yet. Now start the car with the new hole and the screw still out. This will simulate two holes. If it gets better, add a 2nd hole and put the screw back in. If it doesnt, put the screw back in and leave the one hole. Usualy one to two small holes will fix it and you can fine tune from there. Kinda like the old days when you had a carb, and you had to open the throttle blade and that closed off the idle passages, so people drilled holes in the blades.

Now if its the other way around and you need less air. You can take the black plastic cover off the ETC. You will see a black plastic cam that stops on the housing that acts like a throttle stop. If you wish to close your throttle blade some more, remove some of the material from the black plastic cam, and or aluminum. I have successfuly moved the throttle blade up to 1/4" more closed this way. Someone overported a throttle body, and I was able to close it just enough to get the idle back down. It was pulling major timing at idle, like -12 degrees. This is a way to see if your getting too much air, look at your timing, the car will try to pull a crap load of timing to get the idle down. Probably not whats going on for you, but something to check anyways. Hope that helps some if you want a more mechanical fix.

I think maybe you should just stop giving advice until you learn a little more.

[printmanjackson]

I think maybe you should just stop giving advice until you learn a little more.

ditto