MicroSquirt.com read only forum (Jan.15,2018)

Hey guys. I just put my turbo kit on my car and had megasquirt running on it while it was stock for about 500 miles

95 Cobra, stock 302 longblock, intercooled DIY 60-1 turbo kit, innovate WB, 42lb injectors, MSnS-E using 024s9 I believe. This is a TFI car using an MSD6A for ignition. I am not using PWM idle control, the stock EEC is controlling idle. Using the Megatune 2.25 final release.

Here is the problem. I borrowed a tune from a fellow turbo stanger with a similar setup. It was idling at 10.5:1 on his tune, I leaned it out by almost 50% and it's still idling at 12-12.5:1. It seems like I can lean out the VE table while it's running and get it to where it should be at about 14-15:1. But if I shut the car off and re-start it, it goes back to where it was. And yes I have re-burned the tune on there beforehand and re-checked parameters when I start it back up and it's where it should be after I changed it. I don't understand why I can't get it any leaner than that. It seems okay everywhere else, albeit a bit rich. WOT at 5lbs of boost is about 11-11.2:1 and part throttle is about 13:1....

Other mentionables - I have the stock EEC controlling the fuel pump, and have adjusted the allen screw on the throttle body all the way down, if I bring it up anymore the idle speed goes way up and it gets richer...I also still have the IAC plugged up.

Another question - how do I get megatune to read AFR in 14.7:1 instead of volts?

Forgot to mention it idles right now around 1000-1100 rpms real smooth...

Here is my tune

These are my answers, I threw a couple of questions of my own in there just for grins.

1. You have your spark table messed up, I don't think you need 36degrees of spark advance at idle. If you like it like that I'm not sure why, I would think the engine would start to miss around 30degrees. Compare the reading on your Timing light and balancer to what your Megasquirt advance says, adjust the trigger angle to make them match.

2. You have the stock EEC controlling the idle?

3. Your VE at idle is way too lean, richen it up, if the engine speeds up, you are doing the right thing, you should control the amount of air going into the motor to adjust the idle, not lean it out to slow the motor down.

If you can't slow the motor down by closing the throttle blade, and you have the Idle valve plugged, you must have a vacuum leak somewhere. lean out the idle a little, and get out the WD40 or carb cleaner, spray it around the intake, if the engine speeds up you found a leak.

4. The stock computer wants 1v TPS at idle, if you go lower you get an unstable idle, same if you go higher, the EEC thinks you have your foot on the throttle and doesn't care about it anymore. You need to adjust the throttle plates closed the recommended way, adjust the TPS for 1Volt and go from there or hook up the Megasquirt PWM fidle. It's just a $1.50 part and three wires with one more wire to the ECU plug, switch to LED17 for Ignition and your good.

5. Why is your handle cuda6pak again? (You have a Mustang!)

6. You can renumber the guages in the MSnS-extra.ini to give you the "afrguage" that you can replace another guage with.

7. If you have a wide band, why not turn on the AFR table?

MegaScott wrote:These are my answers, I threw a couple of questions of my own in there just for grins.

1. You have your spark table messed up, I don't think you need 36degrees of spark advance at idle. If you like it like that I'm not sure why, I would think the engine would start to miss around 30degrees. Compare the reading on your Timing light and balancer to what your Megasquirt advance says, adjust the trigger angle to make them match.

2. You have the stock EEC controlling the idle?

3. Your VE at idle is way too lean, richen it up, if the engine speeds up, you are doing the right thing, you should control the amount of air going into the motor to adjust the idle, not lean it out to slow the motor down.

If you can't slow the motor down by closing the throttle blade, and you have the Idle valve plugged, you must have a vacuum leak somewhere. lean out the idle a little, and get out the WD40 or carb cleaner, spray it around the intake, if the engine speeds up you found a leak.

4. The stock computer wants 1v TPS at idle, if you go lower you get an unstable idle, same if you go higher, the EEC thinks you have your foot on the throttle and doesn't care about it anymore. You need to adjust the throttle plates closed the recommended way, adjust the TPS for 1Volt and go from there or hook up the Megasquirt PWM fidle. It's just a $1.50 part and three wires with one more wire to the ECU plug, switch to LED17 for Ignition and your good.

5. Why is your handle cuda6pak again? (You have a Mustang!)

6. You can renumber the guages in the MSnS-extra.ini to give you the "afrguage" that you can replace another guage with.

7. If you have a wide band, why not turn on the AFR table?

1. I haven't really messed with the spark table much but it runs smooth everywhere the way it is now. I will try and mess with that sometime.

2. Yes I have the stock EEC controlling the idle per as we discussed in my other thread. I didn't want to build the extra thing for the pwm idle control so we hooked it up like this to have the stock EEC control idle. Remember my MS is piggybacked on the stock computer.

3. I adjusted the VE table real lean at idle to get the AFR down to 12.5:1. With them stock the way they were from the tune in the 30-40 range it was idling at about 10.5:1 and the engine speeded up. When I backed off that allen screw on the throttle body underneat the rubber plug, the RPM's go way up and it gets even richer. Do I need to adjust the actual place where the throttle cable hits/stops? There is no way to adjust the little stud coming out, there is nothing to grab onto to twist it or anything. Maybe I just didn't look hard enough...

I checked for a vacuum leak with starting fluid everywhere around vacuum lines and the intake and couldn't find anything. I am reading about 42kpa at idle right now.

4. I may have to look into the PWM idle.....where do I adjust the TPS volts at? All I did was calibrate it.

5. My first car was a 69 Barracuda 340! I'm a mopar muscle nut by heart!

6. I don't want to replace one of the main gagues with the AFR gauge, I just want to be able to type in AFR tables with 14.7:1 etc instead of volts

7. I haven't turned the AFR table on because I only know what I want at idle and WOT, and I don't want to enter it in volts.

Does your engine have a larger cam in it? 42KPA seems a little high. i was thinking the 5.0 with a stock cam should idle around 30kpa or less. Is your vacuum hose connected to the plenum?

As far as adjusting the TPS, I was talking about actually adjusting the TPS sensor to read 1V output at idle. The way it's normally done is disconnect the ISC, cose the throttle stop until you get about 600RPM, then plug thbe ISC back in, adjust the TPS for .8V to 1V. If the Stock computer is still running the idle too high there is a problem, maybe the stock ECU is not seeing the coolant temp properly?


As far as the idle and the AFR, Why not just set it like normal and accept it? I have a NB and I could care less what the idle AFR is, it idles like a rock, even with the A/C on.

By looking at your VE, if you have say 14.7-1 at 3000rpm and 40kpa, by the looks of it you have about 18-1 at idle. Wouldn't 12-1 at idle be richer?

6. I don't want to replace one of the main gagues with the AFR gauge, I just want to be able to type in AFR tables with 14.7:1 etc instead of volts.
7. I haven't turned the AFR table on because I only know what I want at idle and WOT, and I don't want to enter it in volts.

The above answers are counterdict each other, if you want to tune your VE using AFR instead of volts, you need to replace the EGO meter with the AFR meter for tuning page 1. If you want the EGO limits to follow a certain AFR you need to turn on the AFR target table, otherwise the EGO will always want to correct to NB specifications. I. E. Stoich = .5V

the stock EEC is controlling idle.

I have the stock EEC controlling the fuel pump

I am not sure exactly what your are saying here...

You mean it is controlling the idle valve?
So you must have a dual setup of CLT and MAT probes?
How does the "stock EEC" sense engine load (MAP) so that it can adjust the fuel pump?

I'm not sure why you would choose such a complex setup...

Please post a datalog.

Also...

It was idling at 10.5:1 on his tune, I leaned it out by almost 50% and it's still idling at 12-12.5:1.

Insensitivity to idle VE tuneing could mean your injector open time is set too large.

just to point it out, timing makes a HUGE difference on idle, both AFR and smoothness. I agree, that is way too much timing.

Jedrik wrote:

the stock EEC is controlling idle.

I have the stock EEC controlling the fuel pump

I am not sure exactly what your are saying here...

You mean it is controlling the idle valve?
So you must have a dual setup of CLT and MAT probes?
How does the "stock EEC" sense engine load (MAP) so that it can adjust the fuel pump?

I'm not sure why you would choose such a complex setup...

Please post a datalog.

Aha!

This may be where I'm having problems....I forgot to hook the stock Ford MAT back up after I put the turbo kit on!

I have duel CLT, one for the stock ECU and a GM one for the MS.




edit: But then come to think of it, I don't have the MAF hooked up either...

MegaScott wrote:Does your engine have a larger cam in it? 42KPA seems a little high. i was thinking the 5.0 with a stock cam should idle around 30kpa or less. Is your vacuum hose connected to the plenum?

As far as adjusting the TPS, I was talking about actually adjusting the TPS sensor to read 1V output at idle. The way it's normally done is disconnect the ISC, cose the throttle stop until you get about 600RPM, then plug thbe ISC back in, adjust the TPS for .8V to 1V. If the Stock computer is still running the idle too high there is a problem, maybe the stock ECU is not seeing the coolant temp properly?


As far as the idle and the AFR, Why not just set it like normal and accept it? I have a NB and I could care less what the idle AFR is, it idles like a rock, even with the A/C on.

By looking at your VE, if you have say 14.7-1 at 3000rpm and 40kpa, by the looks of it you have about 18-1 at idle. Wouldn't 12-1 at idle be richer?

6. I don't want to replace one of the main gagues with the AFR gauge, I just want to be able to type in AFR tables with 14.7:1 etc instead of volts.
7. I haven't turned the AFR table on because I only know what I want at idle and WOT, and I don't want to enter it in volts.

The above answers are counterdict each other, if you want to tune your VE using AFR instead of volts, you need to replace the EGO meter with the AFR meter for tuning page 1. If you want the EGO limits to follow a certain AFR you need to turn on the AFR target table, otherwise the EGO will always want to correct to NB specifications. I. E. Stoich = .5V

Stock cam, I thought the kpa was high too, when it was stock without the turbo kit it was around 30kpa at idle. I have checked for vacuum leaks everywhere and can't find anything. The guy I got the tune from on turbomustangs.com "Unatural" says his is at about 40kpa as well.

I only care about the AFR at idle because I'm scared of fouling the plugs, I just about did when I let it idle for a few minutes at 10.5:1. Changing the plugs on the passenger side would be a royal pain in the bum.

Thanks for the info, I see what you're saying about the AFR tables now. I'll try and figure out how to switch them tonight...