Remote Tuning

[VINCE]

I realize the throttle screw is for the IAC positioning, but I assumed all things being equal an engine with a larger cam will need more throttle opening, which means a higher IAC count, which I'm trying to reduce. It's about 20%+ in gear - is that OK? I can't do 2% in gear, or I won't have control of the idle out of gear, as the percent will drop to 0.

Is there way to test injectors at home for proper operation? I'm going to get a temp guns and make sure each cylinder is running at idle, which I think it is, but who knows.

[Danny Cabral]

I can't do 2% in gear, or I won't have control of the idle out of gear, as the percent will drop to 0.

I never mentioned an IAC Position of 2% in gear. Set the IAC Position at hot idle, with the transmission in neutral.

Is there way to test injectors at home for proper operation? I'm going to get a temp guns and make sure each cylinder is running at idle, which I think it is, but who knows.

If you just want to know if the fuel injectors are operating: You can use an injector noid light (Link), an injector probe (Link), or even a long screwdriver used as a stethoscope (placed between an injector and your ear, listening to each working injector). Other less definitive methods for MPFI applications, include infrared temp gun readings on header primary pipes, or a wet rag on header primary pipes.

[VINCE]

I never mentioned an IAC Position of 2% in gear. Set the IAC Position at hot idle, with the transmission in neutral.


If you just want to know if the fuel injectors are operating: You can use an injector noid light (Link), an injector probe (Link), or even a long screwdriver used as a stethoscope (placed between an injector and your ear, listening to each working injector). Other less definitive methods for MPFI applications, include infrared temp gun readings on header primary pipes, or a wet rag on header primary pipes.

OK Dan, the IAC in gear is around 5% or less hot.

I'd like to rule-out all the little stuff before I get a professional involved. I changed plugs, coils, ruled-out the IAC (I think). I'd like to try another set of wires too at some point, although these are new MSD's. My temp gun shows heat in each exhaust port. I unplugged each coil pack as the engine was running, and each cylinder dropped out.

So just to describe the issue again: A surging idle up & down. I also noticed yesterday that if I hold the throttle steady at even 2000 RPM, the surging/oscillation is also there! Things I've done and no change: disconnected IAC, played with AFR & timing. Turned off/on Closed Loop/Learn, P-Spark. I smoothed out the Base Fuel Table. I was wondering about a vacuum leak, but I don't think a vacuum leak would cause a surge right? It would be just a higher idle speed, I would think. I would also like to get the injectors tested - maybe one is working only partially, but again all cylinders seem to be hitting at least at idle.

Is there any other things I could try within the software - like injector end angle or something else?

[Danny Cabral]

OK Dan, the IAC in gear is around 5% or less hot.

Again, set the IAC Position at hot idle, with the transmission in neutral (not in gear).

So just to describe the issue again: A surging idle up & down. I also noticed yesterday that if I hold the throttle steady at even 2000 RPM, the surging/oscillation is also there! Things I've done and no change: disconnected IAC, played with AFR & timing. Turned off/on Closed Loop/Learn, P-Spark. I smoothed out the Base Fuel Table.

I'd have to review a datalog (& Global Folder) of this surging. But I reserve this effort as a last resort. Otherwise I'd be bombarded with Global Folders/Datalogs from many people. So I agree with seeking the help of a professional.

[VINCE]

Sorry Dan, I meant 3-5% in neutral! Thanks for your help.

[Danny Cabral]

So just to describe the issue again: A surging idle up & down.

Since the IAC Position % is properly adjusted, I'd be looking at the Base Fuel Table, Base Timing Table & Target A/F Ratio Table. You'll have to look at the Learn Table too, since it functions together as one with the Base Fuel Fuel Table (Link). Look at where the live cursor is moving during this idle surging. See if the AFR or timing changes a lot during this surging. Determine if it's surging due to an oscillating rich/lean condition. Ensure the Target A/F Ratio Table and Base Timing Table are flat in the idle area. Also, since this is a forced induction application, you probably lost some MAP kPa resolution in the idle area. You may need to reconfigure the MAP kPa axis (scale) for a little more resolution in the idle area. Then ensure the Fuel Graph is smooth in the idle area.

[The Dickens]

Team Viewer. Much better than Log Me In.

I don't do remote as much as I did before, so I have not been looking very hard. Thanks for the tip. I'll give it a try this week.

[VINCE]

Now that I've been researching this Injector End Angle a bit, let me ask another question. I understand that Injector End Angle is when the injector ends its spraying of fuel, but WHEN does the injector START injecting; at TDC? Just curious. And, if you set the Injector End Angle to -180 like I did, it means the injector ends its injection cycle at TDC correct? So is the injection & ending at TDC?

The more answers I get, makes me want to ask more questions. LOL!

[Danny Cabral]

I understand that Injector End Angle is when the injector ends its spraying of fuel, but WHEN does the injector START injecting; at TDC?

Sequential & Untimed Sequential fires each injector every 90° (crankshaft degrees). The fuel injector pulse width begins the event, but the crank angle it starts opening is based on IPW & RPM. Injector pulse width is "time" (duration), and the injector end angle is an "angular" calculation. In the "Help" Contents of the V4 EFI software, read the "Injector Phasing Instructions" document, and see Figure 1: "Cam Intake Centerline Method".
http://www.motec.com.au/forum/viewto...p?p=3583#p3583 (Good technical description from Motec. Read first paragraph for details.)

[VINCE]

Dan, would changing the Injector End Angle alter the fuel delivery in terms of base fuel/CL correction? My car is using a lot of fuel lately in terms of IDC & lbs/hr, and wonder if changing the Injector End Angle to -180 had anything to do with it. Or maybe that cold air is helping the engine make more power, LOL!