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blkaplan
07-24-2005, 02:24 PM
hello,
my 88 msns 245+T gets really bad hot idle performance at the track, normally it idles smooth and no fluctuations, when it gets really hot it goes from 800~400~800........

I am not running any IAC or any idle enhancers, the car has A/C but it is not turned on

any suggestions?

The Aspirator
07-24-2005, 03:29 PM
How much vacuum is it pulling? You have the M or T-cam right? I'd say that your fuel table at idle is poor, probably too lean I would guess. Especailly with a T-cam you should be pulling at least 35kpa, if it's like 40+ then you're idle will be poopy. Got a wideband on that sucker? And what ignition advance are you idling at?

blkaplan
07-25-2005, 01:27 PM
i get 20" of hg at idle, im running a M cam, it is about 12 degrees @ idle.

i have a wideband it idles around ~13 afr

kyle242gt
07-25-2005, 01:29 PM
bump the timing up, see how that works. I also think you might be too rich; my car likes to idle at 15-16:1

blkaplan
07-25-2005, 02:07 PM
thats odd, my car idles really smoothly at 12.... the leaner i get the less smooth the idle is usually

benflynn
07-25-2005, 02:42 PM
let it idle rough and save gas

The Aspirator
07-25-2005, 06:36 PM
Your settings sound about right. My car likes 13.5 idle, but the weird thing is that my car pulls the most vacuum and idles the best with an idle advance of like 35*. I know, that's way more than anybody else is running (usually 12-18), but my car loves it. Weird. I pull 20" of vacuum too, with my K-cam.

the poi
07-25-2005, 10:27 PM
ya, i've had the best idle with some more advance, like around 15-17. 12 is "stock" but it only idles well at 12 if its pretty rich. you're probably killing baby seals and the ozone layer with more ignition timing, but eh

Hank Scorpio
07-29-2005, 11:36 AM
thats odd, my car idles really smoothly at 12.... the leaner i get the less smooth the idle is usually

My old 242 was the same way.

Matt Dupuis
07-29-2005, 03:16 PM
Ben, it's part of the IAT correction issue. Hopefully fellow Megasquirters are working on it, but what I've found to work best is to mount the IAT sensor right behind the front bumper. That way you get a decent amount of correction for the weather, but your under-hood heat doesn't mess with it and make it do what you're finding it does.


I've been fighting with this for two years. So far, this is the only thing I've tried that works. Changing the Airdenfactor.inc file works, to a degree, but it's still getting way too much correction at low RPM, where it needs almost none.

kyle242gt
07-29-2005, 03:29 PM
Matt, I've seen you mention this before, and I always wonder - what about IAT rise from boost?

I suppose if we were all lucky enough for an NPR or PSIC :roll: it wouldn't be an issue... but for stock IC, where temps can rise 20F easily enough over a boosted pull, isn't it more important?

blkaplan
08-24-2005, 10:41 AM
I am considering wiring in my lh2.2 idle control to my Megasquirt N Spark Extra.

From what I have read, I will need a resistor inline with the ground and wire my Fidle to control the valve and to activate led 17 output to trigger spark?

Does this sound correct?

For finding the output from L.E.D. 17 is it something that just requires me to solder a wire on to the output pins or do I need to solder something directly to the board and run the wire out of the case to get this output to work?

I am mainly interested in this to get my air conditioning running, the air conditioning should work but i have not turned it on since i megasquirted the car. Has anyone succesfully run air conditioning without having any idle enchancers?

Matt Dupuis
08-24-2005, 11:43 AM
Matt, I've seen you mention this before, and I always wonder - what about IAT rise from boost?

I suppose if we were all lucky enough for an NPR or PSIC :roll: it wouldn't be an issue... but for stock IC, where temps can rise 20F easily enough over a boosted pull, isn't it more important?

Sorry, Kyle - missed this when you first posted it.

IAT rise from boost is a fixed number, pretty much. The turbocharger efficiency and intercooler efficiency pretty much regulate the post-IC IAT, and since you set the VE and AFR in the VE table anyway, you might as well do the IAT correction in there as well. It's true that the intercooler exit temperature rises a little bit due to heat soak, but it's not a really big deal when you're only talking about 1-2% of fuel, IMHO.

Whatever over-fueling you end up doing during long high boost runs is WAY worth the extra driveability during hot starts, low speed cruise, etc. That's how I see it, anyway.

Boris has a lightning-quick thermocouple mounted right in his NPR outlet, which is really the best of all worlds - quick response, mounted in an area that doesn't see alot of engine compartment heat, reading pretty much actual intake temperature air. Probably what I'd suggest to be the best answer.

kyle242gt
08-24-2005, 12:24 PM
I am considering wiring in my lh2.2 idle control to my Megasquirt N Spark Extra.

From what I have read, I will need a resistor inline with the ground and wire my Fidle to control the valve and to activate led 17 output to trigger spark?

Does this sound correct?

For finding the output from L.E.D. 17 is it something that just requires me to solder a wire on to the output pins or do I need to solder something directly to the board and run the wire out of the case to get this output to work?

I am mainly interested in this to get my air conditioning running, the air conditioning should work but i have not turned it on since i megasquirted the car. Has anyone succesfully run air conditioning without having any idle enchancers?


I'm not sure about any of what I'm about to type :-D so maybe the best thing to do is ask on MSEFI; AFAIK nobody here has used the LEDs for outputs.

I figure you'd grab the LEDs ground pin and use it to ground a PN2222A or higher-rated transistor; see if you can find out what your idle valve (two wire, correct?) draws. There MAY be a PN2222A already in place for the LED, but then you have to wonder if it's up to controlling the LED and the idle valve. Not sure about the resistor, sorry.

My AC ran fine until it blew a line :grrr: without any AC-related idle increase. And I used a Kjet idle valve with some success. I didn't get the 1300RPM ice-cold idle I really want, but it worked okay. I really ought to put it back on. With nothing for idle control, hot idle is a silly 1000-1100 RPM :roll: and cold idle is dicey at best.

Matt - thanks for the reply; that's where my IAT is already, so mayhap I'm good to go. Is your deep-set IAT enmity from putting the IAT in the intake manifold?

blkaplan
08-24-2005, 01:36 PM
I thought someone or a few people on the board have successfully installed there IAC's using PWM through MegaSquirt N Spark Extra. Can anyone chime in? I can start a new thread but it is related to the topic of the thread so I figured it would be better to continue this.

wildmanben
08-24-2005, 01:40 PM
Your settings sound about right. My car likes 13.5 idle, but the weird thing is that my car pulls the most vacuum and idles the best with an idle advance of like 35*. I know, that's way more than anybody else is running (usually 12-18), but my car loves it. Weird.

You're not the only one that likes to idle at 35* ;-)

Matt Dupuis
08-24-2005, 02:16 PM
I thought someone or a few people on the board have successfully installed there IAC's using PWM through MegaSquirt N Spark Extra. Can anyone chime in? I can start a new thread but it is related to the topic of the thread so I figured it would be better to continue this.

I'm using the Ford IAC valve. To use that I followed the directions on the MSNS-Extra pages. I upgraded the transistor, etc., but I only use the valve for warmup idle control. I'm sure it would work fine for AC compensation..

Matt - thanks for the reply; that's where my IAT is already, so mayhap I'm good to go. Is your deep-set IAT enmity from putting the IAT in the intake manifold?

I tried the IAT sensor in the manifold, in the IC-TB pipe close to the engine, in the IC-TB pipe close to the IC, in the filter-turbo pipe, and behind the bumper.

With the IAT in the intake, it heat soaked the most and it took the longest to respond to changes, but the difference between totally heat soaked and normal running was not too bad.

With the IAT in the IC exit pipe close to the engine, it responded quicker to changes in temperature, but it still picked up a goodly amount of heat from the engine compartment. What's worse, the IC pipe temperature was quite a bit lower than the intake manifold temperature, so the IAT readings would actually fluctuate more than when the sensor was in the intake.

With the IAT in the IC exit close to the IC, it was better than when it was further back, but it still picked up lots of engine compartment (and radiator) heat.

With the IAT sensor right behind the filter, it was good under normal conditions, but it would still pick up lots of heat from the nearby radiator.

Having the IAT sensor right behind the front bumper, the car starts and idles perfectly when hot, cold, warm, heat soaked, etc. First time, every time.

Honestly, my views towards the IAT sensor is that it's given FAR too much influence over the fuel calculations, and it should actually affect the spark timing more than it should the fuel. Furthermore, the sensor should have very limited influence when the engine is under light load... right now it's got way too much control to be an effective tuning tool.

blkaplan
08-24-2005, 02:58 PM
I'm using the Ford IAC valve. To use that I followed the directions on the MSNS-Extra pages. I upgraded the transistor, etc., but I only use the valve for warmup idle control. I'm sure it would work fine for AC compensation..



So you configured LED 17 to control spark? If so does LED 17 have a pinout on the rb-37 connector? How did you make the physical connection, did you leave the LED on?

Matt Dupuis
08-24-2005, 03:40 PM
So you configured LED 17 to control spark? If so does LED 17 have a pinout on the rb-37 connector? How did you make the physical connection, did you leave the LED on?

LOL, to be honest, Ben - i can't really remember what I did.

OH YEAH, that's right. I used LED 17 as spark for the EDIS. I added a pullup resistor and strung a wire to somewhere on my DB-37 to provide info to the EDIS module. EDIS-4 originally used the fidle to control spark, but when I went EDIS-8 I needed to switch it to LED 17, so I made use of fidle to control the PWM IAC valve. Yes, the LED stays in place.

At the same time I added fan control and tach output to my Megasquirt, so basically I'm getting confused between the four mods done at the same time.

Hank Scorpio
08-24-2005, 03:41 PM
You're not the only one that likes to idle at 35* ;-)

I let my 21FT idle closer to 45* :rofl: thats how it liked it!

blkaplan
08-24-2005, 04:09 PM
OH YEAH, that's right. I used LED 17 as spark for the EDIS. I added a pullup resistor and strung a wire to somewhere on my DB-37 to provide info to the EDIS module. EDIS-4 originally used the fidle to control spark, but when I went EDIS-8 I needed to switch it to LED 17, so I made use of fidle to control the PWM IAC valve. Yes, the LED stays in place.

At the same time I added fan control and tach output to my Megasquirt, so basically I'm getting confused between the four mods done at the same time.

This is what I am attempting to do. What do you mean by "strung a wire." Do you have pictures of these?
I basically understands what needs to be done, I am just looking for some physical wiring examples of good ways to get extra outputs out of the megasquirt box.

Matt Dupuis
08-24-2005, 05:49 PM
I mean I soldered a wire from the LED to the DB-37. I'll try and get pix tonight.

blkaplan
08-24-2005, 08:01 PM
Thanks, a good picture is worth 1000 posts. ;-)

The Aspirator
08-24-2005, 11:55 PM
Wildmanben and Doug, good to know my car isn't the only one that likes a super high idle advance!

Ben, on my brothers MSnS I soldered a wire directly to one of the legs of LED17 (I think it was the negative leg) and ran that wire straight out to the ignition module. Not ideal or clean, but works great. Also you could string it inside the case, to one of the extra empty pins on the DB37 connector, if you look closely at the board around there there will be a few empty holes with little tracks that go towards the connector, use a DMM to figure out which one goes where. There's at least 5 extra pins, if not 10.

swedefiend
08-25-2005, 01:22 AM
There's at least 5 extra pins, if not 10.

Well, you were right about five. But not ten...

And I have been using led17 for spark output since day one (sometime in January for me). I am one of the few AFAIK (and it has been a source of confusion for many seeking my help since then as well). I have always had an idle valve on pin30. However, I just got around to adding the PWM function and am still sorting it out.

The Bosch two wire valve (PN: 0280140516) is an 8 ohm valve that operates between ~30%DC and ~60% - (still sorting that part out) and runs at 99.66 Hertz. AFAIK, 100 HZ will work good, but some of the MSEFI guys are fiddling around with the frequency to make the motor more quiet (I haven't really noticed mine being loud yet).

Anywho, I still am in the dark on the settings for this thing. I should have them figured out sometime next week. Wehn I get it nailed down, I will share the results here (unless someone else beats me to it)

swedefiend
08-25-2005, 02:52 AM
Yes, the LED stays in place.

Just thought I would add that this doesn't really matter. First, I installed the LED (because at the time, there was no other way to test on the stim - had to build it "OE" and then mod it) and then I cut the ground leg off and soldered to it. Then, when I redid the board about three months ago (added about all of the outputs I could - x3, x4, table switching ground, jumpered the MAP signal out, etc) I desoldered the leg even and just soldered the 16 gauge wire straight to the board.

No problems here...

blkaplan
08-25-2005, 06:57 AM
Wouldn't you want to solder your lead to the positive leg of the LED? This would cause them to wired in parallel and ensure there is equal voltage to each, I would think that if you had them wired in series you would have some type of voltage drop from the LED? If the IAC could except up to 12V you would not be able to supply that much.

swedefiend
08-25-2005, 07:49 AM
Wouldn't you want to solder your lead to the positive leg of the LED?

If you want to keep your fast idle solenoid control, you can choose to take the spark output from LED17 instead. If you do this you will need to run a wire from the (-) lead of LED17 to X11 for example, your spark output will then be on pin 25 of the DB37.

You also have to upgrade Q5 and R16 to drive the valve directly

blkaplan
08-28-2005, 11:06 PM
pics?

Captain Bondo
08-28-2005, 11:13 PM
I still think the high idle advance was representative of some sort of burn issue at least with John's car... but who knows. All I know is that has to be hard on the coil.

Anyways does MS have coolant temp correction maps? Seems like you could just fatten it up and advance the timing a little cold and not worry about an IAC? I know "." much about MS though of course. :-D

Matt Dupuis
08-28-2005, 11:59 PM
Sorry, Ben - busy few days.

The Aspirator
08-29-2005, 05:22 AM
Kenny, MS has always had warmup enrichments. Not really a map, more like "at 130* give it 10% more fuel", there's about 10 bins to tune. Also now there is something about changing timing when cold, apparently works great. When I get that B23 plopped in we'll see if the previously high idle advance #'s were cause of the squashed rods.

blkaplan
08-29-2005, 09:10 AM
A little update: played with the idle yesterday, I tried to advance timing upto around 30 like you guys were saying and it ran like crap, i put it back to 15 and it runs better but not great,

the problems I am having with the idle is my AFR is not constant, it will go from 12.5 to 13.8 and keep cycling...

the idle is right around 800 rpm right now once it gets hot...

When my MSnS used to have a rock solid idle and maintain one AFR the entire time? What do you think would cause something like this?

benflynn
08-29-2005, 11:35 AM
are we overlooking a low rpm miss...i know that the lm1 will pick up the extra o2 for a missed ignition event..

blkaplan
08-29-2005, 12:55 PM
i think this might be the issue?

what is the best way to go about diagnosing this?

what causes a miss?

what are the fixes?

kyle242gt
08-29-2005, 01:03 PM
Watch for RPM spikes in MTune, that can indicate noise in the dist signal line. Other than that, ole skool stuff, cap rotor plugs wires coil; check all connections for corrosion, etc...

What's your TA and idle timing? It could be that the rotor is pointing far enough out at idle to misfire.

I think it's too rich, but I seem to be in the minority. Aim for stoich, 20BTDC, and 1000RPM. See if that helps.

blkaplan
08-29-2005, 01:17 PM
How do I AIM for 1000 rpm? I cant figure out how to adjust my idle speed? I tried messing with the knob on the throttle body but it doesn't seem to have any effect?

The car is originally a 88 245 dl with lh 2.2.

I think my trigger angle is 60, I will check when I get home.

kyle242gt
08-29-2005, 01:28 PM
My throttle screw doesn't do anything either :e-shrug: probably because I don't have an IAC which surely must flow some air at all times (the old Kjet valve sure did).

If you can't get the idle up with the screw, just adjust it with the throttle cable. A TA of 60 sounds like what a lot of guys run, so that should be okay; although I'd wonder if you're getting some weirdness from it interfering with high (50+) advance. That was a problem with some code versions, but it may have been straightened out. My TA is 134, but I'm a screwy-louis.

benflynn
08-29-2005, 01:53 PM
The Idle Screw(blk Knob) Will Work If The Passage Is Clean..it Just Pulls Air Through A Hole In Front Of The Butterfly, And Exits Just Behind It, Mine Works A Little But Is Partly Clogged, MY TA IS 15 AND SEMS TO WORK FINE AND IT LINES UP WITH LIGHT

blkaplan
08-29-2005, 01:55 PM
i verified last night that my idle timing was accurate and it seemed to be....

Matt Dupuis
08-29-2005, 07:57 PM
pics?

Hope you're not expecting much...

http://members.shaw.ca/UglyDuck1/junk/100_2070.jpg

^^ shows the pullup resistor on the LED-17 ^^

http://members.shaw.ca/UglyDuck1/junk/100_2071.jpg

^^ Black wire = wire from LED-17 to DB-37 ^^

http://members.shaw.ca/UglyDuck1/junk/100_2074.jpg

^^ Haxxored Megasquirt 1.01. Includes flyback board, fast idle mod, EDIS mod, MS tach output mod, and fan control mod. ^^

blkaplan
08-29-2005, 09:15 PM
what does the flyback board do?

Captain Bondo
08-29-2005, 09:32 PM
To set idle correctly, screw the black knob on the TB all the way in. Then use the threaded throttle stop adjuster- it has an 8mm lock nut and has a slot in the end for a flatblade. That is the "base idle" adjustment. Adjust it so the idle is about 750rpm. Lock the nut down and then screw out the black knob until yuou get about 950 +/- 50rpm. You may need to readjust the tps depending on how far out of wack the throttle stop was.

John, sounds good on the cold enrichment maps- my theory is if you enriched it a bit and also used a cold timing advance you'd basically get a fast, rich idle cold thanks to the extra advance.

blkaplan
08-30-2005, 12:56 AM
thanks for the heads up kenny, I will give that a shot...

now if i could just get rid of that damn chassis flex ;-)

Matt Dupuis
08-30-2005, 05:34 AM
what does the flyback board do?

Lets you run low-z injectors (like Volvo Turbo injectors) without resistors. Basically it uses a high current to slam the injectors open quicker than when used with resistors, and keeps a minimal current through them to just barely hold the injectors open, which takes less time to break down and lets them close quicker. Simplifies installation and improves useable injector duty cycle, with the addition of some (slight) additional tuning.

blkaplan
10-11-2005, 04:39 PM
just an update for others peoples help.

I had never adjusted the idle range from when i changed the car over from auto to manual.

That with the combination of disconnecting the IAC resulted in an idle setting that was too low.

After adjusting the idle stop bolt ( thanks for the suggestion Kenny )

it idles much more stable.

Cheers