Idling on Megasquirt

[AngryMcMuffin]

Hey all, been a long time. But I finally got my AFR headed, Trickflow Stage 1 cam, and GT40 intake top end car to start and idle for a little bit on a Megasquirt PNP for a Foxbody from DIYAutotune.

Ultimately, this was easy. And embarrassingly it took a few years due to lack of motivation after I couldn't figure out the fuel rail quick disconnect.

The MS2 means I'm still speed density, just good and tuneable speed density.

I think this is the appropriate place for a tuning thread, if not, someone please correct me.
If so, I'll update this as I get it the rest of the way on the road and upload a video when I figure that out.

[AngryMcMuffin]

Video was too big, so I had to upload it to youtube. This is open headers with no o2 sensors installed yet. I've still gotta wire up my wideband, set ignition timing correctly, and button up several other things.

[AngryMcMuffin]

Made some more progress with this. Timing is still not set properly, and I destroyed my new TPS trying to modify it in a way to work with the Explorer throttle body. So, I'm going to use a TPS from a 1996 Explorer and the pigtail from the 1987 Grand Marquis, this is especially okay as the calibration is in Tunerstudio.

I did screw with the timing enough to make it start semi-consistently. It appears my sensors all register when plugged in. IAC is working, though I haven't been able to adjust the settings for it yet in tunerstudio, as I'm still hunting some vacuum leaks at the moment, so 'idle' is consistently at about 100kpa, which is atmosphere.

Hoping that I will indeed be able to use Speed Density to tune, instead of AlphaN. As I'm not familiar with how AlphaN calculate load values.

There should be more updates to this thread over the weekend, if all goes well.

[AngryMcMuffin]

So, I found that my issue is that my Explorer throttle body, bored out GM EGR spacer and intake are not sealing together. This is the cause of my 100kpa 'idle'. So, I guess I'll have to tackle that while I'm wiring in my electric fan and such today.

[Tiggie]

I know nothing about tuning but I am reading your posts. I have a feeling I may need to delve into this field at some point in the future, so I am trying to learn as much as I can.

[sly]

yeah... if all that stuff doesn't seal together well, it will idle rather high.

[gadget73]

You need a Lightning EGR spacer to use with the Explorer throttle body. Can't bore the stock piece out enough to seal with a 60mm unit. It will do a 60mm HO one with no fuss.

Specific possible issue, some of them have a groove around the center bore that goes to the outside for an unknown purpose. its on the side that water is on. I've had to shave the face of the spacers down to eliminate that because a 60mm hole through the middle of the EGR spacer gets into that groove and you get about half the gasket surface which is already reduced thanks to being bored out.

Alpha N doesn't calculate much of anything. Its a stupid simple lookup table that is basically throttle position and RPM to look up a fuel value. Works fantastic for things that only need to idle or go wide open on a flat track but its kinda shitty for anything that might need to work in variable load conditions.

[AngryMcMuffin]

You need a Lightning EGR spacer to use with the Explorer throttle body. Can't bore the stock piece out enough to seal with a 60mm unit. It will do a 60mm HO one with no fuss.

Specific possible issue, some of them have a groove around the center bore that goes to the outside for an unknown purpose. its on the side that water is on. I've had to shave the face of the spacers down to eliminate that because a 60mm hole through the middle of the EGR spacer gets into that groove and you get about half the gasket surface which is already reduced thanks to being bored out.

Alpha N doesn't calculate much of anything. Its a stupid simple lookup table that is basically throttle position and RPM to look up a fuel value. Works fantastic for things that only need to idle or go wide open on a flat track but its kinda shitty for anything that might need to work in variable load conditions.

Glad to see you and Sly commenting on this thread, if I recall, you all have a lot of time spent on this chassis and drivetrain modifications.

I'll link another Youtube video of idle and a couple revs on closed loop idle.
I finally got my basemap happy enough to where only hot starts are temperamental.
I've got to finish wiring the wideband o2 sensors and fan to the ECU.
Car maintains temp really well wit the Mark VII (if I recall, ordered it a few years ago) fan on the higher speed only, for now. And that's manually triggering it at 190 degrees Fahrenheit.
So, went through a few heat cycles at idle.

Alpha N did look very basic, and I imagine the drive-ability would suffer. Especially, if you even can, tune any of the more advanced acceleration enrichment strategies.

But my vacuum issue was multiple things, I'll go over them here: The TB and EGR spacer not sealing and the port I was using for vacuum reference on the upper intake manifold was pull no vacuum.

To resolve the TB sealing issue, I filled both sides of the EGR spacer with JB weld and sanded it flat. I have no need of use for EGR or coolant running through, causing my intake air temps to run hotter. Seals perfectly now. This is still not ideal as the EGR spacer is still not bored out to the size of the Explorer TB exactly, but it should work until I go to a 4150 carb style EFI intake and a 4bbl style throttle body. I know this will potentially give me less low end, but should make the engine bay a lot cleaner and serviceability of the engine in the bay better.

And to find a proper vacuum reference, I just made a trip to the parts store for some vacuum line and various sized fittings and made something work. Vacuum line routing will be cleaned up when the car moves under it's own power again.

My current TPS is garbage, and the throttle return spring is weak on the explorer TB. But that should be easily solved when my new TPS shows up.

I'll go more in depth on tuning adventures once I get wiring finished and the exhaust reconnected with o2 sensor bungs in the downpipes.

Going from the stock manifolds to ebay shorty headers with 2.5 collectors makes it a bit harder to just bolt it back together.
But the goal is to drive it home from the exhaust shop this coming weekend, hopefully.

Link to closed loop idle without vacuum leaks, this is 12 degrees BTDC base timing, matched to the MS2 and commanded 20 degrees BTDC at idle. Vacuum is around 30-40ish kpa at idle at 750ish RPM, so whatever that works out to in a standard measurement, seems fairly decent. Please ignore the belt squeal.

https://youtube.com/shorts/lwOHISU8OD0

I approached tuning idle the same as I would a carburetor idle, by ear and smell, obviously with some form of vacuum reference, so I went for whatever didn't immediately burn my eyes and had decent vacuum/RPM stability. I did borrow the base for my timing map from a Mustang forum post from someone with a full Trick Flow top end kit though. Obviously this will be refined further after I have all the proper sensors and such installed.
I did however, calibrate the IAC open/closed duty cycle, which is necessary for the return to idle. I'll upload some tune files, for other's reference once I get everything more put together.
Engine seems healthy to me and isn't making any weird sounds internally. I have like 2-3 hours of run time, total, so far.

[AngryMcMuffin]

As a note, the MS2 plugs in and works. You do have to remove some material from the fire wall to make it fit, this is due to the MAP sensor port that's built in, and the plug for the cable to connect to a laptop.both being on the same side as the EEC-IV connector. I used a Milwaukee bandfile to open the ends of the hole for the ECM up and accommodate this.I'm also using my stock GREY TFI module. I do not know if the black one works as well, as I have had no reason to try.

[sly]

Yeah, that sounds a lot better. 12 degrees base and 20 commanded sounds about right. I know the 88 MGM used to like 12-14 base as well and with the SPOUT jumper in, it would idle around 20-25 degrees. Sounds like you just need to finish hooking up everything at this point.

[AngryMcMuffin]

Yeah, that sounds a lot better. 12 degrees base and 20 commanded sounds about right. I know the 88 MGM used to like 12-14 base as well and with the SPOUT jumper in, it would idle around 20-25 degrees. Sounds like you just need to finish hooking up everything at this point.

Yeah, that's pretty much it right now.

I got the fan wired to the ECM and triggering from it now. That was a battle of me not understanding the "Hysteresis" parameter for the output trigger to ground my relay. Again, only the high speed right now, I have it coming on at 190 and shutting back off at 180, I'm running a 180 degree thermostat, and I'll wire in a relay to another output trigger for the low speed and use it for regular cooling just to reduce electrical load.

Tonight I plan to get the o2 sensors wired in, after that and adapting the TV cable, I should be able to get the exhaust reattached this weekend and possibly get into actually tuning and/or driving. Depending on how much the trans/rear gear hates me, as that's currently all stock.

[AngryMcMuffin]

This is startup at probably around 120 degrees coolant temps, so it does start and idle fairly consistently now.

I had read somewhere that spark cut for a limiter wouldn't work with stock TFI, as it turns out, whoever said that was wrong. As you can see a 2700 RPM spark cut limiter here. Please ignore the terrible sounds the belt is making, I hope to address that this evening as well.

There is plenty of info on the MS2 on how to change these settings, but I may dig into it later. I just feel it's not relevant to this thread yet.

[87gtVIC]

Nice work. Keep at it.

[AngryMcMuffin]

Nice work. Keep at it.

Thank you! And will do.

Today's update is that I got the throttle linkage swapped, finished wiring in my dual wideband, I have no bungs for the o2 sensors yet, but I verified that they read in Tunerstudio, and they read .1 lower, so we'll see how much fooling with calibrating that goes.

For some reason if I have cruise control hooked up on the linkage, it revs up and down constantly. Otherwise it holds a mostly steady idle.

After I unhooked the cruise control cable, I decided to put it in gear, I felt it go in, so with my foot on the brake I gave it a little gas.This resulted in accidentally launching a wheel dolly across the shop and spilling a full drain pan of oil that it hit.
However, that meant the car would move. So I ended up driving the quarter mile to my regular gas station and filled up.

Nothing broke and nothing caught on fire. So, that's a really good first drive if you ask me!

Next time it'll be with exhaust and o2 sensors in it so it can actually start being tuned.

I have to fix a coolant leak from the water pump side of the upper radiator hose. And I need to finalize my vacuum line routing so it actually includes the fuel pressure regulator.

Other than that, it ran great. I haven't driven a car with an automatic trans more than a handful of times since I took this car apart, so that was a very weird experience for me.

Is it appropriate to ask in this part of the forum if the trans just feels that bad in stock form, or if my top end swap has made it feel worse/like it won't shift right?
Granted, my fuel map could be so far off right now, and the FPR not being plugged in could make it feel worse.

Regardless, the engine felt very healthy at 90,023 original miles, hopefully as I use it and abuse it now it'll last pretty well with good maintenance.

[Alice87]

This is good stuff... I was looking into MS PNP several years ago. Good luck with your endeavors!