3.0L Megasquirt w/ EDIS: Headers running at different temps?

[jangell]

You still have IAC open 40 steps at full warm so you can further close the IAC valve. You could also enable closed loop idle control and just specific the RPM you want and see if it works off the bat.

Cool, thanks. I'll give them a try once I've added fuel and tried to get the AFR down.

DMC manual specifies the advance by degrees somewhere near the ignition section (?) The Volvo ignition greenbook TP31397-1 has the curve for the OEM distributor (and a few other B27x and B28x motors) but is too old for your engine. Since the 3.0 was totally ECU controlled there is really no reason to have published the curves like this as a mechanic wasn't going to do anything useful with the data. To obtain the original spark map you would have to reverse engineer it from the OEM ECU or measure it somehow. Maybe you could find that data outside of the DMC world.

Thanks. That fits with the "this is set at the factory" bits I was seeing in the Monaco/Premier manuals.

Either will work, but from what I've read TPS is preferred. It will be a better gauge of your intention. Otherwise the ECU has to watch for changes in MAP which will lag your actual foot.

That makes sense. I know you can use a combination of MAP and TPS, too. I'll read yup on this once I start playing with acceleration enrichment.

I had a fun problem where I accidentally hosed the firmware which caused the injectors to lock open w/ fuel pump running. First time I've ever had to siphon an intake manifold. The response was basically, "meh, first time this has ever been reported. You're more expendable than the time it would take to fix"

Yeah, that's pretty impressively bad. I'm a software developer, so I kinda get where they're coming from (extremely rare case that has never been reported in two decades or so), but I don't work on stuff that can get people killed if something goes wrong. You'd think they might just add a maximum injector open time to avoid the risk of that kind of problem.

That would be fun, especially fast charge becomes a reality. With a gas engine we can emphasize its "touring sports car" qualities but that's difficult to claim if you have to make long stops to recharge every few hours

Range is a big limitation. I would want at least 250 miles out of an electric car (which is about how far I could go on the 2.8L engine). It seems most electric conversions are under 100 miles -- enough to tool around town and get to/from work, but not enough to, visit my parents on the other side of the next state. I feel like you could pretty well pack the engine bay with lithium ion batteries if you didn't mind basically taking apart a Tesla battery sled and relocating the cells yourself. I guess you'd have to redo it every decade or so, but hopefully we'll get better battery tech at some point and you'll need fewer batteries, or get greater range.

I also do wonder about how a DIY conversion would connect to a fast charger, though. Probably have to borrow a few extra parts from another car to make that work...

-- Joe

[jangell]

If you think there is a issue with your IAC you need to address it. If it is not functioning properly it will be introducing more air than the engine needs and causing it to run lean.

That's exactly what I'm worried about. I did test the IAC when I put everything together. Here's a video of me running the test, then realizing that the pintle isn't actually secured in any meaningful way: https://youtu.be/VQgLUD9oGJ8

Luckily I had a second IAC.

I'll try and pull it this weekend and see if it's still moving correctly. Maybe a wire got damaged or something. Or something in the software isn't set up right, and it's not actually doing anything.

-- Joe

[FABombjoy]

Yeah, that's pretty impressively bad. I'm a software developer, so I kinda get where they're coming from (extremely rare case that has never been reported in two decades or so), but I don't work on stuff that can get people killed if something goes wrong. You'd think they might just add a maximum injector open time to avoid the risk of that kind of problem.

The firmware was legit corrupt, so you can't fully hold the device responsible for what happens when booting up in a random state. I suspect it booted far enough to engage the pump and purge the injectors and then crash. That suggests that firmware should self-checksum its startup routine and halt on failure.

And, if the firmware loader first executed a program that resets outputs to low before starting a flash, that would have prevented a lot of mess too.

All due to leaving keys in ignition and on all night. I can't recall what captured my attention after getting home causing me to forget my keys, but I know what captured it for 4+ hours the next day!

That's exactly what I'm worried about. I did test the IAC when I put everything together. Here's a video of me running the test, then realizing that the pintle isn't actually secured in any meaningful way: https://youtu.be/VQgLUD9oGJ8

Mind did this until I fixed the wiring. It seemed to work but slowly unscrewed itself. I hooked it up per (what I thought was) the correct way in the megasquirt manual. In the end I just randomized the wires until it started behaving normally during the test mode. MS3 has a mode where it just cycles in and out repeatedly which was a very fast way to get it straight!

[jangell]

Mind did this until I fixed the wiring. It seemed to work but slowly unscrewed itself. I hooked it up per (what I thought was) the correct way in the megasquirt manual. In the end I just randomized the wires until it started behaving normally during the test mode. MS3 has a mode where it just cycles in and out repeatedly which was a very fast way to get it straight!

Ah, now that's interesting. So you're saying that what's going on in my video is not what should be happening. My assumption was that this finding the limits -- that MS extended the pintle all the way to find the end position (by hitting it against the end of whatever hole it's installed in), then retracted it to an "open" position, because the AIC doesn't have any kind of limit sensors in it. I'll make some short jumpers so I can swap wires around and see what I come up with.

I used test mode, manually running it forwards and backwards, but I didn't see a "cycle forever" button. I'll check the software again this weekend.

Thanks!

-- Joe

(I did eventually find the pintle, BTW, but not the spring and one other part that is now probably sitting somewhere in the valley of death.)

[FABombjoy]

Only MS3 may have the cycle mode.

The pintle should cycle back and forth without launching off. I really did just floppy flop wire pairs until I *poof* it was working. I even have a spare IAC too as I was convinced the first was bad.

[Josh]

Only MS3 may have the cycle mode.

The pintle should cycle back and forth without launching off. I really did just floppy flop wire pairs until I *poof* it was working. I even have a spare IAC too as I was convinced the first was bad.

x2.

Seems like the sensor is wired in wrong. I dont know why I ever cut the connector off on the ecu side, it has caused so much confusion on your end. I really apologize for that.

I remember the wiring in the MS documentation to be wrong for two things: The IAC and the coil pack firing order.

[opethmike]

There should also be a throttle stop screw on the throttle body that you can adjust.

[Josh]

There should also be a throttle stop screw on the throttle body that you can adjust.

I already mentioned this but i feel it needs to be re-iterated.

No need to change the tune, sort out all the mechanical and electrical issues first.

[jangell]

x2.

Seems like the sensor is wired in wrong. I dont know why I ever cut the connector off on the ecu side, it has caused so much confusion on your end. I really apologize for that.

I remember the wiring in the MS documentation to be wrong for two things: The IAC and the coil pack firing order.

I'm sure the coil pack firing order is sorted. Don't worry about the connector: having to re-solder that is the only reason I know as much as I do about how MS is wired, and why I have my wiring diagram. If I really wanted plug-and-play I'd have had a shop just swap the engine out for me, and been done years ago. Now I'm getting much closer to having a complete understanding of the car.

-- Joe

[jangell]

I already mentioned this but i feel it needs to be re-iterated.

No need to change the tune, sort out all the mechanical and electrical issues first.

I agree -- the software isn't going to work if the inputs are bad. Thanks again

-- Joe