Rexanne!

[Herman]

Made a little bit of progress over the weekend...

First off time to remove the stuck stud, which would have been too short to use with the adapter plate and made the manifold less likely to seal. So, after welding on a nut and a little aggro...





Hey presto! Off it came

Core plugs fitted...



Making a manifold gasket, template and the gasket itself:



Making the ITB to manifold gaskets:





Clean-up operation - RTV everywhere!







Shiny Shiny!



Now to put it back together. Here you can see the new, longer central studs fitted.



(I decided to use O-Rings between engine and adapter as well as the core plugs, just to make doubly sure it seals.)

12a gasket (£4.62 from Mazda - wohoo!! )



Adapter plate on, torqued up and the next lot of studs fitted:



Hand-cut "13B" gasket on. (Mazda wanted over £32 for this one, which is odd given the 12a one was so cheap, hence I decided to go DIY )



Inlet to ITB gaskets, new studs, nuts and washers.


Fitted to the car...


Finally, back on with the throttle bodies, connect up the brake servo pipe and throttle cable.



Steve's mums / girlfriend's tights have seen better days, so I'll change those another day. (I don't know any women though, so I'll have to use my own hosiery... )

...For now though, time to RELAX

[Herman]

Small update from tonight:

I filled it with antifreeze, started her up on the cold idle... All good so far... Even better, that once all the old crap had burnt off, there way no sign of any coolant leak... HOORAY!

When warm, I noticed it hadn't come off fast idle, (by this point it was properly warm, coolant at 87 degrees and the fan coming on.) So I pushed the choke in and... it died straight away. Tried the same again but pushing the choke in slowly and trying to feather the throttle - same thing. Any which way I tried it, it won't idle.

Now more than likely, I've probably ballsed something up putting it back together and introduced an air leak. (Tomorrow I'll break out the ether to try and track it down.) But I'm pretty sure that if anything, things are back together sealed better than before. So is there anything else I could be missing? E.g.

- Does the Megasquirt lose it's map when you leave the battery disconnected for any length of time? (Steve!? Question for you I guess!)

- Could I have f***** some of the wiring in taking the ITB's off? Losing which sensors from the inlet side might cause these symptoms?

- Any other ideas, aside from the above or an air leak?

[RamoNZ]

Small update from tonight:

I filled it with antifreeze, started her up on the cold idle... All good so far... Even better, that once all the old crap had burnt off, there way no sign of any coolant leak... HOORAY!

When warm, I noticed it hadn't come off fast idle, (by this point it was properly warm, coolant at 87 degrees and the fan coming on.) So I pushed the choke in and... it died straight away. Tried the same again but pushing the choke in slowly and trying to feather the throttle - same thing. Any which way I tried it, it won't idle.

Now more than likely, I've probably ballsed something up putting it back together and introduced an air leak. (Tomorrow I'll break out the ether to try and track it down.) But I'm pretty sure that if anything, things are back together sealed better than before. So is there anything else I could be missing? E.g.

- Does the Megasquirt lose it's map when you leave the battery disconnected for any length of time? (Steve!? Question for you I guess!)

- Could I have f***** some of the wiring in taking the ITB's off? Losing which sensors from the inlet side might cause these symptoms?

- Any other ideas, aside from the above or an air leak?

My first question would be - why does it have a choke if its running EFI? The choke was designed to create a higher vacuum pull to both restrict the air and increase fuelling to make the rich mixture needed for cold starts. If its only running with the choke then it must be to create a larger MAP signal thats lacking from the ITBs? I think a hose must have vacuum come adrift or been plugged into a lower vac source, which is somewhat rectified by increasing the vac to where it should be at idle.

ps - the megasquirt runs NVM so wont lose any data on power off.

[Herman]

I don't think it's a choke as such, more a 'fast idle' control - but I'm sure Steve will be along in due course to confirm (or deny!)

I will check that the vac piping is plugged back in OK. Presumably and air leak somewhere would cause exactly the same symptoms though?

[RamoNZ]

OK - that kinda makes more sense as it wont have a IAC valve to control fast idle - manual IAC based on a choke cable - ingenious!

Wont idle when warm in this case means that the TPS adjustment is out - you'll have to check on screen to see what the TPS is reading in % with the fast idle pulled, and as you push it back in - sounds like its seeing some odd value and the map dont like it in that spot hence the stall.

[Steve-A]

The gaskets look nice and neat there, nice work.

Most fuel injected motorbikes use a throttle stop and a fast idle lever, to control idle, rather than the electro-mechanical IAC valve most car fuel injection uses. The fast idle just puts a second throttle stop into action that holds the plates open a bit, so there's no extra air passages or anything. I stuck with this system and hooked the fast idle cable from the bodies up to the choke lever and magnet in the FB. One of the nice bonuses with this is that the idle should drop automatically when the engine gets warm, just like the semi-auto choke cutting out on the standard carb. It should pop in about 40° or so and idle happily from then on.

Unless you've unscrewed the TPS from the throttle bodies, its the black box with three wires going to it on the opposite side of the ITBs to the throttle cable, then the TPS values shouldn't need adjusting. I set then once when I installed the Megasquirt and then didn't need to tweak them.

As it idles using the MAP signal, an air leak should cause a high idle rather than a stall, but it's still worth looking into as when you've been resealing the intake manifolds air leaks are always the first port of call.

When the fast idle cable is released, the idle speed is controlled by a simple throttle stop. Its comes of the bodies just below the throttle linkage, and its got one of those flexy remote cables on it then a little plastic knob so it can be turned and adjusted by hand (again a motorbike thing, lots of bikes have these remove idle speed adjusters). It's fairly sensitive and I my first guess is that has been upset when you dismantled it. Wind it in a couple of turns and I bet the engine fires up and idles high, then once warm you can dial it back down to a sensible speed.

As a point worth knowing, because there's no automatic idle control you need to set the idle at about 1k rpm with the lights off and heater blower off. Then with lights, hater blower on max and the radio on it'll idle about 800 rpm. If you set it to a nice low idle with no electrical drain it can suffer from idle drop with the lights on!

If you've not already done so I'd download a copy of Tunersudio MS for free, and hook a laptop up to the megasquirt. You can start finding your way around the various tables, tuning tools and diagnostic tools. It's a nice feeling when you feel you understand most of it and why it's doing what it's doing!

[Herman]

Brilliant - cheers Steve, that's an enormously useful post!

The fast idle control all seems to be working as it should, which is nice.

I'm perfectly happy to admit I've probably done something retarded when putting it back together, but I was also thinking that an air leak usually causes a high idle rather than a stall.The 'remote idle control' is a VERY likely suspect (I wondered what that long plasticky thing was!) It probably got a bit mashed about when the throttle bodies were off. I'll have a play with it tonight. (Making sure I note it's current position, so I can turn it back if it turns out to be a red herring )

Regarding hooking up the laptop, do I just unplug the white cable (which I assume usually connects the Megview?) and plug the PC in there instead? (Sorry, I'm alright with cars, but completely new to tuning with computers!)

If there are any good tutorials that'll help explain the basics of the MegaSquirt & Megaview (hopefully without causing damaging the motor in the meantime), a shove in the right direction would be gratefully received!

[Steve-A]

Yeah, as you say, just remove the white cable where the Megaview plugs in, and plug in the laptop. Unless you've got a fairly old laptop with a serial port in it, you'll need a serial to USB adapter. The serial cable must be the straight through type.

If you've got a week to spare I suggest reading http://www.msextra.com . The car is running ms2 Extra v3.2.1 . The manuals on that site are invaluable for learning what Megasquirt can do, and understanding why things work like they do. The support forum is also great, though I've never needed to post, I've always searched and found the answer I needed.

[Herman]

Sorted.

Steve called it: The remote idle speed cable was coiled over post refit which was obviously upsetting for it!

The idle speed was still pretty lumpy until I fixed a split vac pipe (so I did have an air leak after all!) It's much better now, though still a tiny bit 'lollopy' on idle, so I'll double check everything is tight and sealing properly at the weekend.

Tuner Studio and MegaLog Viewer have been downloaded. Just need a serial cable now, then I can play at pretending to be in The Fast & The Furious !!!

Steve - Just saw your new avatar. Lancia purchase successful? Not relevant to you I guess, but my friend Sonia just started a club for Lancia owners in the Cape of South Africa: http://www.facebook.com/CapeLanciaClub

[Steve-A]

Glad to hear you sorted it. You might find a little tweak of the idle speed adjuster one way or another will smooth the idle out, but as a rotary owner you should be embracing the ropey idle, ready to get used to the stupidly lumpy brapping idle or a ported rotary

Indeed the Lancia purchase has been successful. There's more pics and chatter HERE if you're interested to see