Megasquirting a A20A3

[cougar97536]

The coolant sensor didn't seem to be working in the first few runs. In a latter run, the coolant temp shot up to 300+ whenever an air bubble got into that area of the cooling system, I think the calibration is just way off. I will try messing with it again soon. I didn't remove the idle air valve off the back of the intake, the one with all the coolant hoses running to it... should I have removed that? I am now running the extra code, and it really did change things in tunerstudio... but I have it idling again... still at 2000+ cold and 1500 warm though. I am headed out to address these issues now... My O2 sensor also appears to be FUBAR, can I tune my idle-low load by the seat of my pants? Will this hurt anything exept my spark plugs? If I am careful and stay on the rich side?

[cygnus x-1]

I got her to run! Right now though she is idling at about 2100 rpm, and has to be bottle fed to start her, then she can take care of it herself...

That could possibly be the fuel pump, or it could be the cranking pulse width too. More below...

Also, is it common to have the oil pressure switch fail on these engines? I just noticed my light is on, and I am a little worried, I did however look at the main and rod bearings when I had the pan off, and they looked good, so I am unsure what I could have done to make this a real problem.

Mmm, the connection is still ok? I've never heard of one failing but it's possible. Can you swap it with the old one?

The coolant sensor didn't seem to be working in the first few runs. In a latter run, the coolant temp shot up to 300+ whenever an air bubble got into that area of the cooling system, I think the calibration is just way off. I will try messing with it again soon.

Ok, yeah. Sounds like the cal is off.

I didn't remove the idle air valve off the back of the intake, the one with all the coolant hoses running to it... should I have removed that?

I would leave it for now. If you take it off you'll have to plug the holes. And you might want to use it some day.

I am now running the extra code, and it really did change things in tunerstudio... but I have it idling again... still at 2000+ cold and 1500 warm though. I am headed out to address these issues now...

If it won't start at all without extra fuel then the cranking pulse width may need to be increased. If it starts but then dies after a second or two then the ASE percentage and maybe taper needs to be increased. Incidentally I've always seemed to have some minor issues with this. Mine is kinda grumpy for the first 30 seconds or so at startup unless I rev it up to 2000RPM or so. As far as I can tell it's because I have no idle valve for fast idle at all.

My O2 sensor also appears to be FUBAR, can I tune my idle-low load by the seat of my pants? Will this hurt anything exept my spark plugs? If I am careful and stay on the rich side?

I would stay on the lean side actually. At low loads you can run as lean as it will go because there isn't enough mixture in the cylinders to be able to cause any damage, even if it did detonate. In my experience these engines don't like really lean mixtures though. The combustion chamber shape isn't as optimized as on newer engines, so it starts to misfire if you go any leaner than 16:1. You can tell this is happening because it's starts to surge and feel sort of nervous and wheezy. It won't hurt anything, it just doesn't run so great. I find that 15.5:1 is pretty good at loads up to 50-60kPa.

But you don't have a wide band O2 yet so don't worry about the AFR for now. Just tune so that it feels good and doesn't smoke or surge.


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[cougar97536]

I finally got it to idle about right, I had to unplug the dash pot. It now is adjustable with the idle screw. I also replaced the O2 sensor, and now am getting a signal in TunerStudio that changes with the engine... so I think it works. Coolant Temp problem was I was hooked into the fan switch for a fuel injected car, apparently on the latter A20A3s they had that sensor in the therm housing, once I plugged into the correct port on the therm housing, the readings now look correct in TunerStudio... Progress is being made...
Now I just need to get my VE table in order, and the acceleration enrichment sorted.
Thanks much for help...

[cygnus x-1]

Awesome! It's a great feeling when it all starts coming together isn't it? It will be interesting to see how you get on with tuning with the stock O2 sensor.

I need to get mine put back together and running, now that the weather is starting to warm up.


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[cougar97536]

Evening Update:
The cruise settings in the VE Table are about there, I feel like I can drive the car now.

The clutch is FUBAR, I have maxed out my adjustment, and it still slip a little if you get on it at all, I will look for a screw up in pedal connection tomorrow...

It is having an issue where once it has been driven a while, where it will stutter at an idle. I have tried richer, and I have tried leaner, and nothing seems to fix this when it decides to do this...

Chris, you really should get yours together man, seems like you love working on your car as much as I do, and I would go nuts without a running car, or three... I am CAR POOR!!!

Have a nice one y'all

[cougar97536]

Evening update:
I have just completed a 300+ mile trip with the car, and everything seems to be coming together... My table now kind of looks like I have a clue, and the power is much improved from the old motor, the butt dyno can see a big difference...
Also, the clutch turned out to have the cable not in all the way at the pedal end, causing it to not have enough travel to fully release, fixed that bugger this morning...
Have a great one y'all,
CK

btw pics will be up soon (read tomorrow) of the nearly finished product!

[cougar97536]

Here are a few pictures of the project as it sits now, I will be cleaning up-Fixing things for the next few days, then I will post more pictures, with better lighting I promise... I also installed a set of brand new NGK spark plugs today... and drove the car some more... she has a lot more pickup than she used to... makes me happy, It actually is pretty respectable for the commuter car I want this thing to be when complete.

Here is the Engine Compartment as a whole, as of tonight...


and the left hand side of the bay:


and the black box of death is GONE!!! here is proof for all those who doubted it was possible...


Have a great one everyone... all two or three that actually might be following this...

[cygnus x-1]

Excellent Smithers! One more step towards ECU world domination is complete!

Evening Update:
Chris, you really should get yours together man, seems like you love working on your car as much as I do, and I would go nuts without a running car, or three... I am CAR POOR!!!

Actually I have 3 vehicles but only one of them is fully operational at the moment. The Prelude is undergoing brain surgery right now along with some minor upgrades; all in preparation for a couple BIG upgrades sometime this summer. My Nissan is pickup is the current daily driver. My Suzuki Samurai is theoretically operational but it burns oil so bad you can't drive it very far without getting a headache; unless you take the top off. Too many projects and not enough money/time.


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[cougar97536]

CJ, in the table you sent me, that bottom row really that low-lean, or does the wide band sensor and the AFR table deal with this, I am going to try really leaning out my lower row, I just don't feel comfortable going anywhere near as low as you have without confirming this first. I am also guessing that where those four 18s, between 30 and 35 kpa are is your idle location correct?
The help is greatly appreciated,
CK

[cygnus x-1]

CJ, in the table you sent me, that bottom row really that low-lean, or does the wide band sensor and the AFR table deal with this, I am going to try really leaning out my lower row, I just don't feel comfortable going anywhere near as low as you have without confirming this first.

That bottom row is when the throttle is completely closed and the car is actually pushing the engine, not the other way around. Some ECUs even cut fuel completely under those conditions to save fuel. In my case the VE values are so low because that's what was required to keep the AFR from being way too rich. The mixture there is really not as lean as it would appear. It's just that there is so little air getting in to the cylinders, that even the tiniest amount of extra fuel makes the AFR way rich.

Honestly that part of my table is not really so good. One possible cause for this is that I have the opening time for the injectors set too high, so that more fuel is getting in than it thinks there is. But it could also just be not so accurate readings from the wide band. Really it doesn't much matter because the engine is under negative load and there is hardly any mixture burning at all.

I am also guessing that where those four 18s, between 30 and 35 kpa are is your idle location correct?
The help is greatly appreciated,
CK

Yup. The best way to tune the idle is by sound and feel. Lean out the mixture until the idle RPM starts to drop, then richen it back up again until the RPM gets back to its high point. That high point is what you want and every engine is a little different in what it wants. For some reason my engine likes a really rich idle. Others are ok with a leaner idle.


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[cougar97536]

Well, I have been having fun chasing a squeel under the hood of the car for the last three days... It happens from about 1000-2000 rpm, then disappears I have just about decided that the timing belt tensioner is no good - out of adjustment from when I installed the new belt. along the way, I put in another new water pump, and hand my alternator checked, as well as checking the belt tension, and inspecting the accessory belt... This car is toying with me, and I don't like guessing games...
Have a great one y'all, Ill keep all three people reading this updated...
CK

[cougar97536]

Update, the sound is now GONE!!! It turned out to be the alternator like I thought at first, had it tested, the gent said everything checks out... so it now has a new timing belt tensioner, new water pump(2nd new one), a new accessory belt, had the clutch cable adjusted, along with the new alternator that I just installed... but it is now fixed... and all but the water pump should have been done anyway I guess... Now I just have to figure out what is wrong at the gas tank, it smells like gas every time I take a turn, until the tank gets to about a half, then all is well.
Have a great one y'all,
CK

[cougar97536]

Update:
Well, the noise came back... turns out its the throwout bearing, I have just got back from the Autozone, where I ordered a LUK clutch kit. Should have it in the car soon. Then I can finally get around to cleaning up the engine bay, just been to busy driving it to school (it's my only car) to take it down to fix all the little things right now.
Have a great one,
Christopher

[2ndGenGuy]

Woah, are you guys both named Chris?

Glad to see you updating the thread. I've been following along, as it's another one of the more interesting threads here!