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How to install Brown Tops on LH 2.2!

945T man said:
First, you need to locate this connector, it's on your passenger side fender near the AMM:

Ground the red/white wire. The idle should drop. Go to the Idle Air Screw on the underside of the throttle body and adjust it(lengthen = faster, shorten = slower) until the idle is ~725 RPM, then disconnect the red/white wire you grounded before. The idle will surge, then settle, which is normal.
Click to expand...

Sorry to bring up an old post/article here, but I still just want to adjust my idle/base mixture, no browntops, just want to adjust the settings, that is all. But I, cannot get anything to happen. The line I quoted, when you say "Ground the red/white wire", do you have to ground it with a string of resistors (like in the pictures) or JUST ground it, to be able to adjust the Idle, because without the resistors, nothing happens.

Thanks.
 
I've also noticed this, Benson. Every time I ground the wire that's supposed to lock out the idle, nothing seems to happen. It's possible we've both got our idle screws set so that it'll idle at 900 RPM without the idle control, and when we ground that wire the idle changes so little that it seems like nothing's happening. I haven't monkeyed around enough to test my theory - been meaning to for 6 months now!

You need the resistors for the LED test light, not to ground the red/white wire.
 
Yesterday I had reached my wits end and took off the AMM, tested the potentiometre and found that it actually was working, and was turned so far to the left that it wasn't registering on my multimetre (on pins 2 and 6). So I turned it down, and started over. I was able to adjust the mixture a little, but it still goes rich as soon as I touch the Accelerator. So, now that I know the AMM potentiometer works, what would be more lean, HIGH resistance, or LOW resistance at the AMM terminals?

And Matt, I think that was the case actually, because I actually turned the idle screw waaay low before grounding the pigtail and then when I grounded it, the car stalls...that was a happy time, I actually got something to work!!!

But as a whole, my car is still super rich with any sort of throttle, and adjusting the amm while installed doesn't do much. So again, can you even tell me what would lean out the mixture based strictly on AMM resistance?
 
Adjusting the AMM takes time. I built a little test light the other day and monkeyed around, and it seems to take a few seconds and up to a minute for the computer to react to the new AMM setting. Adjust slowly, my son.

And Benson, you could have a few other troubles. I had a fuel pressure regulator that was fine off boost, but gave rediculously high pressures in boost. I'm not sure why that would be, since a failure is generally a failure. Ian also had a rich running problem that turned out to be the one-way valve, though now that I think about it I'm not sure how that could be...

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My question to you folk who've done the browntop / 2.2 swap is this: How badly was your ignition timing affected? Assuming the AMM signal controls the ignition timing as well as the fuel trim, adding a resistor inline with the AMM signal line should also tell the ICM that less air is entering the engine, which should call for a bit more advance. Granted you can dial out a bit of static timing at the distributor and hopefully end up at the same place under load, but this also effectively lowers the cruise timing and should therefore affect fuel economy.

The other question I have is: What about extreme cold starting? I imagine the AMM is ignored during cranking, so no matter what tricks you've performed on the AMM signal, during cranking things are going to be quite a bit richer. Knowing Megasquirt and extreme winters like I do, I know that the car is relatively insensitive to excess fuel during cranking and is difficult to flood, but it can be done.

My plan is to install small CFI injectors (similar to browntops) and a 4 bar regulator along with a Fredchip, and drive it all year 'round. If this is not going to work, I'd prefer to know ahead of time and sell the chip, trade the injectors for something bigger, and run 'squirt. Obviously the 2.4 guys can leave their experiences out of this, since it's a completely different animal.
 
Matt, I would not worry too much about that.

Sure, the resistor on the AMM is a kind of "bandaid" that actually offsets a large part of the map (intead of skewing it which is what is really desireable).

But the maps are skewed in the other direction (more ignition advance down low), so that will instead affect how much timing you will be able to dial in on the distributor before it starts to ping at low rpm and low load. The ignition advance will in most cases be too retarded up top in this case.

Most of the time on LH2.2 we are use to giving it as much advance as it can take at the desired boost level we are running. When doing the AMM trick, the result will be the opposite and the timing will be advanced down low, and that is what you are adjusting the distributor for to counteract ping. This in turn will make the timing at high(er) boost be a little bit more retarded than desired.

It should work like this, at least in theory. You may of course get different results in reality depending on your other mods. Maybe the ignition curve is even more suitable now (if you have a cam that gives more torque up top it would probably be a good match actually since the ignition timing will be a little more retarded, and in that case it is desireable).
 
Fred, that's not how I would have expected to see it. At cruise RPMs and relatively high vacuum (low flow thru AMM), the ignition lead time might be so close to "fully advanced" on a stock system that reducing the apparent flow thru the AMM by adding a resistor might not give you any more advance, and what little you'll get by the reduced AMM signal would be more than offset by the amount you'd have to dial out of the dizzy to get near-detonation at full boost.

Not to mention that with a more aggressive camshaft, more advance is required down low with a little less on top, which would compound the problem I perceive.

Since you've got an "in" with a chip provider, you've probably got access to stock fuel and timing maps, based on Load x RPM, correct? Is there any way you can post this info? I would find it very useful...
 
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Matt Dupuis said:
Fred, that's not how I would have expected to see it. At cruise RPMs and relatively high vacuum (low flow thru AMM), the ignition lead time might be so close to "fully advanced" on a stock system that reducing the apparent flow thru the AMM by adding a resistor might not give you any more advance, and what little you'll get by the reduced AMM signal would be more than offset by the amount you'd have to dial out of the dizzy to get near-detonation at full boost.

Not to mention that with a more aggressive camshaft, more advance is required down low with a little less on top, which would compound the problem I perceive.
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Usually when raising the boost, making mods, whatever... then you usually adjust the timing at the distributor so that you will not get any ping at max load.

But...

When you put a resistor in the AMM line, the ECU and EZK will think that you are using less air than you actually are. That makes the ignition advance more, and get a little bit more tricky.

And... Since the EZK map is offset and not skewed (the AMM signal is not linear to air-flow as you know), the results will be these: You will need to adjust the ignition not to ping on low(er) load and low(er) rpms instead of adjusting it at full load. The ignition advance will then not be as advanced as it could have been at the higher load and rpm regions.

Matt Dupuis said:
Since you've got an "in" with a chip provider, you've probably got access to stock fuel and timing maps, based on Load x RPM, correct? Is there any way you can post this info? I would find it very useful...
Click to expand...
* The maps for LH2.2 and LH2.4 looks different.

* The maps between the ECU numbers look different.

* The tuned chips for each ECU number looks different.

* The LH system is more advanced that that, and utilizes more than just a load vs. rpm map. It uses a lot of maps and correction maps.

* The base map will not look the same as the map looks like when you drive.

But I can try to get one (graphically represented). Then the map will probably be from a 984 ECU. Or is there any other ECU that you would desire to have presented?
 
Thanks for that, Fred.

I understand that several different maps are used, but I assumed that the basic fueling and ignition calculations were based on load (represented by AMM voltage) and RPM. Since this topic is centered around LH 2.2, I'd prefer to stay on topic and discuss 541 maps if those are available.
 
Matt Dupuis said:
Thanks for that, Fred.

I understand that several different maps are used, but I assumed that the basic fueling and ignition calculations were based on load (represented by AMM voltage) and RPM. Since this topic is centered around LH 2.2, I'd prefer to stay on topic and discuss 541 maps if those are available.
Click to expand...
I will get them graphically represented. It may take some time though, but they will be posted.
 
I need more info. If this is a B280E we're talking about, you'll have Motronic and no O2 sensor, so it won't take well to bigger injectors. If it's a B280F you'll have LH 2.4 which can learn for bigger injectors.
 
i don't have a cat or any sensors in the exaust so i dunno. heres a pic of the engine you might be able to work it out.
264710128_694a197216_b.jpg
 
FYI
Step #2 says
"Disconnect the injectors. Mark each line with masking tape so you remember which one goes where."

You do not need to mark the injector plugs as is does not matter what injector goes where and what plug goes to what injector.

A.
 
gale said:
You do not need to mark the injector plugs as is does not matter what injector goes where and what plug goes to what injector.

A.
Click to expand...

I trust you speak from experience?

I'm a wee bit skeptical of that statement. Everyone else I've ever talked to warned me to make sure everything goes back together as it was before hand.
 
You could switch 2 & 3 and 1 & 4, since those pairs fire at the same time, but you can't switch them all up.
 
D Hulting said:
You could switch 2 & 3 and 1 & 4, since those pairs fire at the same time, but you can't switch them all up.
Click to expand...
I would normally say that it doesn?t mater since they all are triggered from the same wire off the ECU. That is at least true for 100% of the LH2.2 ECU's, 95% of the LH2.4 ECU's and 80% of the LH2.3 ECU's.

However...

LH2.4 ECU's with batch fire do exist for 4-bangers. They also exsist for I6 engines.

So do LH2.2 ECU's (only in I6/V6 applications).

LH2.3 ECU?s normally comes with two banks of injector drivers and they are all batch fire (in the hardware). If they use the batch fire or not is up to the software and in which cars you mount them (normally Porsche's).
 
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