Help With Tune/Smoke

[thcraig87]

Hi All

 

I have a KE35 with a 100kw 4age. A rev at idle or putting your foot down when rolling leads to a fair bit of black smoke. So she is running way too rich. I larger fuel return line was installed at conversion to meet emissions expetations, which I don't think it would meet anymore.

 

I'm just looking for ideas on where to start. The first thing everyone says is tune and yes at one point the stock computer must have been running it with the right mix, but maybe not anymore. How much can be done with the stock computer (if it is still working alright)? Is it worth taking to the mechanic? Is there anything else I could have a look at before we get there?

 

Fianlly has anyone had any good or bad experiences with aftermarket computers in a NA 4age? Suggestions... is it worth it?

 

Cheers

Craig

[Trev]

Check the MAP sensor and plugs.

Edited September 20, 2010 by Trev

[ke70dave]

do a system diagnosis on the ECU and see if a sensor is playing up.

 

what does your fuel system comprise of?

 

if your fuel pump is miles to big, it will cause to much fuel pressure as the fuel pressure regulator cannot control it. i tried a bosch 040 fuel pump on my 16V and my fuel pressure was up to 40-45psi, when its supposed to be around 35psi. high fuel pressure = running rich (since the ecu is expecting lower fuel pressure, and opens up the injectors X ms)

 

then if you can rule out sensors or fuel pressure, move onto your plugs, but generally if its firing on all 4 cylinders then they should be alright.

 

apparently the tune on a stock 4age computer is pretty good, and not much power can be gained from an aftermarket ecu.

 

however,

 

aftermarket ecus are much easier to diagnose problems, you can physically read off the values that the ECU is recieving from each sensor (assuming you can use a laptop etc)

 

and also aftermarket ECU installs are much cleaner, you can throw out 90% of the wires in your engine loom as the ECU only requires ~15wires to work. especailly in a bastardised car (like yours, 4age in an older car) wiring looms can be very mess (i know mine is)

 

in my oppinion its not worth getting an aftermarket ecu untill you have some mods that require it (camshafts, quad throttles, turbo, extra compression etc).

 

if you arent handy with wiring you will pay ALOT for someone to install one, and then you never know how good of an install it is, might be just as dodgy as you can do....

 

those new haltech sprint 500 ecus look pretty nifty, and for about $1k its a good deal i reckon.

[Trev]

If the pump was too big it would go into bypass and most likely fail.

[altezzaclub]

Trev how does the MAP sensor work??

 

The Altezza runs a MAF sensor by sampling the incoming air over a heated wire, and I know that they get diry over time. A 15minute job to clean it often gets rid of several small problems involving rich running or stumbling.

 

Does that happen with a MAP?

[Evan G]

Manifold Absolute Pressure (MAP)

The Manifold Absolute Pressure sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. The computer sends a 5-volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the computer can determine the manifold absolute pressure. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum, which requires less fuel. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the computer to automatically adjust for different altitudes. The computer uses the MAP sensor to control fuel delivery and ignition timing.

[Trev]

Trev how does the MAP sensor work??

 

The Altezza runs a MAF sensor by sampling the incoming air over a heated wire, and I know that they get diry over time. A 15minute job to clean it often gets rid of several small problems involving rich running or stumbling.

 

Does that happen with a MAP?

 

MAP measures the Manifold Absolute Pressure, it is not an intake item persay but is a little box on the firewall that is connected to the manifold, will run without it but can make it run rich.

 

Bloody evan.

Edited September 20, 2010 by Trev

[altezzaclub]

Ok, that's quite different.

 

So what does Craig have sensors for?

 

Water temp

 

Throttle position?

 

Air temp?

 

MAP for air intake volume

 

O2 sensor in the exhaust.

 

and if one of those is sending the wrong signal then the computer thinks the mix is lean or the engine should be on choke.

 

I'm a carb man and will shit myself the first time the Altezza gives trouble!

[Trev]

Ok, that's quite different.

 

So what does Craig have sensors for?

 

and if one of those is sending the wrong signal then the computer thinks the mix is lean or the engine should be on choke.

 

I'm a carb man and will shit myself the first time the Altezza gives trouble!

 

Water temp - yes, affects fuel metering at different temps.

 

Throttle position? yes, affects rev time more than anything.

 

Air temp? yes, will go to a default setting if not used and should not over fuel the way he explains, just put one if mine after running it without one for over a year.

 

MAP for air intake volume, yep.

 

O2 sensor in the exhaust. yeah but doesn't monitor fuel like late models.

[altezzaclub]

So, a false reading from the O2 sensor in the exhaust could say "the mixture is too lean"

 

and a false reading from the water temp could say "the engine is still cold"

 

and eitehr MAP &/or TPS could say "the throttle is wide open and needs lots of gas"

 

 

That's even before you consider problems with the ECU.

 

Can you check these sensors with a voltmeter?

 

(having spent a year fixing washing machines and dishwashers that are crammed with sensors and ECUs!)

[Trev]

So, a false reading from the O2 sensor in the exhaust could say "the mixture is too lean"

 

and a false reading from the water temp could say "the engine is still cold"

 

and eitehr MAP &/or TPS could say "the throttle is wide open and needs lots of gas"

 

 

That's even before you consider problems with the ECU.

 

Can you check these sensors with a voltmeter?

 

(having spent a year fixing washing machines and dishwashers that are crammed with sensors and ECUs!)

 

o2 doesn't really affect the running of them.

 

Yes.

 

Yes but you would notice rough running when you put your foot down.

 

and yes.

[altezzaclub]

Well, there you go Craig- Check that the sensors are sending the correct info to the ECU first.

 

Someone on here will know what voltages they should be putting out at normal operation.

[Trev]

Well, there you go Craig- Check that the sensors are sending the correct info to the ECU first.

 

Someone on here will know what voltages they should be putting out at normal operation.

 

Would be better off lending him my book instead of writing them out.

 

Or I might scan it.

Edited September 20, 2010 by Trev

[thcraig87]

Sweet thanks guys it's all really good info.

 

I did some more research on the car and found out that the previous owner had the same problem. He took it to a mechanic and the diagnosis was fuel pressure was too high and that is when they put bigger lines in and out of the surge tank and a couple of others. It's running a VL turbo fuel pump with a Bosch primer pump and a surge tank. I thought it seemed a bit of over kill, but I think the plan at the time was to make the engine bigger and better, but it never eventuated and I want to leave it as is. So this may still be the problem. How can I test fuel pressure?

 

In my research I also found that the mechanic said the sensors, including the map sensor, were working fine and within normal ranges. That was in 07 though and I think she has done a fair few k's since then. So how do I check their function? I have a voltmeter, I just need to know where to start, at the ecu for voltages or at the sensors?

 

On top of that trev can you please let me know just a couple of voltages?

 

Oh and Dave said do a system diagnosis. I would obviously need a mechanic for that right? What computer equipment do I need?

 

Was just thinking it might be the actual ecu, hope not, I had one go in a civic and it cost a fortune, bloody Honda love to charge. If it was the ecu and it was going back to a default mix, is there any easy way to see that?

 

Sorry guys, I've said it in a couple of previous posts, but I'm learning. It's what I bought the car for, to learn and have a hobby. Please pardon my... Uselessness.

 

Cheers

Craig

[Trev]

Sweet thanks guys it's all really good info.

 

I did some more research on the car and found out that the previous owner had the same problem. He took it to a mechanic and the diagnosis was fuel pressure was too high and that is when they put bigger lines in and out of the surge tank and a couple of others. It's running a VL turbo fuel pump with a Bosch primer pump and a surge tank. I thought it seemed a bit of over kill, but I think the plan at the time was to make the engine bigger and better, but it never eventuated and I want to leave it as is. So this may still be the problem. How can I test fuel pressure?

 

In my research I also found that the mechanic said the sensors, including the map sensor, were working fine and within normal ranges. That was in 07 though and I think she has done a fair few k's since then. So how do I check their function? I have a voltmeter, I just need to know where to start, at the ecu for voltages or at the sensors?

 

On top of that trev can you please let me know just a couple of voltages?

 

Oh and Dave said do a system diagnosis. I would obviously need a mechanic for that right? What computer equipment do I need?

 

Was just thinking it might be the actual ecu, hope not, I had one go in a civic and it cost a fortune, bloody Honda love to charge. If it was the ecu and it was going back to a default mix, is there any easy way to see that?

 

Sorry guys, I've said it in a couple of previous posts, but I'm learning. It's what I bought the car for, to learn and have a hobby. Please pardon my... Uselessness.

 

Cheers

Craig

 

If this was the case then after a few years you think the fuel pump would be dead.

 

Put a fuel gauge in front of the fuel rail (pump side).

 

Where are you located, might be easier to just look at it.

Edited September 21, 2010 by Trev