help for porsche 986 2.5

[cruz177]

Hi everyone and thanks for this space to ask questions.

I'm trying to boot my porsche 986 2.5 of 99 with ecu storm

I have trouble keeping the car in idle since it works very badly and stops

I am a little lost in how to adjust the base time and which one corresponds. I currently have the following:

What would be a good starting point for this engine?

Thank you

[Adamw]

Im not sure if you were intending to attach something but there is nothing attached to your post.

Can you attach a log and the .pclr file.  Here is a video showing how to record a log and save the map:  https://www.youtube.com/watch?v=_P1LRANeO4A

 

[cruz177]

Hi!

Thanks for aswering

I have attached the pclr

I have set the base time to 5 degrees to try. According to the porsche manual I understand that the base time is 5.3 degrees btcd. Would my adjustment be correct?

porsche ultimo.pclr

[Adamw]

The only way to find the correct trigger offset is with a timing light.  

[cruz177]

Hello if I have already done this (attached image).

I found the engine tdc and coil 1 is already firing when the cylinder is up

The problem is that once the car has been started, I can't find how to keep it active without turning it off.

Thank you

[Adamw]

Sorry, I dont understand what you mean.  Do you mean it loses the change after you turn off the ignition?  Did you do a store after making the adjustment (press F4)?

[cruz177]

my problem is that I do not know how to make the ignition table I do not know where to start as a reference because the car starts but if I release the accelerator it stops and just responds

I don't know how to start to keep it in idle

Thank you

[cj]

your ignition table itself looks like a good starting point

the trigger1 offset you have to find yourself with a timing light as suggested by Adam. It can be different on each engine so we cant tell you exactly what number to use. remember to press enter after typing in an offset to get it to stick.

As for your idle issue, maybe fuelling? Can you post a log of it happening please? Also disable launch control, its set to "on with DI4/clutch switch" so may be on accidentally which will pull 10deg of timing and other things unhelpful to idle.

Unlikely to be your idle problem but I suspect there is something wrong with your oil temp sensor (shows a reading of -33C when ECT & IAT are both ~20C), and you engine compartment temp gauge is reading in KPA because of its calibration, which makes no sense at all.

[cruz177]

hanks I managed to keep it in idle and accelerate it well

The variocam advances 25º the base map from about 1400rpm, should it delay something on the ignition map telling that the variocam will advance these degrees? or how should I adjust it

I am afraid of going on too much ignition because of the variocam

Thank you!

[cj]

As I understand the variocam on these engines is just on/off intake cam phasing by a fixed amount? In this case, its only the intake valve opening & closing angles that are advanced relative to everything else in the engine. Your spark timing is not affected by this.

Assuming the engine is all stock, there will be mechanical stops to prevent over advance to the point where you get piston-> valve clearance issues. At which point the only place you need to consider this from a tuning persepctive, is that the fuel cells between 1300rpm & 5200rpm will need to be a bit richer because of higher VE. If you change the cam switching parameters then you likely need to adjust your fuel table cells that move from "in" to "out" of the variocam activation range or vice-versa.

If you think its impacting your idle, just disable it by disabling aux 7 & 8 or change the rpm limit up to 4k or something way above idle, then turn it back on later. I suspect this is not your issue though, and its more likely to be incorrect fuel table values/master value & that you have closed loop idle control enabled & are hoping this will automatically sort out your idle valve settings, but probably haven't run through the open loop calibration first (see the help file for this process).

[cruz177]

Thank you

I attach a couple of captures but I don't understand why the workshop manual says 5th cnk while at 5th the car works very badly.

I currently have it at 25º to maintain an idle that seems stable but I don't know if the time I have can be dangerous or is correctly. I also don't know how I can adjust the time reliably

Thank you

[cj]

So basic engine/idle theory... **assuming your trigger1 offset is correct**

engine power output is from compressing & igniting fuel + air. The more fuel + air you have in the cylinder, the more potential power. The ignition angle (ie "when" you ignite the mixture in the 360* cycle) determines how much of that potential power is actually created. In 95%+ of petrol/ethanol engines, you "control" the air intake, and the computer/carb adds an appropriate amount of fuel to match.

To have a stable idle, the engine output power (torque) must equal the amount required to keep the engine turning over. Any less & it stalls, any more and the revs increase.

So the 2 levers you have to pull to get a stable idle (at any rpm) are

1) how much air you let in

2) what ignition angle you fire the spark plugs at

You are only changing #2 here, but it sounds like you have #1 a bit off vs the factory specs. 25* ignition at idle is quite high, so I suggest you need to increase the air flow at idle - either idle stop screw on the throttle, or increase the idle control settings in the ECU to allow more air. You will then see your idle jump up to higher rpm, and when you reduce the ignition table values it should come back down. I cant give you exact values, but typical factory ignition idle angles are usually in the 10-20* range, and in your case it sounds like the manual says 5*. You dont have to match this exactly as your idle numbers can also differ from factory, but its usually a reasonable starting point.

You are extremly unlikely to have knock or other spark related damage at idle speeds, so there is no real "dangerous" ignition number for idle, its just what works well for your car. Knock only becomes an issue as the engine comes under mid-high load (note that low rpm can still be high load however when you press the throttle hard)

[cruz177]

22 hours ago, cj said:

So basic engine/idle theory... **assuming your trigger1 offset is correct**

engine power output is from compressing & igniting fuel + air. The more fuel + air you have in the cylinder, the more potential power. The ignition angle (ie "when" you ignite the mixture in the 360* cycle) determines how much of that potential power is actually created. In 95%+ of petrol/ethanol engines, you "control" the air intake, and the computer/carb adds an appropriate amount of fuel to match.

To have a stable idle, the engine output power (torque) must equal the amount required to keep the engine turning over. Any less & it stalls, any more and the revs increase.

So the 2 levers you have to pull to get a stable idle (at any rpm) are

1) how much air you let in

2) what ignition angle you fire the spark plugs at

You are only changing #2 here, but it sounds like you have #1 a bit off vs the factory specs. 25* ignition at idle is quite high, so I suggest you need to increase the air flow at idle - either idle stop screw on the throttle, or increase the idle control settings in the ECU to allow more air. You will then see your idle jump up to higher rpm, and when you reduce the ignition table values it should come back down. I cant give you exact values, but typical factory ignition idle angles are usually in the 10-20* range, and in your case it sounds like the manual says 5*. You dont have to match this exactly as your idle numbers can also differ from factory, but its usually a reasonable starting point.

You are extremly unlikely to have knock or other spark related damage at idle speeds, so there is no real "dangerous" ignition number for idle, its just what works well for your car. Knock only becomes an issue as the engine comes under mid-high load (note that low rpm can still be high load however when you press the throttle hard)

Thanks for the help

I have been adjusting the ignition based on the 5º of the manual and the 35º at maximum rpm that I have seen that some coach quotes in the porsche 986/996 variocam engines

How can you see it as a starting point to move the car and try a driving test?

On the other hand I can not fix the idle problem as you can see in the photos is very low

I have tried to increase the work of the idle valve but I do not see that it has an effect on the air flow and therefore at higher rpm

I am doing something wrong?

Thank you

[cj]

Can you post the config file you are currently using, and a log of its starting+idling? It will be a lot easier to help with all the info available.

If you think the idle valve control is having no effect, try removing the idle valve from the car, but leaving it plugged in, then try making the valve move via the ecu config. You should see it open & close

Did you follow this process to wire up the solenoid? If you have it backwards it will not function correctly.

[cruz177]

thanks I had a problem in my solenoid and now it works correctly

I went to test the car and it works very badly, there is a very strong vibration of the engine as it does not work properly and has no power

I tried to deactivate the variocam and it seems to be a little better but I don't get an ignition table for my engine

Is there any way to know how many degrees each box has to have or to know when the engine starts to knock? I don't know from what point to start

thanks

[Adamw]

Have you confirmed that the base timing (trigger offset) is correct yet?

Assuming your engine is not turbo you can use the attached ignition map as a starting point.  To load this table, right mouse click on your existing ignition table, then choose > import/export>import from file and choose this file.

 

Basic NA Ignition Table 1.lte

[cruz177]

If the trigger offset is correct, the light stays at 0 degrees with the strobe gun in tdc mark and I am not having explosions from the intake

It's a turbo engine but I'm currently trying to tune it without a turbo so I can move the car to another place

Would that board be worth my car? I attached a photo above the one that has attached me and below the one that I currently have

thanks!

[Adamw]

Your ignition map (the bottom photo) looks fine, that is close enough to run the engine fine.  If it doesnt run fine with this then your problem is not due to the ignition timing table.

[cruz177]

the problem is that the car is going to idle well I can even accelerate it to the cut without problem but at the time I do a driving test the car does not run more than 60km / h because it runs out of power.

There is also a very strong engine shake as if it had the unbalanced wheels coming from the engine starting 1500rpm drive test. the engine is fine because it is exactly the same as with the ecu stock so I think it could be a failure in ignition table

It may be possible that you are very advanced / late ignition and do that? How can I know that?

thanks

[cj]

can you post the config as it is now, and a log of you starting + driving it?