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ECMlink Want help from ECMlink experts? Read this or receive no replies from the Wisemen

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Calan

DSM Wiseman
7,251
362
Jan 16, 2007
OKC, Oklahoma
In order for us to help with your tuning issues, certain assumptions about the mechanical state of your car have to be made on our end, since we can't see the car in person. Because of this, it is very important that you do everything possible to ensure that we are looking at what we think we are.

I'll go out on a limb here and speak for most of us that are willing to put our time and effort into helping with your tuning issues: This is a two-way street; if you don't put the effort into holding up your end of the deal and take care of the items mentioned below, don't be surprised if your help suddenly dries up and/or your thread is locked. You've been warned! :)

With that said, here is a list of things that you are responsible for checking and/or fixing, before asking for help with tuning. Please start your post with either verification or numbers (in the case of a compression test for example) for each item, so we can save time and get down to business.

1). No boost, vac, or exhaust leaks.

It is ABSOLUTELY VITAL that you have all boost and exhaust leaks fixed before doing anything with the ECU. Any leaks in the intake or exhaust (even small ones) will throw off the measured airflow and/or wideband, and will make the calibration and tuning process much more difficult.

This can't be stated enough. It is way too common to get involved with helping someone on a tuning issue, only to find out days later that they didn't "really" test for boost and exhaust leaks. "No boost or exhaust leaks" has to mean "Zero boost or exhaust leaks...nadda...zilch...none.".

One commonly over-looked vac leak is a VC breather vent that is not recirculated back to the turbo inlet after the MAF. This will not show up on a BLT if the PCV valve is doing it's job, but can cause problems when the engine is running in vacuum. If you have a breather hanging off the VC or it is running to a vented catch can, be sure to let us know this.

2). Verify mechanical timing.

This means making sure that all of your timing marks line up properly, and that you don't have any timing belt-related issues. Although problems with mechanical timing are usually fairly serious and obvious, minor problems or adjustable cam gears can affect tuning. If you are running adjustable gears, be sure to mention it along with how much advance or retard you have on each cam.

3). Verify base timing

Base timing on the 4G63 should be 5* BTDC. Don't guess at it; get hold of a timing light and verify it. It also wouldn't hurt to verify that the mark on the harmonic dampener still lines up with true TDC. Bring the #1 piston to the top of it's stroke, and make sure the dampener mark lines up with the TDC mark on the timing cover.

4). Ignition system

Make sure that your plugs and wires are in good condition. Plugs are normally gapped at .028", but may need to be gapped down to prevent spark blowout. If your plug gap is not at .028", tell us and let us know why.

It also wouldn't hurt to test your coils and PTU, to rule out any potential problems.

5). Motor health

We're talking about a compression and leak-down test here. If you can't get more than 70psi in cylinder #4 during a compression test, or air goes screaming out of cylinder #2 when you inject it into cylinder #1, don't ask us to look at a log to figure out why your car doesn't have any power. :)

6). Basic throttle body adjustments.

This includes properly adjusting and setting the idle switch, throttle cable tension, TPS (Non-V3 adjustment and V3 adjustment), and BISS (1g and 2g). There is a specific procedure for adjusting each of these, and they are critical to getting the engine to run right. If you don't know how to properly adjust these, learn. Don't guess at it or assume they are adjusted properly. If you are experiencing idle issues, please make sure to test your ISC, and check out this page.

7). Compression ratio

If you are running a high compression ratio (9.0:1 or higher) or a stroker setup, make sure it is noted in your profile or be sure to mention it. Higher compression pistons have a big impact on what you can and can't get away with as far as tuning.

8). Wiring and sensors

Nothing is more frustrating than chasing down gremlins hiding in the wiring, or intermittent sensor issues. If you know you have broken connectors or old brittle wiring, fix it. If you know your O2 sensor "sometimes works and sometimes doesn't", fix it.

9). No DTC/CEL codes

This feels like I'm stating the obvious, but there are plenty of people who try to tune and have DTC/CEL codes thrown. Make sure to clear up any that are there (get them read via a scanner to see what exactly is going on) or let us know that they don't affect anything (i.e. you have your wideband in the rear o2 spot which is throwing a CEL for a missing rear o2 sensor).

10). Electrical system

Make sure your electrical system is in good working order. Low battery voltage affects many aspects of performance, including fuel pump output, injector response, spark energy, etc. You should see between 12-13v at the battery with the car off, and at least 13.5v throughout the operating range while running. Keep in mind that additional accessory loads such as stereo amps and aftermarket lighting can put a drain on your electrical system, so make sure your alternator and battery are capable of supporting them. Be sure to always log battery voltage whenever possible.

11). Base fuel pressure and injector values

In order for the ECU to know how much fuel to inject, it has to be told what base fuel pressure you are running and how big the injectors are. If you are running an aftermarket AFPR, tell us what pressure it's adjusted to. If you don't know what size your injectors are, find out.

12). Properly calibrated and configured wideband sensor

If you are trying to tune without a wideband sensor, you might as well be tuning blind. This is a critical part of a proper tuning system. This sensor is one that needs to be properly calibrated (if applicable) and configured inside your tuning software to have the logged input match what is displaying on your gauge. Please make sure both of these tasks are taken care of before you start tuning.

13). Type of fuel

This is often over-looked, but with all the alcohol blends these days, it's important to know what type of fuel you are really flowing through your injectors. Unless you know for a fact that you are running pure gasoline, it wouldn't hurt to pick up a cheap ethanol tester and check what comes out of the pump every now and then. At the very least, be sure to mention what type of fuel was used for the log in question.

14). ECMlink how-to videos

If you are asking for ECMlink advice, we would expect you to have reviewed (at least twice) all of the how-to videos on this page, as well as replicated the steps on your own car.




*****

You take care of those ^, and we'll do our best to help you with what's going on inside the ECU. ;)
 
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