RhinoPower Ltd

cosave7904 · Veteran Member

RE: Suzuki Vitara 1.6 8V Fast Idle problem

yelatab · Veteran Member

Dear Katie, I am sorry to hear that your doctor made a mistake and put you on Depo injections. You say that you are still getting injections? These injections are made from progestin, a synthetic form of progesterone which is used mainly as a method of birth control for women who cannot use any other form of birth control. One of the drug’s side effects is weight gain. A single injection lasts for three months. So if you are still getting these injections, please, please, tell your doctor that you don’t want to receive them any longer. The effects of the drug will remain in your body for three months, so during these three months, it may be difficult to lose the added weight which you gained, no matter what you do. There are other more gentler ways to regulate your periods and menses, especially at your tender formative age. Here are some of the negative reasons for not using Depo-Provera: it can cause decreased bone density which can lead to osteoporosis, depression, increased blood clots, liver damage, headaches, hair loss, leg cramps, nervousness, dizziness, abdominal bloating, and weight gain. For your stretch marks on your stomach, you can rub some vitamin E on them. Just puncture a capsule of vitamin E and gently apply to your stomach area once or twice each day. The stretch marks will respond to the vitamin E if you use it regularly and use it as soon as they appear. The older the stretch marks, the longer and more difficult they are to rub away. It is best to use natural vitamin E, which can be distinguished from the synthetic form by the following small print and notations on the vitamin bottle: d- is the natural form, and dl- is the synthetic form. Use only the d- form which is the natural form. I think that synthetic substances have caused enough harm already, and should be laid to rest. Find a doctor who will listen to you, have patience until the Depo drug gets out of your system and body, and continue follow a healthy diet and exercise regimen to get back to your former weight. Please read the posts above to learn more about dieting. Good luck. 강남 풀싸롱

TechSupport · Guru

So we think we have an air/vacuum leak, maybe the ISC is faulty? the idle looks to be a bit to low for that but we can test it anyway. For this test we needed to use Rhinoview and its RPM Control. First test was to set the idle speed to 1000RPM and see if the ISC could control engine speed when a bit more air was called for:

Engine Control by diagnostics on Suzuki Vitara

We can see that the ISC flow rate increased to 45% and the ECU was able to bring idle up to the target speed and was in control so the ISC is fully functional. Just for interest I set the idle speed to 500 RPM:

Suzuki Vitara no idle control

The results from that test confirmed what we saw when using TunerPro, in fact we could probably have just done this test but I wanted to present two different approaches. We have an air/vacuum leak, we just need to locate it.

TechSupport · Guru

The scaling of the history table may look a little odd but it is scaled the same as the VE map which allows this feature to be used for tuning VE values.

TechSupport · Guru

This is a Suzuki Vitara with the 8V engine, its a 2000 model but is essentially the same as any 1991 through to 2001 Vitara. The problem is that it is idling at around 960RPM and has a hesitation coming off idle. The ECU is a 1112 type ECU and there is a comprehensive TunerPro adx definition for this model. The SDL interface was plugged in and TunerPro fired up:

Suzuki Vitara fast idle problem

The engine was warmed up for around 15 minutes, target idle was showing 800RPM but the idle was at 970RPM, 800RPM target and no CEL warning indicates that the ECU is not in a back up mode. The coolant temperature was showing fairly solid at 80C so no problems with the CTS. The O2 sensor was switching rapidly between 0V and 1V, this is unusual as it would usually show between something like 0.1V and 0.9V, the fuel trims were not moving and the rich/lean flag was indicating permanently lean, this indicates that the ECU is trying to control fuelling but cannot. IAC flow is quite low at 10l/min indicating that the ECU is trying to reduce air to bring down the idle, everything at this stage points to an air leak on the intake side.

As further test I created a history file to show fuel trims relative to RPM and Load (MAP in mBar). An air leak will have more effect at idle because there is less air flow, as the load increases so will airflow a leak will become proportionally lower. Graphing the fuel trims showed up an issue with the definition, the STFT ands LTFT values are swapped, the table below actually shows the STFT:

Suzuki STFT comparison table

The TunerPro definition outputs the decimal value for the fuel trim. 128 is equivalent to zero, below 128 means the ECU is running lean and above 128 means the ECU is running rich.

1000RPM/483 mBar is the load cell that the ECU is hitting at idle and as load increases the fuel trim returns to normal, another pointer to a vacuum leak.

One problem with using the history tables in this way is that TunerPro logs all hits- including those during fuel cut which can skew the readings, the history table is set up to average over 20 values so with OBD1 it only takes a few seconds for any spurious readings to be averaged out.