Diagnostic software readings

[Zoltan]

A couple of days ago I failed the swedish MOT because of the emissions (HC = >1000ppm) Yesterday I hooked up my old computer (it didn't connect to my laptop) to the cerb and got these diagnostic values during idle. What do you guys make of it? The lambda values are fluctuating greatly between 0-1 as you probbably see on the log screen, but are within range. Maybe it doesn't fire on all the cylinders?

[marcus1970]

Had you put your foot on the throttle when the throttle pot screen was saved, it's just that your first screen reads 15.2 and the throttle pot screen reads 16.6 both on throttle 1?

MB

Edited by marcus1970 on Wednesday 4th July 15:49

[Zoltan]

I think I reved up the engine between those two pictures, but not when I actually took the picture.

[marcus1970]

In which case, it looks like throttle pot 2 maybe a bit tired. Try setting throttle pot 2 so that it reads a couple of points of a percent more. Tighten it up and see if your adaptives drop down to closer to throttle 1. If so you can tinker from there.

MB

[carl_w]

AFR 1357 bad?

[Peppe]

Hi Zoltan !

YHM

I think you have the problem in the throttle pots, both of them have logged errors. As i can see you have faultcodes on the watertemp, airtemp and barometric sensors too. Probably the car has been powerwashed in the engine bay, and water has come in to the connectors of the sensors.

This is what the software manual say about how to test the throttle pots:
Turn igninition, don´t start the engine. Press down the accelerator slowly. Throttle pot readings should be equal on both banks to within a few percent, and must not fluctuate more than 3%. The readings should increase smoothly with increasing throttle travel and remain approximately equal on both banks. If the ECU detects a fault with one of the throttle pot readings it will substitute the value from the other throttle pot, so they will both display EXACTLY THE SAME READING.

THROTTLE 1 or 2 FLT
These faults are shown if the throttle pot readings are out of range.Thottle 1 is for bank 1 (cylinders 1357), throttle 2 is for bank 2(cylinders 2468) If a fault is detected on one bank, then that input signal will be ignored, and both cylinders will be run using the "good" throttle pot signal from the other bank. The MIL lamp will be turned on.
Throttle pot faults can be caused by:
- Water ingress into throttle pot, its connector or wiring. (usually due to the use of a power washer)
- Corrosion on throttle pot connectors. (only use TVR gold plated connectors and throttle pots)
- Mechanical damage to pot or wiring.
- Throttle pot worn or "noisy"

WHEN A THROTTLE POTENTIOMETER IS REPLACED, IT MUST BE SEALED ONTO THE
THROTTLE BODY USING A SMALL AMOUNT OF SILICONE SEALANT TO PREVENT WATER
INGRESS. IT MUST THEN IMMEDIATELY BE SET CORRECTLY BEFORE THE SEALANT
SETS.


Peppe

Edited by Peppe on Wednesday 4th July 17:34

Edited by Peppe on Wednesday 4th July 17:36

Edited by Peppe on Thursday 5th July 07:05

[Zoltan]

Thanks guys! I'll check my pots.

[jbvipercerb]

As far as I know throttle pots, on a 4.2, should be around 19% so I would say both pots are low. As said before reset them, also I would clear the fault codes and see if any faults return, if the car hasn't been on the diagnostic computer for a while, and someone has power washed it or something, it may have faults stored but there are no current faults.
Also on the first screen you showed us the battery voltage is only 11 odd volts with the engine running, its nthing to do with bad running but is the alternator charging?
Keep us updated, someone else may have more ideas to help