Technical Stilo 1.6 - Delayed acc pedal response...is this a injector problem?

[ivand]

Mine readings are 350mBar at idle. Only difference when looking Deckchair's graph is that at instant revving from idle to around 2500 rpm I get around 720 mBars (but I suppose this is influenced by how much fast you press the acc pedal...)

This afternoon I'll do other researches, checkings, measurings...

 

[ivand]

Yesterday I did a test for false air leakage. When I blocked air intake (with palm of my hand) the engine switched off in few seconds, without signs of leakage. But it is very hard to be sure in this, as
the intake manifold is producing also an air flow sound.
To be sure, I will ask mechanic to especially look on this before he takes probe ride.
By the way, I am convinced that there's not any air leakage 'cause it would manifest in "higher" idle... But, I don't mind extra checking. And I am also more convinced that my Stilo lacks of power :-(.

After new test for LTFT and STFT, the readings are similair to reading of
previous test:
@ idle => high negative values;
@ 1000-4000rpm => high postive values
(or look at previously posted graph)

And here are the readings of MAP sensor and engine load:
Ignition ON (engine off) = 1004 mBar;
@ idle rpm = 328-372 mBar = 7,85-9,125 kg/h
@ 1500 rpm = 310 mBar = 20 kg/h (average)
@ 2500 rpm = 271 mBar = 27 kg/h (average)
@ 3500 rpm = 230mBar = 35 kg/h (average)
(While atmospheric pressure was 1002mBar).
The following graphs were made while keeping rpm at desired value.
(Keep in mind that my right foot is not so still )



Also I clicked on Fuel system monitoring (in FES) and it resulted OK (whatever this is).
Tomorrow (hopefully) I'll be doing recalibration test with MAP.

Is it possible to test fuel pressure???

 

[ivand]

Finally:

I 've done the MAP recalibration process... Still all the same...

After that, I also took a ride without MAP to see how it would be driving my stilo without
MAP. Maybe it feels a little bit better response, but that's not it.

I have arranged a "meeting" with local FIAT service for Monday to get it checked.
Must admit that service office-man looked me pretty strange. But, let's wait for Monday to come...

Any more suggestions ???

 

[hanzs]

As was mentioned above - check the timing of cambelt.

 

[ivand]

I went to FIAT this evening and the chief mechanic took my car for a ride. He didn't find any abnormalities during ride, or loss of power or etc, but agreed that the system shows strange parameters and excessive consumption.

He adviced me to make an ECO test, before going to check cam-belt.
So I did, and the ECO test shown all the best: ( Lambda=1.010; CO=0.006% vol; CO2=15,73% vol;
HC=6 ppm vol; O2=0,23% vol; COcor=0,006% vol).
Also I talked to guy that sold me the car. He said that he did not notice any differences in ride after the belt was changed, but thinks that this consumption is abnormal. (He is 65 years old).
In this office (where the belt was changed) nobody has noticed that belt should have been replaced (by planned maintenance) 2 years earlier. Only after owner noticed that it's time for cambelt change, they did this job.

 

[ivand]

Finally, this Monday (28_11_2011) my Stilo is going to garage for cam timing check. This is third FIAT's service that I went & talked to, and I think this one will do the job right.

So, let's wait till monday to see...

 

[ivand]

Yes, the phase was out... You were right guys. Thanks.

Mechanic put 1st piston into TDC and checked cam timing with cam tools.
The intake cam simply clicked-in it's place, while the exhaust cam tool could not fit to cam...
The exhaust cam was out for 1/2 tooth - retarded. (by words of mechanic)
(This is a bit confusing to me but never mind - I'll count it as 1 tooth.)

I took a long ride, and the differences are noticeable:
- very steady idle at the dashboard
- much better response in low rev range
- much better response to acc pedal
- computer shows less consumption
- "softer" work at choke (while warming up)
- there is no strange "V-engine" sound

One thing that I would do too is to re-check system with ELM scanner. If it shows improvement in LTFT&STFT that's it!!!
As soon as I do this I ll post reply. Thaks guys.

 

[hanzs]

Finally you solved it! Congratulation!

... to find a good garage (not overpriced, with skilled mechanics) is problem everywhere...

 

[ivand]

To mention is the fact that I still can feel small vibrations on idle, maybe now they are more noticeable.
After the first readings of LTFT, STFT, MAP-pressure, it is obvious that noticeable amount of improvement is done.
I'll make graphs as soon as I can.
The new values for LTFT&STFT are now all above zero, i.e. they are all positive. And they are more "steady".
At idle arround 60%, reving up - the percentage descends to cca 35%.

That is result produced by clogged injectors I beleive. So, next step is - injector themselves...

 

[ivand]

Here are the graphs :

The graphs for LTFT&STFT at higher still revs (1500, 2500) are about 35-25%.

as you can see the value for MAP has changed too (and it's now back to normal i guess)

 

[richydraper]

looks about the right readings for the MAP sensor! You really want to be cleaning those Injectors to get your fuel trim values down though bud!

 

[ivand]

looks about the right readings for the MAP sensor! You really want to be cleaning those Injectors to get your fuel trim values down though bud!

this morning went to service and had injectors ultrasonicaly cleaned. Onboard comp shows there's some improvement in consumption, but when connected to ELM it still shows high percentage LTFT.
2. questions:
- how do I get fuel trim reset (is this possible to do with "clearing trouble codes" as I assumed)
- maybe the lambda sonde is giving wrong measurements?

thanx in advance