2003 Renault trafic 1.9 f9q

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2003 Renault trafic 1.9 f9q

Postby Neilcur » Fri Mar 22, 2013 12:20 pm

Hi,

Got a trafic van here with intermittent non start hot and cold. Van has just had 4 injectors but hasn't fixed the fault.

It's like theres air in system or fuel running back so i decided to capture the frp sensor and see what is happening.

I have attach a good start then WOT then idle then ign off and one where van wouldn't start just cranking then ign off, but from looking at non start capture voltage with koeo the voltage goes straight to 1.1v instead of 0.5v why would this happen?

Thanks Neil
FRP trafic non start.psdata
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FRP trafic good start.psdata
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Re: 2003 Renault trafic 1.9 f9q

Postby KimAndersen » Fri Mar 22, 2013 2:30 pm

Hi
Do you have any diagnostic trouble codes ?

To start backwards with your so called good common rail pressure - I think there is a issue with way the ECU shut down on.
The pressure in the rail should come back to the same pressure with KOEO, but as you can see - the ECU and thereby DRV are shut down, before the pressure return to 0 Bar (0.5 volt) - why it happens I don´t know.

If my theory is correct there is still pressure in the rail, when you start the engine - that could explain why at no start the pressure sensor indicate a voltage at 1.1 volt.

CommonRail_Decay_Pressure.jpg

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Kim
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Re: 2003 Renault trafic 1.9 f9q

Postby Neilcur » Fri Mar 22, 2013 2:37 pm

Hi,

Thanks for replying i'll try scoping all 3 wires and see if anything strange is happening on the other 2 when it won't start.

Robski wrote:Question reversed........ why would you think it would happen ?
I know one thing i would be doing when it showed 1.1V KOEO !! & then after
looking at non start capture voltage with koeo the voltage goes straight to 1.1v instead of 0.5v why would this happen?


Question reversed........ why would you think it would happen ?
I know one thing i would be doing when it showed 1.1V KOEO !! & then after :wink:


My thinking would be there is still pressure in the rail as the voltage has increased but the 'good' capture was taken straight after i captured the 'bad' capture so the fuel must of returned to tank or there is a problem in sensor circuit? I'm not sure though so thought i would ask the question.

Neil
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Re: 2003 Renault trafic 1.9 f9q

Postby AuthorMike » Fri Mar 22, 2013 2:46 pm

Off topic what's happening with this forum again for posts to be arse about face :?:[/quote]

Witnessed it myself this time... frustrating...
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Re: 2003 Renault trafic 1.9 f9q

Postby Robski » Fri Mar 22, 2013 3:16 pm

looking at non start capture voltage with koeo the voltage goes straight to 1.1v instead of 0.5v why would this happen?


Question reversed........ why would you think it would happen ?
I know one thing i would be doing when it showed 1.1V KOEO !! & then after :wink:
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Re: 2003 Renault trafic 1.9 f9q

Postby Neilcur » Fri Mar 22, 2013 3:21 pm

Hi,

Scoped all 3 wire this time and capture is below.

van is a 2003 and there is no fault codes but i haven't had a good quality scanner on it.

In the capture the van has a long crank time then starts but has no throttle respone then shortly after throttle returns for a wot then back to idle to stabilise then ign off.

There is a .2v difference when van first starts but won't rev and after wot what does this convert to in bar?

Would in be right in thinking i need to look at the fuel rail PRV and return system to tank?

Thanks Neil
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traficfrplongcrankthenstart.psdata
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Last edited by Neilcur on Fri Mar 22, 2013 3:47 pm, edited 1 time in total.
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Re: 2003 Renault trafic 1.9 f9q

Postby AuthorMike » Fri Mar 22, 2013 3:25 pm

HI - Wherever this post appears PLEASE note that the clocks on the servers had fallen out of sync, so possibly for the next 30 minutes posts will appear before ones that were made earlier today.. Very confusing and I can only apologise...
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Re: 2003 Renault trafic 1.9 f9q

Postby AuthorMike » Fri Mar 22, 2013 3:29 pm

I have overlaid the two waveforms using the reference waveform feature, and it shows the differences quite nicely. Here are my observations (I am no expert, still learning myself), sadly they are not fixes for you...

FRP traffic.jpg


I believe 0.5 V indicates 0 bar pressure on FRP sensors. As there are no triggers used on your traces I assume you are starting the scope, then around 5 seconds later you are attempting to start the van right?

On the good trace, the FPR sits at 0.5V, 0 bar pressure for 5 seconds (I guess with koeo) before steadying at 1.3 V once idling, before you completed the WOT test. The bad trace seems to jump straight to a slighlty lower idle voltage, around 1.2 V (I know the van did not start)...

What I can't work out is why the van is not starting. If it was struggling to hold pressure your WOT test would not reach the 4.5 V (circa 1600 bar)....so I would perhaps suggest the sensor is OK.

I am sure someone with more knowledge than I can shed some light,...

The obvious questions I guess, have you checked for vacuum leaks? Also, it may be worth checking and/or scoping the other wires to the sensor?

I did a quick google search, is it a 52 plate?

http://www.bba-reman.com/forums/Topic76145.aspx

Edit: Just re-read, if its key on engine off, then the non start sensor shouldn't have any voltage above 0.5V !?
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Re: 2003 Renault trafic 1.9 f9q

Postby Robski » Fri Mar 22, 2013 3:47 pm

My thinking would be there is still pressure in the rail as the voltage has increased but the 'good' capture was taken straight after i captured the 'bad' capture so the fuel must of returned to tank or there is a problem in sensor circuit? I'm not sure though so thought i would ask the question.


Answered it yourself there so go test ..............

Off topic what's happening with this forum again for posts to be arse about face :?:
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Re: 2003 Renault trafic 1.9 f9q

Postby Neilcur » Sat Mar 23, 2013 11:41 am

Hi

Will get back to this on monday.

The snow here is up to your knees so called it a day and got home.

Think i need to look at prv on end of rail and see whats happening and check wiring from sensor back to loom.
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