Light load surge

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Light load surge

Postby huddie » Tue Jan 27, 2015 4:24 pm

Hi All, I am new to this forum and I am looking at Pico kit to allow me to continue fixing all possible problems myself.
The title in the subject line is the best description I can give of my current problem. The vehicle is a Citroen Berlingo Mk2 2.0HDI registered in December 2003.
The problem occurred mainly in 5th when there was very little throttle i.e. cruising along. A little acceleration would make the surging go away.
The only thing I have done is to remove all the slack in the throttle cable which goes to a throttle position sensor. This has made it a lot better but not eradicated it completely.
Hope someone can point me in the right direction.
Regards Huddie
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Re: Light load surge

Postby Robski » Tue Jan 27, 2015 5:05 pm

what do you plan to do with a scope ?

Judging by your first post, do you think it plugs in the DLC ?

EOBD compliency is usually 2001> for petrol & 2004> for diesel.

If you haven't already get a scan done of the PCM (Citroen specific) & see what DTC's are there & relevant, clear & re-scan after the fault occurs.

One piece of advice, unless you're trained don't touch the HP side of the fuel system !
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Re: Light load surge

Postby huddie » Wed Jan 28, 2015 9:41 am

Thanks for the reply Robski, I am assuming that the scope would give me real time data as opposed to just stored diagnostic codes if I used a code reader. At this point in time I don't know how where to connect the scope. The thinking is should I buy a decent code reader or should I put this money towards something better i.e. an entry level scope. You have used a couple of TLA's. What are they? Well aware of the dangers of high pressure fuel systems.
Regards Huddie
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Re: Light load surge

Postby Robski » Wed Jan 28, 2015 11:33 am

a scope will give you real time data, but sometimes this has to run along side live data (processed data) for comparison.

My first port of call with a decent scanner would be code read, note & clear, live data check/graph whilst the surge occurs.From then on I would devise a test plan for anomalies found.

DLC = data link connector
DTC =diagnostic trouble code
PCM = powertrain control module
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Re: Light load surge

Postby sigoaprendiendo » Fri Jan 30, 2015 7:59 pm

Hi there

Once you get a decent scanner, try to use the Freeze frame data, this capability is very useful for intermittent glitches

Kind regards

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