Author Topic: Missing at low rpm and when accelerating - egr?  (Read 2089 times)

guest4761

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Missing at low rpm and when accelerating - egr?
« on: June 15, 2017, 01:06:58 PM »
Hello, I have a 2008 Jazz cvt 1.3 with what appeared to be an egr problem but no faults indicated on management system. I temoved the egg and blanked the apperature on the engine whilst I cleaned the egr valve with egg cleaner (soaking it overnight). With just the blank in place the engine still 'missed' at around 1900 rpm and sometimes if I tried to accelerate away from stationary. I replaced cleaned egr, still the same. I purchased a used egr and cleaned it before refitting - still same problem. I have now disconnected plug from egr and am running with engine mgt light on. Don't know what to do next. Is it the spark plugs or fuel filter? Mileage done is 50K can anyone please advise??

guest1372

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Re: Missing at low rpm and when accelerating - egr?
« Reply #1 on: June 15, 2017, 05:59:40 PM »
I think EGR valves have a worse reputation than warranted, maybe early ones from another manufacturer gave them some notoriety.  It seems you have ruled out the valve as the cause of your symptoms, I would also rule out fuel filter as that is usually trouble free and would not manifest itself at a particular rpm, the car has a pumped high pressure fuel circuit so varying engine demands do not cause fuel starvation.

It may be best to put the EGR valve back to operating conditions to keep the engine management happy.  With a low mileage car driven sedately, it may also pay to stretch it's legs once in a while - this will ensure all operating parts get exercised over their full range of movement and high temps are quite effective at cleaning up an engine.  Just holding a lower ratio once a month is enough. 

Plugs should have been changed on this car at some point, if not sure then that should probably be done; closely related to this are the coil packs, some have experienced issues with these - removing and visual inspection should yield clues.

Lastly some cars with an electronic throttle have developed a wiring fault, that manifests itself as lack of response between the pedal and the throttle body.  Your car is later than the majority of cars that have exhibited this fault so I fell it is less likely but nether the less as it is a temporary break in a wire the conditions that cause it are often repeatable and similar.

Most of these faults will cause a temporary fault code to be logged, although it will not illuminate the check engine light.  If you can have this read or use an OBDII code reader yourself then it may be easier to resolve this.
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TG

culzean

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Re: Missing at low rpm and when accelerating - egr?
« Reply #2 on: June 16, 2017, 08:26:49 AM »
The two cheapest / quickest options are new spark plugs (the rear plugs often do not get changed because garages do not know they are there,  and not changing the plugs can cause coil pack to fail)  and a good overdose of Redex (put 500 ml in a tank of fuel it certainly won't do any harm).
Some people will only consider you an expert if they agree with your point of view or advice,  when you give them advice they don't like they consider you an idiot

guest4761

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Re: Missing at low rpm and when accelerating - egr?
« Reply #3 on: June 21, 2017, 04:33:13 PM »
Changed plugs (50000 miles) and problem solved. Also had CVT 7 transmission oil changed and car is running as new, it is surprising how engine performance deteriorates and one accepts this decline. Reconnected EGR plug to remove engine management fault light and as good as new. Thank you the advice guys, I appreciate it.

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