Hi, I have recently purchased a Vauxhall Astra 1.7TDI (2003) with 70,000 miles on the clock. Every now & then the car seems to misfire/judder. It does not do it on every journey, I could drive 200 miles & it may only do it 3 or 4 times. On other occasions I have driven short journeys & it has juddered several times & then cured it's self again. On other occasions it has not done it once for 4 of 5 days. There does not seem to be any one thing that makes it do it allthough it possibly seems to be worse on & after motorway driving & also when the weather is hot. I have replaced the fuel filter & put injector cleaner through it but with no luck. Does anybody have any ideas as to what it may be & what I could do the cure it.
Many thanks
Russell.
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Russell
How long does this misfire last? Just for a second, or for miles? On these engines, one common fault is cracked solder joints inside the little ECU that's bolted to the pump itself. That fault will leave [often red-herring] fault-codes in the main ECU, so maybe a code-read is the best way to go.
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I agree with screwloose above.This could be the initial stages of the pump Ecu failing. A code read may possibly give the fault of spill valve problem.The ecu is bolted tto the rear of the enine ,low down.and are usually easily repaired.(a new unit is appox £600 ).
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Thankyou for your reply Screwloose. The misfire only lasts for a second, but occasionly it will do it several times with a couple of seconds gap between each judder then cures itself. I am going to take your advice & get the codes read, do you know if the codes are read from the the ECU that's bolted to the fuel pump itself or is it just taken from the main ECU?
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Russell
The fault-codes for the diesel injection are read from the main engine ECU through the diag socket in the normal way. It's likely that this year will be CAN-networked; but most places can read them. If there's no relevant codes; a slight air leak into the diesel can't be ruled out.
As already stated, beware obscure codes caused by those failing solder joints. Whoever thought that it was a good idea to bolt fragile ECU's on to diesel engines? Profitable though... GM must sell thousands of ECU's. I've changed a few ECU and pump control relays on these too; doesn't fit the symptoms, but...
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Thankyou "Ian D" ,"elekie&a/c doctor" and "screwloose" for you replys.
I have taken my Astra to have the fault codes read today & have been informed that there are no fault codes showing. It was suggested by the garage in light of no faults showing that it could be air leaking into the diesel as was suggested by screwloose or possibly the EGR valve may need cleaning.
I am going to start by changing the seals on the fuel filter chamber. Does anyone know of anything in paticular to look for & any guidance for cleaning the EGR valve.
Many thanks
Russell.
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Russell
Also get them to check the available vacuum level from the services half of the vac pump; should be a min of 21"Hg at idle. If these run low on oil, [and some of them drink it] that expensive vacuum pump gets trashed very quickly. The crank sensor, or the aforementioned relays, might be other "no codes" possibilities.
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