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Disgusted
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Posted 8/3/2012 5:02:33 PM
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Group: Forum Members
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2000 Vauxhall Zafira 1.8 petrol manual X18XE1 with cable throttle and EGR
This car sometimes runs ok, sometimes kangaroos and will not idle. When the fault occurs it is running extremely rich and MAF reading is anything from 26 to 47 kg/hr at idle.
MAF earth has been earthed to the rear of the cylinder head. No voltage drop across here or to ECM case. Voltage measured across the MAF connector matches that in live data (2V at idle when the fault occurs).
I suggested replace MAF with new genuine one as I see it is reading far too high. MAF has since been replaced with a Fuel Parts one (its third) and is still the same.
I have told customer the new MAF is either incorrect for the application or faulty. Can someone please confirm I am not going mad?
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Disgusted
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Posted 8/3/2012 5:06:02 PM
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Sorry posted in wrong section, please move to Problems & Solutions.
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K And R
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Posted 8/3/2012 5:07:11 PM
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D
FOOL Part,s  Say no more.
Kev.
"If you dont KNOW how it works, don,t try to test or fix it"
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cartech
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Posted 8/3/2012 5:21:32 PM
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If it were a lower than expected reading, I would be looking elsewhere, however as its higher, either Maf, or an over voltage from alternator.
If I understood women as well as I understand cars, I'd be the envy of every man.
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Disgusted
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Posted 8/3/2012 5:26:06 PM
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Thanks for replies, battery voltage and MAF supply voltage are good at 14V.
I think if the engine was genuinely drawing that much air, it would be revving its head off, and by measuring directly at the MAF I believe I have ruled out any other issues.
Just wanted a second opinion, I'll tell him that I'll come back when its got a new genuine MAF.
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marks152152
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Posted 8/6/2012 7:57:49 AM
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What is the EGR doing at idle. What EGR pulse ratio and EGR feedback voltage do you have?
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Disgusted
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Posted 8/6/2012 9:34:39 AM
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Hi,
EGR is working correctly. MAF is reading high so doesn't point to an EGR fault. I've told him to fit a new genuine MAF so that should be the end of it.
8/6/2012 9:35:07 AM by
Disgusted
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Tismot
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Posted 8/6/2012 5:11:50 PM
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For what it's worth I think you are on the money.
One test you could do ( to confirm ) would be to cut the output from the AMM and make sure that a voltage is not on the line.
This way you could monitor the output from the AMM independently from the loom.
Mark
Modern cars, Its all wizardery and witchcraft
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