Rob69
01-04-2013, 01:03 PM
Hi - re-posted this into this section today after no replies in POLO forum section, maybe more relevant to diagnostics forum!
Hi - first post for a good while and first in relation to current Polo - first petrol engine (http://www.shopzilla.co.uk/rd2?t=http%3A%2F%2Fstat.dealtime.com%2FDealFrame%2 FDealFrame.cmp%3Fbm%3D496%26BEFID%3D96425%26acode% 3D502%26code%3D502%26aon%3D%26crawler_id%3D1912009 %26dealId%3DhZoi7tf_70duUyasCd91wg%253D%253D%26sea rchID%3D%26url%3Dhttp%253A%252F%252Frover.ebay.com %252Frover%252F1%252F710-64684-24024-0%252F2%253Fipn%253Dpsmain%2526icep_item_id%253D12 1073581477%2526icep_vectorid%253D262531%2526kwid%2 53D1%2526mtid%253D635%2526crlp%253D1_262531%2526kw %253D%257Bquery%257D%2526query%253D%257Bquery%257D %2526linkin_id%253D%257Blinkin_id%257D%2526sortbid %253D%257Bbidamount%257D%2526fitem%253D12107358147 7%2526mt_id%253D635%26DealName%3Dzenoah%252Fcy%252 Ffuelie%2520petrol%2520engine%2520%2527failsafe%25 27%2520kill%2520switch%26MerchantID%3D424487%26Has Link%3Dyes%26category%3D33%26AR%3D-1%26NG%3D1%26GR%3D1%26ND%3D1%26PN%3D1%26RR%3D-1%26ST%3D%26MN%3DmsnFeed%26FPT%3DSDCF%26NDS%3D1%26 NMS%3D1%26NDP%3D1%26MRS%3D%26PD%3D0%26brnId%3D3139 %26lnkId%3D8060231%26Issdt%3D130328010152%26IsFtr% 3D0%26IsSmart%3D0%26dlprc%3D17.99%26SKU%3D12107358 1477&mid=104482&catId=13195&atom=11342&prodId=&oid=4893683878&pos=1&bId=18&bidType=0&bAmt=25e643bb8680d02f&cobrand=2&rf=af1&af_assettype_id=10&af_creative_id=6&af_id=11444) for a good while!
Car is 2005 1.4, 16V, 75PS, BKY petrol engine (http://www.shopzilla.co.uk/rd2?t=http%3A%2F%2Fstat.dealtime.com%2FDealFrame%2 FDealFrame.cmp%3Fbm%3D496%26BEFID%3D96425%26acode% 3D502%26code%3D502%26aon%3D%26crawler_id%3D1912009 %26dealId%3DhZoi7tf_70duUyasCd91wg%253D%253D%26sea rchID%3D%26url%3Dhttp%253A%252F%252Frover.ebay.com %252Frover%252F1%252F710-64684-24024-0%252F2%253Fipn%253Dpsmain%2526icep_item_id%253D12 1073581477%2526icep_vectorid%253D262531%2526kwid%2 53D1%2526mtid%253D635%2526crlp%253D1_262531%2526kw %253D%257Bquery%257D%2526query%253D%257Bquery%257D %2526linkin_id%253D%257Blinkin_id%257D%2526sortbid %253D%257Bbidamount%257D%2526fitem%253D12107358147 7%2526mt_id%253D635%26DealName%3Dzenoah%252Fcy%252 Ffuelie%2520petrol%2520engine%2520%2527failsafe%25 27%2520kill%2520switch%26MerchantID%3D424487%26Has Link%3Dyes%26category%3D33%26AR%3D-1%26NG%3D1%26GR%3D1%26ND%3D1%26PN%3D1%26RR%3D-1%26ST%3D%26MN%3DmsnFeed%26FPT%3DSDCF%26NDS%3D1%26 NMS%3D1%26NDP%3D1%26MRS%3D%26PD%3D0%26brnId%3D3139 %26lnkId%3D8060231%26Issdt%3D130328010152%26IsFtr% 3D0%26IsSmart%3D0%26dlprc%3D17.99%26SKU%3D12107358 1477&mid=104482&catId=13195&atom=11342&prodId=&oid=4893683878&pos=1&bId=18&bidType=0&bAmt=25e643bb8680d02f&cobrand=2&rf=af1&af_assettype_id=10&af_creative_id=6&af_id=11444), NON EGR. 69,000 mls. Ongoing problem is poor MPG (37-38) and lumpy idle around 6-700rpm, now that I've sorted other faults ( coil springs, brakes, water pump....) I've started to look at engine. All coil packs were changed around 15k miles ago.
Hooked it up to OBD scanner (Autel MS509), no fault codes present, but high LTFT, averaging mid +teens, STFT also tends to low +teens but occassionally dips to low -teens, during steady level road at 50-60mph. Engine temp stable at 85'C ( OBD readout, not dashboard)
Front o2 / AF sensor seems to have reasonable cross count (around 1/ sec)and reads between -0.1, +0.1mA except when open loop on engine overrun, but I'm struggling to find optimal mA range for this front sensor - maybe this mA range is too narrow / low????, sensor needs changing???)
Post cat o2 sensor (http://www.amazon.co.uk/dp/B004U0PC9A/) averages + 0.7 V and responds to throttle blips asI might expect.
I removed and cleaned MAP sensor (http://shop.ebay.co.uk/?_nkw=map+sensor) with CRC sensor spray, reinstalled it but no change to fuel trims, although car feels a bit snappier ( placebo effect maybe).
I've checked for vacuum leaks but don't suspect this to be cause as STFT & LTFT stays high even with throttle wide open and high MAP, MAP responds to throttle position. No sign of exhaust leaks. Throttle body (http://shop.ebay.co.uk/?_nkw=throttle+body) is clean as no EGR on this engine, no MAF sensor (http://shop.ebay.co.uk/?_nkw=maf+sensor) also.
I've read posts regarding Evap canister leaks but struggling to find info on the Evap system.
Can anyone offer any advice regarding high STFT, LTFT, O2 sensor (http://shop.ebay.co.uk/?_nkw=o2+sensor) optimal values (mA) and Evap system??
I'm not inclined to chuck new O2 sensor (http://shop.ebay.co.uk/?_nkw=o2+sensor) on without a bit more knowledge / justification.
Planning to do a compression test when Scottish permafrost eases off, may indicate blocked cat.
No immediate solution to this then I'll move onto sticking door locks, don't mention the aircon system.
Cheers
RobH
Hi - first post for a good while and first in relation to current Polo - first petrol engine (http://www.shopzilla.co.uk/rd2?t=http%3A%2F%2Fstat.dealtime.com%2FDealFrame%2 FDealFrame.cmp%3Fbm%3D496%26BEFID%3D96425%26acode% 3D502%26code%3D502%26aon%3D%26crawler_id%3D1912009 %26dealId%3DhZoi7tf_70duUyasCd91wg%253D%253D%26sea rchID%3D%26url%3Dhttp%253A%252F%252Frover.ebay.com %252Frover%252F1%252F710-64684-24024-0%252F2%253Fipn%253Dpsmain%2526icep_item_id%253D12 1073581477%2526icep_vectorid%253D262531%2526kwid%2 53D1%2526mtid%253D635%2526crlp%253D1_262531%2526kw %253D%257Bquery%257D%2526query%253D%257Bquery%257D %2526linkin_id%253D%257Blinkin_id%257D%2526sortbid %253D%257Bbidamount%257D%2526fitem%253D12107358147 7%2526mt_id%253D635%26DealName%3Dzenoah%252Fcy%252 Ffuelie%2520petrol%2520engine%2520%2527failsafe%25 27%2520kill%2520switch%26MerchantID%3D424487%26Has Link%3Dyes%26category%3D33%26AR%3D-1%26NG%3D1%26GR%3D1%26ND%3D1%26PN%3D1%26RR%3D-1%26ST%3D%26MN%3DmsnFeed%26FPT%3DSDCF%26NDS%3D1%26 NMS%3D1%26NDP%3D1%26MRS%3D%26PD%3D0%26brnId%3D3139 %26lnkId%3D8060231%26Issdt%3D130328010152%26IsFtr% 3D0%26IsSmart%3D0%26dlprc%3D17.99%26SKU%3D12107358 1477&mid=104482&catId=13195&atom=11342&prodId=&oid=4893683878&pos=1&bId=18&bidType=0&bAmt=25e643bb8680d02f&cobrand=2&rf=af1&af_assettype_id=10&af_creative_id=6&af_id=11444) for a good while!
Car is 2005 1.4, 16V, 75PS, BKY petrol engine (http://www.shopzilla.co.uk/rd2?t=http%3A%2F%2Fstat.dealtime.com%2FDealFrame%2 FDealFrame.cmp%3Fbm%3D496%26BEFID%3D96425%26acode% 3D502%26code%3D502%26aon%3D%26crawler_id%3D1912009 %26dealId%3DhZoi7tf_70duUyasCd91wg%253D%253D%26sea rchID%3D%26url%3Dhttp%253A%252F%252Frover.ebay.com %252Frover%252F1%252F710-64684-24024-0%252F2%253Fipn%253Dpsmain%2526icep_item_id%253D12 1073581477%2526icep_vectorid%253D262531%2526kwid%2 53D1%2526mtid%253D635%2526crlp%253D1_262531%2526kw %253D%257Bquery%257D%2526query%253D%257Bquery%257D %2526linkin_id%253D%257Blinkin_id%257D%2526sortbid %253D%257Bbidamount%257D%2526fitem%253D12107358147 7%2526mt_id%253D635%26DealName%3Dzenoah%252Fcy%252 Ffuelie%2520petrol%2520engine%2520%2527failsafe%25 27%2520kill%2520switch%26MerchantID%3D424487%26Has Link%3Dyes%26category%3D33%26AR%3D-1%26NG%3D1%26GR%3D1%26ND%3D1%26PN%3D1%26RR%3D-1%26ST%3D%26MN%3DmsnFeed%26FPT%3DSDCF%26NDS%3D1%26 NMS%3D1%26NDP%3D1%26MRS%3D%26PD%3D0%26brnId%3D3139 %26lnkId%3D8060231%26Issdt%3D130328010152%26IsFtr% 3D0%26IsSmart%3D0%26dlprc%3D17.99%26SKU%3D12107358 1477&mid=104482&catId=13195&atom=11342&prodId=&oid=4893683878&pos=1&bId=18&bidType=0&bAmt=25e643bb8680d02f&cobrand=2&rf=af1&af_assettype_id=10&af_creative_id=6&af_id=11444), NON EGR. 69,000 mls. Ongoing problem is poor MPG (37-38) and lumpy idle around 6-700rpm, now that I've sorted other faults ( coil springs, brakes, water pump....) I've started to look at engine. All coil packs were changed around 15k miles ago.
Hooked it up to OBD scanner (Autel MS509), no fault codes present, but high LTFT, averaging mid +teens, STFT also tends to low +teens but occassionally dips to low -teens, during steady level road at 50-60mph. Engine temp stable at 85'C ( OBD readout, not dashboard)
Front o2 / AF sensor seems to have reasonable cross count (around 1/ sec)and reads between -0.1, +0.1mA except when open loop on engine overrun, but I'm struggling to find optimal mA range for this front sensor - maybe this mA range is too narrow / low????, sensor needs changing???)
Post cat o2 sensor (http://www.amazon.co.uk/dp/B004U0PC9A/) averages + 0.7 V and responds to throttle blips asI might expect.
I removed and cleaned MAP sensor (http://shop.ebay.co.uk/?_nkw=map+sensor) with CRC sensor spray, reinstalled it but no change to fuel trims, although car feels a bit snappier ( placebo effect maybe).
I've checked for vacuum leaks but don't suspect this to be cause as STFT & LTFT stays high even with throttle wide open and high MAP, MAP responds to throttle position. No sign of exhaust leaks. Throttle body (http://shop.ebay.co.uk/?_nkw=throttle+body) is clean as no EGR on this engine, no MAF sensor (http://shop.ebay.co.uk/?_nkw=maf+sensor) also.
I've read posts regarding Evap canister leaks but struggling to find info on the Evap system.
Can anyone offer any advice regarding high STFT, LTFT, O2 sensor (http://shop.ebay.co.uk/?_nkw=o2+sensor) optimal values (mA) and Evap system??
I'm not inclined to chuck new O2 sensor (http://shop.ebay.co.uk/?_nkw=o2+sensor) on without a bit more knowledge / justification.
Planning to do a compression test when Scottish permafrost eases off, may indicate blocked cat.
No immediate solution to this then I'll move onto sticking door locks, don't mention the aircon system.
Cheers
RobH