Hi fellow dubbers looking for some advice on here I have a 16v abf and basically it will start up fine first start say if it's proper cold outside the revs will bounce up and down abit from cold and then level out once it's idled for abit but say if I go to fill the car up when it's up to temp and come back and start the car it will either start up fine no problems or struggle a little to start then the Rev hang comes in and I get really bad MPG (can't get more than 20mpg) sometimes it will idle around 1100 rpm or sometimes even higher but if I stop and turn the car off and back on the revs will shoot up to about 1600rpm and drops it's idle to 900 and gets normal MPG figures So far I've replaced: ISV brand new from OEM&More, Throttle body, DIY throttle closed switch, Coolant temp sensor, Checked wiring going to temp sensor and the back of the inlet manifold, ECU, Intake air temp sensor, Fuel pressure regulator, Vac pipes, PCV valve, Distributor Cap and Rotor and spark plugs probably missed some other stuff I've replaced aswell I'm super lost on what it could be that's causing this issue have I missed a procedure like calibrating something in vagcom after replacing all this stuff? Thanks in advance if I ever get to the bottom of this
any faults in vagcom? check ecu measuring blocks also will show your sensor inputs in real time. look at coolant temp for a start lambda may be going bad, can check the values in vagcom or quick and dirty test unplug it and see if it runs much better. if it does, chances are lambda is stuffed. buy new bosch
Thanks for the quick reply I've only scanned with a cheap scanner no codes my mate has vag com I've asked if he could plug it in for me and I will let you know I replaced the temp sensor with a brand new bosch one would the values be the exact same as the dash reading or will it be a little higher due to being in the head? How would I know correct values of a lambda sensor and is there anything to look out for when checking ecu measuring blocks?
the ecu and dash senders should read roughly the same yep. have a read: https://drive.google.com/file/d/0B_V9-6xfgGlITXpkOWVpVzQ0UTg/view?usp=sharing
Cool ok I will check them this weekend and get back to you I will be happy if it turns out it's lambda will be an easy fix also I don't really understand that document how would I do it without any of the VW equipment?
your man with vagcom should be able to follow it. its same procedure just have to go into ecu, then click measuring blocks, then find the lambda block
if he hasnt already got them, heres ABF ecu label files, makes life easier: https://clubgti.com/forums/index.php?threads/vag-com-abf-digifant-label-files.199583/
Thanks for the info mate will get it scanned this Saturday hopefully and with them files it won't let me download them with me being a new member still do I need them to see all the values or will vagcom still work without them? Sorry I'm abit of a noob when it comes to diagnostics I've only used them cheap scanners never used vagcom so don't know what it's capable of doing
just need a couple more posts. cvagcom still works perfectly well without it they're just nice readable labels for the displays so its easier to figure out what you're looking at. but if you know what you're doing its no problem as the values will be pretty obvious as you scan thru
Ok no worries will try to post some more stuff on here me and my friend got abit behind today on the car so getting it plugged in tomorrow now see whether we can see anything causing my issue
So got my car plugged in on VCDS had some codes stored on ecu coolant temp sensor hall senser but cleared them and haven't come back since I've unplugged lambda and it's running exactly the same as with lambda plugged in could this mean it's faulty?
if unplugging the lambda doesnt help the issue is probably elsewhere. did you check through all the ecu measuring blocks to make sure everything was reading belivable values, especially when it was running poorly
Alright no worries I've ordered a new 16v abf lambda from oem&more as I have an 8v lambda on atm and on VCDS I couldn't tell which measuring blocks to check and didn't know what I was really looking at tbf
