any mk2 polo sniffers in here?

[steveo3002]

fitted mpi fuel inj from a mk2f into my mk2 , cant seem to get it sorted



suffers from a bad idle,bit bumpy pop pop sound and refuses to start hot - between 3-20 mins , will start with bts undone , drives fairly okay above idle 

a few things ive tried /done

timing set as per the book 
air bypass mixtured tired various settings ...its set to 14.1 afr via a wideband gauge at the moment
tried another dizzy /cap/arm
tried another coil
correct plugs fitted
earths good
tried another tps
no obvious air leaks + charcoal can deleted
correct 3 bar pump fitted
new genuine blue sender plus tried others i had laying around 
spare set of used inj tried with new o rings
spare afm tried 
blocked the isv at the tb elbow- no change in running

engine basics should be fine as ive had the car driving for 2 years on a carb ..ive not touched the internals since

has crude diagnostics , no codes showing

still waiting on a ecu to try...them im pretty much out of ideas , anyone localish to cambridge that knows these , or a garage that remembers old cars , none of the garages ive spoke to have any ideas and dont really work on old toot

[Parky]

Might be worth asking pauldoubleyou.

 

He seems to be a bit of a VW whiz, have a look at his 20v engine into a Lupo thread

[4wheeledstool]

Might be worth testing the wires from the temp sender to the ecu. One of my Polos displayed the same symptoms about 10 years ago - one of the pins in the blue temp sender plug was seriously corroded causing a duff signal.

[steveo3002]

Might be worth testing the wires from the temp sender to the ecu. One of my Polos displayed the same symptoms about 10 years ago - one of the pins in the blue temp sender plug was seriously corroded causing a duff signal.

 

yeah it kinda points toward it 

 

diag live data shows accurate reading from it though , and ive used the multimeter to "beep" its continuity and wiggled it and its checking out ...guess it might be worth running a new wire

 

can you describe more on what happened with yours ...im really struggling here

 

thanks

[steveo3002]

right 

 

add to the list tried spare ecu , tb and fpr - no change 

 

also ran fresh wires from blue sender all the way to ecu..nothing 

 

o2 sensor fitted too

[4wheeledstool]

yeah it kinda points toward it

 

diag live data shows accurate reading from it though , and ive used the multimeter to "beep" its continuity and wiggled it and its checking out ...guess it might be worth running a new wire

 

can you describe more on what happened with yours ...im really struggling here

 

 

Mine was just running over rich with a lumpy idle - to start it when hot needed the throttle wide open.

[steveo3002]

sounds similar ...no amount of pedal will get mine going when hot

[4wheeledstool]

In my case the charger provided a small amount of boost when cranked with the throttle wide open - the extra air must have helped start it?

[steveo3002]

right ..got the car beside another running gt and after scratching about we found i had continuity between the fuel rail /isv plug and ecu pin 3 (i think) and the other car didnt..turns out the fuel pump relay even though it had the correct amount of pins and the right diagram the pins werent in the same places

 

this has cured the hot start problem( i hope )

 

still idles a bit rough...engine sounds okay from the bay , but the exh tip is all pop pop putt putt

 

connecting the new bosch o2 sensor makes the idle worse , gave it a try but had to pull over and disconect it  

[vulgalour]

We've got some Mk2 Polo breadvan spares available if they're of interest/use?  Set of Ranger roof bars, pair of early rear lights (small reversing lens), and a pair of B pillar vinyl trims.

[steveo3002]

dont need any of those , thanks very much anyway

[vulgalour]

No worries.  If I find anything else I'll shout up, there might be something else hiding.

[steveo3002]

right sent the injectors away thinking it might be the cause of the rough idle

 

heard back...one is unusable , another suggests its replaced so might be onto something now 

 

was tempted to diy clean em with the aerosol and small battery as per youtube , wouldnt have proved anything so worth having em checked  

[steveo3002]

[Shirley Knott]

Can't offer any suggestions re the running issues I'm afraid, lots of experience with vag shite but this is somewhat before my time.

 

Meanwhile, do you mind me asking who you used for the injector check?

 

Currently toying with the idea of sending some of mine off to 'Injectortune' for a cleanup at present...

[steveo3002]

https://www.ebay.co.uk/p/ASNU-Petrol-Injector-Flow-Testing-Ultrasonic-Cleaning-Service/589504903?iid=302745202454&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D51875%26meid%3Df98c8885fdbd42118fde00390ae30471%26pid%3D100005%26rk%3D3%26rkt%3D12%26sd%3D380072659398%26itm%3D302745202454&_trksid=p2047675.c100005.m1851

[Shirley Knott]

Thanks for the link.

 

It sounds as though you've tracked the issue down to a FUBAR injector, but as another 'stab in the dark' do these have issues with crank position sensors? I know they can be to blame for a hard/no start condition and iffy idle on much of the VAG range and other stuff too...

[steveo3002]

no crank sensors ....yeah the inj wont be helping matters , got another set sent off so fingers crossed theyre better or i can make a set of 4 out of them

 

will report back if /when i get a good set fitted