Polo problem noobie here

[Dan_uk]

Hi guys I got a Polo 1.3 genesis, I know its not a G40 but i thought you guys may be able to help.  The car must of been sat for a year or two when I bought from a dealer.  In the car history it had recently had the brakes done as they were seized, engine bay was full of rotten leaves the usual.  So I bought it for £350 year TnT 86k on the clock apart from leaves its mint.  The car lasted 2 weeks, took me and the family on a 300 mile round trip and was fine.  The the other day I finished work got 100 yards down the road and the world disappeared in a plume of steam from the exhaust 

  So I presume its the head ( as I owned a R5 gt turbo for a few years I know all about heads going!) So straight away I start stripping it down head looks ok gasket hard to tell as it pretty much fell apart as I seperated the head form the block. Anyhow got it all back together now had to replace the water pump as that was seized solid (not mechanically) just the casing, so I couldnt adjust timing belt.  So new water pump new oil filter new head gasket.  All back together now,  my problems are now it has very lumpy tick over revs go up and down "hunting" is what my boss called it.  Car sounds good when its reving 2k plus, just when you easy off the pedal it dies.  I tried driving round the block to see if a little run would clear the problem, this didnt go to well as the car kept constantly dying.  It would pull off fine then lose power then pick up again and then die off.  Had more steam coming out the exshaust by the time i got home.  I never touched the timing (dizzy side) the actual timing belt is bang on where it should be.  Took the plugs out to have a look they were very black and sooty so could this be some sort of fuel flow problem?  Why all the steam? Do I need one of them Crypto tune things done to it? Any help much appreicated.

Dan

[hayesey]

checking the ignition timing would be my first port of call.

Is it still using water then?  Or is the steam just from water in the exhaust from last time it went (only takes a tiny amount of water in there to make a lot of steam).  Did you replace the head bolts when you did the gasket?  Also did you check the head for flatness and/or get it skimmed when it was off?

[Dan_uk]

I didnt get the head skimmed it prolly should of but it seemed pretty true.  Im not sure if any water is being used yet as I imagine its going to take a while for the levels to settle down.  Forgot to say that the oil pressure light comes on and beeps at me after a while, on checking the oil level i am just below the max bit i put in cheap semi synthetic 10 -40 w oil.  Cheers for reply.  Whats this about the Blue sender unit, that might be worth a try I was getting about 31mpg out of it before i did the head gasket.

[hayesey]

oil light could be that the pressure sensor wires (yellow and blue ones on the head) are connected the wrong way round.

[Dan_uk]

Right after alot of tinkering Im stuck on the engine hunting,  the steam from the exhaust has stopped  so my head work must of been ok.  I have replaced the timing sensor in the dizzy along with a new rotor arm and dizzy cap.  When the engine starts its 500 -1000 rpm up and down constantly if i touch the pedal i can sometimes get it to rev most times it just dies.  I havent replaced the blue sensor on the thermostat housing is this worth doing?

  Ive cleaned out the breather hoses the amount of crap that came out of them! sheesh, but it still didnt help the running of things.
  Reading the Haynes book of lies it says something about the ECU storing faults until its plugged into a VW computer.  Is there a way of clearing these without a VW computer?

  I've not got a strobe gun am I'm a bit unclear of how to use one on the Polo I think i have done it before will look in the book of lies again.  Any more ideas as to what I should do next please?

[Dan_uk]

Cam belt is defo on the O mark, I dont know what Im looking for with the Z mark is this the dizzy side of things? Car sounds pretty good at 2k plus revs wise.  I cant seem to see any adjustments on the single injection module, isnt it all done by the ECU and various sensors?

  Think I got all my vacum pipes connected

(this isnt a G40 Polo unfortunatly a mark 2.5 coupe 1993 genesis AAV engine made in Spain jobber)
  only vacum hoses that Im aware of are the ones that go onto the Airfilter box and they seem fine.

  I took out the Lambda sensor and cleaned that up man that was all black and sooty as were the plugs again.  So weighing that up with the poor economy I was doing before head gasket went pop I'm thinking maybe the Lambda needs replacing as its running super rich.  Would all the steam coming out of the eshaust killed the Lambda?

[Dan_uk]

Well I have had some sucess I disconnected the Lambda sensor and put new plugs in.  This has resulted in the car ticking over at around 600 rpm ish.  Which is a little low but it holds it quite well, still getting the oil light come on either when i am putting engine under alot of load or its just intermitent.  I never disturbed the yellow wire or the blue wire when redoing the head any ideas how to rectify this there is defo enough oil in the engine without being too much oil in there.

[hardchargin40]

Sounds like your ISV (idle stabilisation valve).  Squirt some carb cleaner through it, while revving the motor to stop it dying.  Or remove it and clean it up.

ALso as Hayesey says, make sure you've got the high and low oil pressure sensors refitted the correct way round.

[Dan_uk]

I am looking for this ISV bit where does it live in a 1.3 genesis, this car is a right pain to find info on, Haynes is very vague internet searches are normally on the GT or G40.  I went to scrappers and took a Lambda sensor off of a golf (mark 3) it think looked roughly the same as mine fitted it and its hunting again with it disconnected it just runs at 500rpm and is lumpy.

Im also noticing that if I accelerate the car makes a sucking noise and regulary dies on me does this sound like the ISV bit?
  I read a bit up on the ECU and how you can set it up, but it wasnt refering to my model of car as I dont have an idle screw anywhere come to think of it I cant adjust anything excpet for the dizzy cap.  So its all down the the ECU and its various sensors.  I have'nt changed the "blue" sensor as Im struggerling to find a supplier whats this ones real name as they wont list it as the blue one on the web site.  I've searched Euro parts but didnt really win who else do you guys use for spares?  And is there a way of resetting the ECU without going to a Vdub garage?

[vwmk3jon]

You might find the ISV under the inlet manifold. I also doubt that the lambda off the gold would be suitable for your car.

Idel screw is on the back of the throttlebody if anywhere.