Author Topic: 8v with intermittent issues  (Read 2669 times)

Offline g3uvn

  • Not said much yet
  • **
  • Posts: 41
8v with intermittent issues
« on: 20 February 2013, 23:06 »
I bought a 94 8V back in August for a killer price of £285, it had proof of 84k on the block but just needed a clutch, picked the car up and on the drive back found the clutch was more than adequate but needed a new cable, quids in! Did the head as it looked a bit worn, new timing belt, water pump, thermometer, tensioner and all that good stuff and it seemed to be ok, this was completed around December and I had it standing until early feb when my insurance was due.

I have since been having a few problems with the car, one of which I just cant seem to shift. The engine was hunting pretty badly on idle so I replaced the spark plugs along with a new rotor, dizzy and coil (which had been failing) and it seemed to cure that problem, then noticed it was overheating on idle so replaced the engine temp sender which did not cure the problem - however noticed it ran cold at speed and overheated at standstill so put it down to a lazy thermometer which I am due to replace.

The issue im having is that the car, once hot, does not drive at all well under 3500 revs, if you do not rev the nuts off the thing it drives like its almost got no fuel, completely limp and stuttering (slower than my 1.4 ABD) until you get to about 3500 and it feels like a turbo has cut and and thing moves like a rocket. If you give it a blast for a bit the problem goes away until you stop again and it restarts the whole process. I have a hole in the exhaust just after the CAT as someone has bodged pretty badly down their and im going to get a CAT back system hopefully end of the month, im just trying to establish whether its the lambda thats gone of maybe the MAF as im getting no codes on the VAGCOM, although it was only a cheap eBay one.

Thoughts would be really helpful on this, thanks :)

edit: also, after taking the car apart to check the vacum hoses, noticed the oil breather was pretty gunked up and cleaning with petrol revealed a split in the hard plastic part - after sealing it up and the clean the thing ran much better and the problem im having took longer to occur... I am yet to clean the TB as it looked clean already.
« Last Edit: 20 February 2013, 23:09 by CurG21 »

Offline Screech16v

  • I live here
  • *****
  • Posts: 2,432
  • MK3 20vt AGU
Re: 8v with intermittent issues
« Reply #1 on: 20 February 2013, 23:20 »
First off it seems as though your thermostat is staying open making the engine cool down as you drive  ,second your radiator fan ,does it actually come on at time of overheating,third clean the tb,check all breathers ,clean them out,replace vaccum lines with silicone 3mm id ,fix your exhaust and hopfully it will run a lot better

Offline g3uvn

  • Not said much yet
  • **
  • Posts: 41
Re: 8v with intermittent issues
« Reply #2 on: 20 February 2013, 23:52 »
First off it seems as though your thermostat is staying open making the engine cool down as you drive  ,second your radiator fan ,does it actually come on at time of overheating,third clean the tb,check all breathers ,clean them out,replace vaccum lines with silicone 3mm id ,fix your exhaust and hopfully it will run a lot better

Yeah the fan cuts in at 100C on the dash, and the switches are set at 97 - it wont go anywhere above 105 maximum so it doesnt overheat as such, but still idles hot. As for the other recommendations ill have a stab and see what i come out the other end with, just gotta wait till next week for the funds.

Offline g3uvn

  • Not said much yet
  • **
  • Posts: 41
Re: 8v with intermittent issues
« Reply #3 on: 26 February 2013, 21:59 »
Right cleaned the MAF with contact cleaner, the throttle body (was almost spotless to begin with), cleaned the ISV, replaced all vacuum hoses with 3mm ID silicone, checked all breathers and the car runs smoother but lumpy idle and loss of power between idle-3000 once warm still persists. Also nothing on vag-com still which is annoying to say the least,

Swapped to my 1.4 (which feels like a go-kart in comparison) and im gonna get together relays 30 and 167 from the scrappy, new NGK lambda, new backbox and a CAT linking pipe to fix the exhaust and replace the thermostat and refill the system. Any one got any other ideas before I look into buying a new MAF or possibly ECU if this doesnt fix the problems :\

Offline GOLF-MK3-GTI

  • I live here
  • *****
  • Posts: 969
Re: 8v with intermittent issues
« Reply #4 on: 26 February 2013, 22:09 »
Right cleaned the MAF with contact cleaner, the throttle body (was almost spotless to begin with), cleaned the ISV, replaced all vacuum hoses with 3mm ID silicone, checked all breathers and the car runs smoother but lumpy idle and loss of power between idle-3000 once warm still persists. Also nothing on vag-com still which is annoying to say the least,

Swapped to my 1.4 (which feels like a go-kart in comparison) and im gonna get together relays 30 and 167 from the scrappy, new NGK lambda, new backbox and a CAT linking pipe to fix the exhaust and replace the thermostat and refill the system. Any one got any other ideas before I look into buying a new MAF or possibly ECU if this doesnt fix the problems :\

I'm sure 8V don't have an ISV??, correct me if I'm wrong?

Offline g3uvn

  • Not said much yet
  • **
  • Posts: 41
Re: 8v with intermittent issues
« Reply #5 on: 26 February 2013, 22:19 »
Mine is pre OBD2 (1994 engine 2E) it has the ISV along the rocker cover.

Offline GOLF-MK3-GTI

  • I live here
  • *****
  • Posts: 969
Re: 8v with intermittent issues
« Reply #6 on: 26 February 2013, 22:27 »
Mine is pre OBD2 (1994 engine 2E) it has the ISV along the rocker cover.

Alright  :wink:

Offline itavaltalainen

  • I live here
  • *****
  • Posts: 2,693
  • VCDS and VCP - fault codes, coding, VIM activation
Re: 8v with intermittent issues
« Reply #7 on: 26 February 2013, 22:55 »
does the water pump run the right way round? the garage that did my cam belt put it the wrong way round too....
without a/c you can actually run the ribbed belt the wrong way round the pump pulley (wrong being the smooth side)... it should be wound round in the other way, i.e. ribs driving the water pump..

second thing.... is the ignition timing spot on? could be on very late.... heating the head up too much -> temp shooting up.
did you swap complete dizzy? is that for a 2E or AGG or ADY??  they are different, i.e. you should and can only use the one for the 2E

it should be set to 4-8 degrees before TDC @ 2-2500rpm with engine in basic setting.
with engine in "normal" mode set it to 2800 revs then accelerate it should advance to 35 to 45 degrees b.TDC
2019 Seat Leon ST FR DSG 135kW - eclipse orange - 23k miles

Offline g3uvn

  • Not said much yet
  • **
  • Posts: 41
Re: 8v with intermittent issues
« Reply #8 on: 27 February 2013, 18:27 »
does the water pump run the right way round? the garage that did my cam belt put it the wrong way round too....
without a/c you can actually run the ribbed belt the wrong way round the pump pulley (wrong being the smooth side)... it should be wound round in the other way, i.e. ribs driving the water pump..

second thing.... is the ignition timing spot on? could be on very late.... heating the head up too much -> temp shooting up.
did you swap complete dizzy? is that for a 2E or AGG or ADY??  they are different, i.e. you should and can only use the one for the 2E

it should be set to 4-8 degrees before TDC @ 2-2500rpm with engine in basic setting.
with engine in "normal" mode set it to 2800 revs then accelerate it should advance to 35 to 45 degrees b.TDC

Its funny you should say that about the cam belt but I recall when we did it back in December we got confused over the way it ran as the water pump wasn't running on the ribbed side - I will check to make sure we put it on the right way round, im pretty sure we did but I have a niggle that says we may not have. Could that cause the issues I am having then? or just the temperature related?

The timing seems to be bang on, we need to check the flywheel lines up, only changed the head of the dizzy, however the rotor after checking it last night has about 3mm play in all directions so im gonna try and get a new one lined up at the weekend. Got my uncle from the RAC coming over on the 5th so im going to get him to check it with the proper VAG-COM and check the timing out as I cant find the timing light anywhere.

Ill let you know how it goes, thanks mate for the pointers.

Offline itavaltalainen

  • I live here
  • *****
  • Posts: 2,693
  • VCDS and VCP - fault codes, coding, VIM activation
Re: 8v with intermittent issues
« Reply #9 on: 27 February 2013, 19:38 »
and as we're talking 2E... when you adjust the igntion pull off the breather pipe from rocker cover and put a screwdriver with soft end in the opening in the hose (where flow would go to the intake side of things). this needs to be air tight..
otherwise any adjustment will be crap....
2019 Seat Leon ST FR DSG 135kW - eclipse orange - 23k miles