No Boost at all....need help

[andyg plym]

Thats right, perhaps its a case of poor running affecting boost, rather than lack of boost causing poor running?

When did these problems first arise? after mods? all of a sudden? or has it been this way since you've had the car?

just to try and get a bit more of an understanding thats all.

Dan

had problems since i got it back after swapping to an avant for a year, the car was apparantly running fine on an rs2 turbo on the tubular manifold. when it came to me i had to put my turbo on (stock).
Its never run right with a k24 on it.I never saw it running in the rs2 turbo and have just been "told" it was running right.

[GazzaG60]

on the corrado unplugging things often was a good way to see if there was an issue. i run with no o2 probe for 12 months on that. in the end it was an earth issue. i run 1 to the mount, 1 to the battery and 1 to the earthing rings under the dash. never a problem after that.

do you have an AF gauge? if not get one as its ahrd to diagnose lambda issues without one.

try unlplugging the 02 sensor and starting her up. see what happens.

check the ISV. on VW that circuit is not fused and an issue can cause a problem in the ECU. check the main relay. what the symptoms are is a rebooting ECU that causes bad running. the telltale is the clicking from the main relay.

[bigdan]

i thought it sounded like a boost issue but if the car struggles to idle i can see it being an issue that stops it getting on boost properly

Thats right, perhaps its a case of poor running affecting boost, rather than lack of boost causing poor running?

When did these problems first arise? after mods? all of a sudden? or has it been this way since you've had the car?

just to try and get a bit more of an understanding thats all.

Dan

[GazzaG60]

i thought it sounded like a boost issue but if the car struggles to idle i can see it being an issue that stops it getting on boost properly

[andyg plym]

yes all basic stuff fine,leads,sparks etc put new boots on em too.

[AUDIS2avant]

Did you run an dv?
Many hoses work fine vhen on vacum but on boost they leak, try to disconnect all hoses and connect them again, sometimes you find cracks under the clips.
But sounds like a boost hose realated problem to me, checked th i/c for leaks?

[GazzaG60]

with the vems you have to change the polarity of the vr sensor . its one of the plugs on the bulkhead. i know you havn't had to do the change but check this. wd it. wd all the connectors there.

do same to the o2 sensor plug a little further to the turret. check its got a good connection too. have you checked the feedback is good with a meter. it may be a good probe but is the earth good? probes are pretty tough.

look above the fuses at the plastic between the window and the void below. i have a crack in mine that lets water run in a little. maybe not that but check around there anyway.

i had my manifold welded and we just did it and refitted and i had this for around 2 days where it would nt run right. cleaned the bulkhead ones and the wideband ones in my case and put them back engine side where they were originally and its been fine since.

worth a try if you have done all else. does sound lambda ish or though. is it smooth at any point? are all the plug wires and injector wires on the right places?

[andyg plym]

on a stock one at moment and is in mint condition:mischeif:

[Trist28]

If you really think its a boost leak of some kind, I had a similar thing recently too. Lots of whooshing and no boost really, ever....... Quite loud in the car. Mine has after market boost hoses and the one which connects the metal intake pipe to the throttle body was the prob. Changed back to stock and all fine. All looked fine but as the hose wall is fatter when the clip is tightened it can squeeze the hose off slightly at the base. I only found out by pulling handbrake right up tight, bonnet up and a friend listening, then rev high and drop clutch to simulate boost was obvious where noise was coming from then... Worth a look

[andyg plym]

1. bad sensor pickup from the VR. thats intermitent though if it does.
2. seal around the plastic scuttle panel gone. this means water leaks into near the fusebox. water in ambda wires for same reason. wd the full area. not on probe or in any engine bits though WD kills probes.

please explain in detail?

[andyg plym]

The new EM will NOT effect this, only more lag nothing else.
So i would be looking for maybe stuck idle control, if constantly open more air will come in back the throttle lid and effect the idle AND normal driving, but not full throttle tho.
And check wiring to tps lambda and MAF too as this is the sensors normaly that controls the idle and driving mixture.
Have you checked the plugs?

i did try another known working idle stabalisation valve and it made no difference. you can hear air being sucked in from somewhere just before the dv whooshes. i reckon its best to revert back to a standard setup.
all wiring to maf and lambda fine.

[AUDIS2avant]

The new EM will NOT effect this, only more lag nothing else.
So i would be looking for maybe stuck idle control, if constantly open more air will come in back the throttle lid and effect the idle AND normal driving, but not full throttle tho.
And check wiring to tps lambda and MAF too as this is the sensors normaly that controls the idle and driving mixture.
Have you checked the plugs?

[GazzaG60]

it should idel ok though.

even if you disconnect the pipe from turbo to IC or at the throttle bodie it should idle ok and hold. the engine is sucking after all at this stage.

i have had similar. im not 100% what it was but it was one of these

1. bad sensor pickup from the VR. thats intermitent though if it does.
2. seal around the plastic scuttle panel gone. this means water leaks into near the fusebox. water in ambda wires for same reason. wd the full area. not on probe or in any engine bits though WD kills probes.

when it did the lumpy thing id have to fight to keep it running. i believe it was affecting v in the probe.

id still expect boost from the tubular to k24. nowhere near a good balance but you gotta start somewhere.


im thinking was therer any other potentials. ill try to remember.

basically the car would run on all five but would be lumpy all the way. it wouldn't rev either. no boost due to bad running. i could set off from home and 2 minutes later it would start to stumble. this is on the vems too. i had just had my tubualar rewelded and so some wires had been moved. some were in the rain tray including my 2nd wb02 sensor plug.

[bigdan]

I think you could be right there. Maybe the tubular manifold, being of longer tract does not deliver enough exhaust gas pressure to spin up the turbine of the k24 turbo, therefore the newer turbo who's bearings are in better condition will spin up easier, and this is why you have noticed a slight gain in boost pressure? Or, as you say maybe its a dodgy ebay special!!?

Either way, if it was me, my next port of call would be to take the new manifold off and inspect it and refit the stock manifold (if you've still got it) and see if the fault persists. What have you got to loose!

hope this gets sorted for you soon!

Dan

[andyg plym]

could be summat to try, rs2 turbo was on before and apparantly was fine