Suspect Turbo How do i test ?

citroenbx · Post by **citroenbx** » 23 Dec 2005, 00:23

Purchased a ZX - 1.9TD this October. Done a Full Service with Belts.
Is there an in car test i can do to confirm the Turbo is working.The reason i ask,when you ask the car to go, there is a slow build in speed and it seems your waiting around a while not exactly Turbo performance.

Should i be able to hear the Turbo spinning and should there be a rapid burst of pull when i ask the car to go ?

No pressure testing equipment here just wondered if there was a DIY test i could do to confirm the thing is spinning and the valve and boost are working.

Many Thanks

DoubleChevron · Post by **DoubleChevron** » 23 Dec 2005, 01:45

Hook a pressure guage upto the inlet manifold and take it for a spin... It should show positive manifold pressure when on boost. (I'm not sure of the exact pressure for a BX).

seeya,
Shane L.

Post by **RichardW** » 23 Dec 2005, 09:08

If you think a ZX TD turbo is not working, then chances are it's not! It should take off like a scalded cat as the turbo comes on boost at 2.5k rpm. Most likely cause of loss of performance is a spilt in one of the hoses, particularly the small one that runs from the intercooler to the injection pump.

mezuk04 · Post by **mezuk04** » 23 Dec 2005, 09:33

Yes you will certainly be able to tell if its working or not!

jeremy · Post by **jeremy** » 23 Dec 2005, 09:47

I agree with Richard. There is a thin pipe going from the pressure side of the induction (after the turbo) to the injection pump. Its purpose is to communicate the boost pressure to the extra fuel device on the pump - and so without it the engine functions broadly as a non-turbo.

You should feel a considerable acceleration as the turbo begins to work - in any gear, more so out of first when it all happens a bit quickly.

Throttle must be adjusted properly (Fully open with pedal on floor - not overtight or the clip will fall off the pedal end of the cable or the pump bearings will be strained and leak.)

You will see from posts on this board that the turbo's themselves give few problems. Its possible that a high pressure hose has dropped off (happened to me after I had the injectors changed) but this is obvious on inspection.

G4EIY · Post by **G4EIY** » 23 Dec 2005, 10:05

Hi,
A quick static test to indicate if a turbo is producing any pressure:

1.Engine on tick over speed.
2.Bonnet open.
3.Squeeze the rubber pipe that goes from the turbo out let to the induction manifold (on the left hand side of the inter cooler) with one hand.
4. Gently increase the engine revs, using the throttle lever on top of the pump.
5. Pressure should then be felt with hand on the pipe.

Cheers

yangreen · Post by **yangreen** » 23 Dec 2005, 11:28

If you get a whoosh rather than a whistle, there's a pipe problem. Happened on my 306 DT after it went back to the main stealer for some warranty work. They wanted to charge me £40 to sort out a problem they caused!

So I went back home and got the pipe back on myself. Not easy as the turbo is stuck down the back of the engine but better than giving £40 to a bunch of clowns to do it.

At the risk of teaching grannie to suck eggs, it is definitely a Turbo model?

(runs away to hide!)

Post by **Peter.N.** » 23 Dec 2005, 12:58

Just an addition to G4EIYs comments. the engine will only produce appreciable boost when it is accelerating as when it reaches a constant speed with no load, the throttle will close, so thats when you should feel most pressure. G0HET

mpr1956 · Post by **mpr1956** » 24 Dec 2005, 21:52

Hi there, A proven (and commonly used!) method of lowering smoke levels to get this engine to pass the smoke test, is winding out the fuel pump power adjustment screw slightly... this of course also has the effect of reducing the exhaust gas pressure on full acceleration, hence the turbo will not spin up properly and so on.. I too was wondering why my td xant would not perform as it should till I got round to checking this. Once I had this screw adjusted back up then the whistle is quite prominent as the revs rise past 2000.

AndersDK · Post by **AndersDK** » 25 Dec 2005, 12:00

Read this discussion for any ideas :
http://citroenz.com/forum/viewtopic.php?t=1822

citroenbx · Post by **citroenbx** » 01 Jan 2006, 18:07

Thanks Everyone starting work on the car this Thursday.so i'll keep you posted.