ZX 16v - NO POWER!!! please help

benj · Post by **benj** » 14 Jul 2003, 19:40

hello, i own a 1993 white 16v in buetiful condition, i love it the handling is superb.
the car has been off the road for about 6 months now,
the problem started when i noticed a decrease in performance, not drastic but to about 2 litre mondeo standard, i drove like this for a couple thousand miles keep on meaning to get it fixed.
one day i was having a look under the bonnet, and i noticed that one of the vacum diaphrams for the varaible inlet tract had snapped off! well that was great, solved it i thought, i was having a look at the opposite side and it snapped in my hands, now the performace went to pot, it was like a deseil, i dorve it like this for another couple thousand miles, i know i know this is very bad, but im just far to busy sometimes, well i bought two new diaphragms from citroen, fitted them
and well nothing, they open correctly like specified in the haynes, but nothing, i dorve it like that for about a thousand miles before off roading it.
ive spoken to some one who thinks it maybe the cat which has collapsed and restricting exhaust gases,
the car starts fine no problem, revs without missfire, right to the redline, no smoke, compression is correct and iv taken it to the dealers who say the ecu is showing no faults,
to give you an idea on uphill motorway slogs top speed is reduced to 75, in fourth!
i really want to fix this car but patience is not one of my virtues and i would really apprecate any help you folks can give me.
please excuse my terrible spelling
thanks

benj · Post by **benj** » 14 Jul 2003, 21:08

there are a few reads here, but no replies, come on guys, your my last hope

alexx · Post by **alexx** » 15 Jul 2003, 00:21

Sorry, I don't have a clue.
A silly question - are you sure you fitted them correctly, so that they are opening and not closing?

CITMAN · Post by **CITMAN** » 15 Jul 2003, 00:42

the only thing I can think off is to take the pipe from the engine to cat off and see if this solves your problem.

alan s · Post by **alan s** » 15 Jul 2003, 03:07

I'll run through some basic & what may appear to be silly suggestions; you'll just have to trust me that I'm doing these for a reason.
Firstly, disconnect the battery & leave it disconnected for a minimum of a half an hour. Disconnect the - terminal first, then the + To reconnect do the + first then the -
Whilst that is disconnected, check over the entire intake system for air leaks. If necessary use a WD type spray or any foam on gaskets or anything that could have slight leaks in them. Using the spray causes them to whistle & hiss if a sucking type leak is present. Be 100% sure any parts you've fitted have been fitted correctly & not back to front or anything similar; in other words, go back over everything that you've done. Also, check the air filter element to make sure the air cleaner isn't choked.
If you have the wherewithall to do it, grab a piece of exhaust pipe the same diameter as the pipe to & from the cat & fit this in where the cat fits; there is a possibility that a bit of stuffing around will be required so as to fit the Lambda sensor onto the pipe (I'm not sure the set up on a ZX)
Check the fuel filter for free flowing; when was it last replaced?
Once all the above checks have been done, take the car for a test drive & let us know what the result was.
Alan S

wheeler · Post by **wheeler** » 15 Jul 2003, 04:18

don't you have to set up those ACAV manifolds ??? not sure myself but i think the butterflys for the vairabe track may require setting up.if you think the cat is suspect just give it a run with the cat loosened off.have you been underneath & gave the cat a thump to see if the insides are rattling about ?

adrianeaton · Post by **adrianeaton** » 15 Jul 2003, 19:11

.....and if all else fails, let us know where you're based so we can recommend a friendly garage that should be able to find the cause.
With ref. to Alan's point about the lamda probe - this is in the downpipe from memory of our old Furio, and the cat is a bolt in part. You can probably pick up a completely illegal 'de-cat' pipe if you're not much cop with welding - the fittings are flange bolted too so a sleeve won't necessarily work.
The cat is a possibility - this happened on a mate's 1.8 Mondeo. Eventually the remains fired out of the exhaust and he had all his power back all of a sudden!
Cheers
Adrian

tecw1979 · Post by **tecw1979** » 15 Jul 2003, 23:10

hey this may sound silly but if yr car revs fine starts fine and sounds good with no leeks or lack of fuel and no fault codes... u tried the clutch or box???! ps i dont suppose u have any under bonnet pics? im tring to fit an mi16 lump in my zx... need help with the wiring spesificly need info on the round plug in the ruse tray that goes through the wing of the car. thanx

benj · Post by **benj** » 16 Jul 2003, 16:07

thanks for your help guys,,
yep my first port of call was to change the fuel filter, althought the old one was old and had restricted flow, new one has made no difference.
im going to weld a section in where the cat sits, see if it is that. iv tried the ECU thing before, but hasnt worked, what i really would like to do is to stick an ecu from another 16v on to see if it is that which has gone, although its not showing any faults on a reader, is there anybody with a 16v in the north west? im in chester
clutch is fine box is fine and the brakes arent binding. its got to be cat or ecu, bottom end compression is ok, havent tried top end but its running to smooth for it to be possible to have top end problems.
anyone know anything about the fuel delivery on the 16v? may it be the fuel pump? how can i test fuel pressure? wouldnt this show on the ecu reader?
tecw, i can send you as many pictures you like, what is your email address give me a couple of days to take and process them.
if i dont get the car fixed il sell it as it is
1993 K reg White 3 door 16v
every mot from new, 100k loads of service history, previous owner had it 7 years and was a copper, so wasnt thrashed iv had it 14 months now. you all know what one is how they look and perform, you know the problem with mine, any offers?
incidently go to autotrader do a national search on them i gurantee you wont see on for less than a grand, some going up to three or four, this model has to be the most valuble
t out of the 1993 Citroen range??

benj · Post by **benj** » 16 Jul 2003, 19:19

isnt there anyone interested in this car?
scrap?

VisaGTi16v · Post by **VisaGTi16v** » 16 Jul 2003, 19:27

cant help you with the problems im afraid but i have a query to you. In the haynes manual it says those diaphrams open up at 1800 and shut at 5000(i think), mine shut at 5000 ok but they open the moment revs pickup, ie around 1000 which I think is why mines so jumpy in traffic at low revs as its getting too much air in. Dont know what to do really, the haynes goes on about some valve in there but there are so many sensors, map one etc....

benj · Post by **benj** » 16 Jul 2003, 19:57

yea, mine opened just above idle too, pain in the ass as i have an uprated clutch that would stall if you tried slipping it from start so you had to raise the revs and it became a pain trying not to spin the wheels like a kev every where i went.
they work from the vacuum system and manifold pressure, if you have have something increasing the pressure they will open earlier.
mine worked differently when i put on an induction kit.
they only thing you can manually adjust is the amount they open/close by adjusting the length of the rod, i dont think you can adjust at what revs they open without sorting out the vacuum system, the ecu is programmed to add more fuel betwwen these rev ranges independtly of of the diaphrams and buterfly valves, so if they are not working in harmony like citroen wanted to , ul get effects like the one you have
the only suggestion i have is to take all the intake off, you l see the butterfly valves then,then clean it all get new vacuum pipes and new diaphrams (not cheap at 60 squid a pair) providing everythings standard it should fix it
please note i have no technical back up of all iv said just knowledge iv gained by working on the car, so if anyone wants to correct me your free to do so

glenview09 · Post by **glenview09** » 30 Jul 2003, 13:43

I had a similar problem with my 1993 16V, self serviced and did not know that there was a fuel filter under the car until too late, deterioration of power and eventual misfire, found that central 2 injectors were blocked with rubbish once the fuel canister had failed/ bypassed.
Cleaned the injectors out and more power again, good for at least 110 mph.
Car on sale on E bay this week (2425937763), rear susp bushing gone - love it but its getting old.
The ACAVs on mine broke regularly and I have given up fixing them, don't think it is a problem if you keep the butterfly in the open position.
DW

benj · Post by **benj** » 30 Jul 2003, 13:58

thanks mate!
iv jsut got the head off miune thinking it may be the gasket, but that seemed ok. at least i can put a new one in now with a new cambelt.
any one have any ideas on how to clean my injectors? soak them in petrol?
cheers
Ben

wheeler · Post by **wheeler** » 01 Aug 2003, 09:30

injectors for a petrol car are cleaned using an ultrasonic bath vibrating at a very high frequency.very similar to the one a jewler uses to clean jewelery.