Lethargic BX

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loudel
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Lethargic BX

Post by loudel »

Gentlemen, my BX 19 auto petrol has become just plain lazy over the last couple of weeks. It is a 1989 model with 251K kms on the clock. It revs seemingly ok but going up any incline is now at walking pace - no guts under load. On the flat it moves though less spritely than previously. Also noticed that the coolant level is down 300ml or so after 2 weeks and no obvious leak. Suspect a head gasket - what would be the symptoms?Do I now have water injection??
Thankyou all.
Loudel
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Paul296
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Re: Lethargic BX

Post by Paul296 »

If you're pushing the gas pedal and nothing much is happening, could just be that your pedal box needs welding. Is the pedal well to the right? If it is carefully bend it back - temporary fix, but if it works you'll know what's wrong. Assuming the pedal box is the same on an auto as a manual - is it?
loudel
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Re: Lethargic BX

Post by loudel »

Pedal box seems ok, have driven a friends amonth ago and did not remark any difference.
I have had the car for a few weeks, relieving it from the wrecker's yard and attempting to give it another chance in life.It certainly merits it - it is just a great driving car. Have done 1300kms since mid April and noticed that when climbing steeper grades it seemed to lack torque. But as of a few days ago it just is gutless.I note that when accelerator pedal is pushed when going up hil there is no increase in engine speed above say 2000rpm.Then as soon as the incline flattens out the car jumps into second at about 20kmh. The yellow engine light comes on more often. Had a word to a fellow up the road who has some knowledge of the gearbox and he suggests an o ring in/near the torque converter that may not be allowing fluid under pressure to pass, or perhaps a friction plate needs doing (I am a novice in auto g/box matters). The auto fluid is not black, but not red either. Could be an auto box problem after all. Any other ideas from brains trust?
Loudel
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Re: Lethargic BX

Post by citronut »

firstly get an assistant to press the pedal hard to the floor boards whilst you observe the throttle lever on the pump is moving to the end of its travel/to the throttle stop,

and yes the auto pedal box differs by only having two pedals #-o :roll: :wink:,

i might have one somewhere in my clutter

if id does turn out to be a gear box issue its not a hard job the convert it to manual

regards malcolm
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Tim Leech
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Re: Lethargic BX

Post by Tim Leech »

Have you tried changing down the gearbox manually i e moving down to 2 or 3 and then pressing the pedal hard?
Lots of Motors, mostly semi broken....
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Way2go
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Re: Lethargic BX

Post by Way2go »

loudel wrote:The auto fluid is not black, but not red either. Could be an auto box problem after all.
The transmission fluid should be clear in colour so yours is likely OK. It is very important to use Dexron2 only and not Dexron3 as 3 is not a replacement for 2 and will shorten the life of the box!
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Re: Lethargic BX

Post by Way2go »

loudel wrote:I note that when accelerator pedal is pushed when going up hil there is no increase in engine speed above say 2000rpm.Then as soon as the incline flattens out the car jumps into second at about 20kmh.
The auto won't up-change if the car is struggling and it is below what seem to be pre-set change speeds.

You don't say whether you have a carb or injection but if there is a second butterfly in the throttle block this may be faulty or sticking effectively strangling the engine.

PS: You will find what I mean about preset change speeds on this box for example on 3rd to 4th on the flat- It will change up to 4th at 42mph but drop back to 3rd at 38mph!
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Stuarted
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Re: Lethargic BX

Post by Stuarted »

My manual BX 1.9 diesel suddenly became very lethargic.

Was simply lack of throttle due to worn linkage. Fixed linkage = instant total cure.
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michaelr
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Re: Lethargic BX

Post by michaelr »

A bit of an update on Loudel's "lethargic" BX. I spent a bit of time at his place looking at a few things.

The car is a BX19TRi automatic so has the injected 1.9 with a Motronic system. It was really lacking in power but an exhaust analysis showed the air/fuel ration to be fine.

Suspecting the catalytic converter Lou removed the exhaust system and it does indeed look like the Cat is blocked. Maybe the reason the exhaust gasket on the manifold was blowing was because of this and fixing the leak finally throttled it. Pouring water through the Cat produced very little flow, although a bit of a soak in detergent solution has considerably improved that so the exhaust will go back on for a hopefully better result.

We checked the fault codes on the car and found the report "Oxygen sensor system control" (52) and "Wrong fuel/air mixture" (32). Interestingly my own BX19TRi returns identical error codes! Can anyone say what "Oxygen sensor system control" indicates?

PS The throttle cable is correctly adjusted and fully opening. The air flow meter seems to be OK too and it has a new air cleaner fitted.
Michael, Sydney, Australia

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Re: Lethargic BX

Post by citronut »

michaelr wrote: Can anyone say what "Oxygen sensor system control" indicates?
i would think its the Lambda sensor not functioning or just fouled up with carbon,
that can also be why the cat was clogged up

regards malcolm
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also own
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JayW
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Re: Lethargic BX

Post by JayW »

The two main reasons for the cat to be blocked are: Excessive oil burning (a compression test will show where this is and whether it's the rings or valves)

and secondly: Excessive mis-firing causing unburnt fuel to enter the CAT. This will collapse it rather than block.

I'd put my money on the former if detergent has cleared it a bit.
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Re: Lethargic BX

Post by MULLEY »

Or is it just the original ancient cat & therefore it was bound to be knackered due to old age?
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michaelr
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Re: Lethargic BX

Post by michaelr »

I must admit my question looks a bit stupid: "Can anyone say what "Oxygen sensor system control" indicates?" :roll:

I should have explained better. There are two oxygen sensor codes possible. One is 52 ("Oxygen sensor system control" ) and the other is 51 ("Oxygen sensor #1") . I really wonder what differentiates these two errors given that I am only getting the former.

Yes, it may well be that the cat has simply reached the end of it's useful life at around 250,000 km. Oil burning does not seem to be a problem and until this sudden loss of power the motor was running sweetly. Indeed, it is still running well and idling smoothly but just lacking in power.
Michael, Sydney, Australia

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Re: Lethargic BX

Post by citronut »

a duff Lambda sensor will cause the ECU to adjust the mixture, in turn make the engine run rich which will foul the cat up

regards malcolm
curent ride
K reg BX 17TD TZD est
also own
K reg D special

no longer have
H reg CX saffari 2.5 TRI (now gone to Malaysia)
R reg xantia 1.9TD est (gone to meet its maker)
loudel
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Re: Lethargic BX

Post by loudel »

Firstly, my appreciation to all who kindly offer their input, and to Michael a huge thankyou for his assistance, without whom I would be just a babe in the woods (so to speak). I have soaked the exhaust in a soluion of detergent for 24hrs, nary an improvement on our initial efforts - a reasonable flow has been established. The exhaust will go back on to the car this sat/sun. I took delivery of the car in Melbourne and drove it quite well up to Sydney that day though towards the end of the drive I noted an exhaust 'fart' from the manifold area. Inspection revealed a loose bolt/spring holding the pipe to the manifold. Michael and I changed the bolts/springs and 'ring'. Since then the car has been gutless on any incline and has mild difficulty in revving to 4k- the exhaust 'escape' having been blocked. I removed the plugs -3 were clean-ish and 1 had some oil (not a lot), could be that it is the culprit. The car is a delight to drive despite its 24 yrs and 250k kms. I am inclined to ram a rod up the cat to clear a channel and suck out any debris.
Your thoughts please. My questions - what is a lamda sensor, where is it, is it replaceable? I'm not often on the website as for my work I have to flit around the ricebowl- currently in Shanghai.
Cheers
Lou
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