BX Misfiring

Ian Fearn · Post by **Ian Fearn** » 05 Aug 2005, 01:33

Hi there,
My 1992 BX Gti has got a real problem. It would appear to be misfiring constantly. Power is non-existant.
Tonight i've changed the plugs, leads and coil pack and its made not one bit of difference.
Any ideas?

citronut · Post by **citronut** » 05 Aug 2005, 01:43

head gasket?
regards malcolm

Stinkwheel · Post by **Stinkwheel** » 05 Aug 2005, 01:51

Its usually coil pack on these engines so yes, could possibly be headgasket (water in the combustion chamber - I had this on a Xantia)

Ian Fearn · Post by **Ian Fearn** » 05 Aug 2005, 02:01

No coolant issues apparent, runs at normal temp and not lost any water

citronut · Post by **citronut** » 05 Aug 2005, 02:03

i had a customers BX GTI with distributor less ignition,had on going prob with intermitant missfire,never did find out what it was,belive it was bad conection in engine management loom which runs across engine into large round plug,because we could make it missfire some times by moving the loom around but not every time
regards malcolm

Ian Fearn · Post by **Ian Fearn** » 05 Aug 2005, 02:10

This is constant. It genuinly feels like one piston is out and it stinks of fuel from the exhaust

Stinkwheel · Post by **Stinkwheel** » 05 Aug 2005, 02:12

not something daft like a burnt valve is it??

Ian Fearn · Post by **Ian Fearn** » 05 Aug 2005, 02:16

After this lot thats been my train of thought.
What would be the exact symptoms and how can i tell?

Stinkwheel · Post by **Stinkwheel** » 05 Aug 2005, 02:23

As i understand it a burnt valve will cause uneven running, missfiring etc. Have you pulled the plugs? Any of them look odd? Either too clean or too black? This might give you some idea what cylinder the fault is occuring with (assuming its only one)
As another question, how/when did it all start? Re-reading your initial post it sounds like it might be something daft like water in the fuel or something.

Ian Fearn · Post by **Ian Fearn** » 05 Aug 2005, 02:30

I'd been away for a week and the car had sat untouched. I drove approx 6 miles and then all off a sudden came to a stop at traffic lights and the problem reared its head. I'd not been thrashing it at all.
The car HAD a full tank of juice and has done around 150miles on it with no problems until this.
ONE plug is slightly darker (noticeably) than the rest. Like an idiot i cant remember which cylinder it came out of. But i've got a sucpicion.

Stinkwheel · Post by **Stinkwheel** » 05 Aug 2005, 03:16

Hmmmm odd,
without seeing the car i think i (we) could clutch at straws all day.
If as you say you have changed the coil pack (was it new) i would possibly get new plugs, leads, dizzy cap and arm (they do have them on the 8v GTI dont they?) i would also possibly try to drain the fuel system and re-fill, also change the fuel filter.
If after all this it still persists its time to seek proffesional advice.

czenda · Post by **czenda** » 05 Aug 2005, 13:26

I am not sure about relevancy of the following info for GTI, but anyway:
I had similar troubles (erratic starting etc.), in the end it was a faulty ignition module. It is a black/blue (or grey) plastic box about 5 cm x 10 cm, located under ignition coil, if I remember right, it is marked BOSCH MTR 01 or similar. It is screwed on Al plate with two bolts. The Al plate works as a passive cooler.
The backside of the module must be greased to provide sufficient heat transfer to the plate - if it is not, the module overheats and burns in the end.
After getting the "new" module, I used the paste used for CPU on its backside, however, copper grease should work just fine.

ItDontGo · Post by **ItDontGo** » 05 Aug 2005, 13:48

If it stinks of fuel them its almost definately an ignition fault or engine fault that is as opposed to fuel. You could pull the LT wires of the coil and crank it and if it sounds even with a constant crank speed then its likely that the cylinder compressions are the same. Obviously if it suddenly goes faster on one cylinder then there is a problem with one of them.
You can find out which cylinder it is by pulling the HT leads off one by one as the engine is running. Make sure you do this with a plastic tool or something with a rubber handle though. Actually for you neighbours' amusement just use your hands

You could then swap a few HT leads about when you have found which one it is to check its not then HT leads. Then I suppose you need to worry about the coil, but if the coil does them all then that should be OK. After that I suppose you're ****ed. Second hand cars are very cheap these days.
Oh look you cant say ****ed. Well in that case **** the ****ing ****ers who ****ing made it so that you cant ****ign say ****. I never saw the problem with saying ****. Its only a ****ing word for ****'s sake. People shouldn't be so ****ign sensitive.

born2die · Post by **born2die** » 05 Aug 2005, 18:28

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by ItDontGo</i>

.
Oh look you cant say ****ed. Well in that case **** the ****ing ****ers who ****ing made it so that you cant ****ign say ****. I never saw the problem with saying ****. Its only a ****ing word for ****'s sake. People shouldn't be so ****ign sensitive.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Ok who put the uppers in his tea[:D]

cornishbx16v · Post by **cornishbx16v** » 05 Aug 2005, 20:03

have you checked the injectors?????
had a similar problem with miune a while back and it seemd only to run on 3 cylinders!
checked everything, and changed plugs leads, cap and arm, no difference, even had the head swappe dover with one of my old engine, swapped the injectors over and solved the problem! turned out one was semi blocked! (one nearest the gearbox end of the engine!)
does sound like it could be them!! if you have a spare one put it in place of the one where you think it is and see??