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Discussion Starter · #1 · (Edited)
1993 214 16V MPi Misfiring on Acceleration When Warm and Wet

This has been an ongoing problem for ages, I had assumed it was sorted with replacing the lamda sensor.

30 Mile trip down the motorway yesterday (weather conditions: very wet), get off the slip road and then it starts.

If you go below 4000 revs it starts to misfire, you put your foot on the accelerator and it dies. Stop the car and let it idle, idles perfectly. Put your foot on the accelrator to pull off as normal, it dies and cuts out. Do a juggling trick with clutch and accelrator boyracer stylee (above 4000 revs) and I can manage to pull off and by keeping it in a low gear can actually manage to get somewhere, but the poor engine having its nuts revved off :(

Now if I do ever manage to get to my destination, park it up for a couple of hours it will be fine for the rest of the day.

My best guess is water getting in somewhere, but where and on what?


The car has had new

HT Leads
Distributor Cap
Rotar Arm
Fuel Filter
Lamda Sensor


and the throttle sensor has been checked.
 

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Check that water/condensation or oil is not getting onto the rotor arm.
Maybe another component is on the way out, coil perhaps....

If you have the car sitting in neutral during this problem period, and then just try to rev it a little (as if pulling off), does it struggle to increase revs and try to die or is it free-revving??
 

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I'll add that the coil, fuel filter and ECU coolant temp sensor are all new too. and when the problem occurs it won't rev in or out of gear but plenty of fuel is getting through as witnessed by the flames coming out of the exhaust!
 

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That is next on my list to change. The fault is very intermittant. Is there any way to test the sensor other than replacement with a new one?
 

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Hi, Sound like the TPS (Throttle position sensor) may be short circuit or something causing the ignition to over- advance giving you flames. Theres an idle switch in the TPS which is working okay thats why you get perfect idle. It needs 4000rpm+ cause thats were the ECU thinks the throttle is all the time.
 

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I had a similat idea too so I changed the TPS for a differnt one but still no change. (Sorry I forgot to mention it above as I've changed so much on this car but the infernal problem is still there.

Is there a throittle pedal switch on this car?
 

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No i think the throttle is attached to the throttle body via a cable and the sensor is in there. I would still think it was the crank sensor tho.
 

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Arghhh. I'm getting fed up with this car now.

Still when warm it'll cough and splutter when wet then be fine for the rest of the day.

It has had new:
Crank sensor
Distributer cap
Rotor arm
Coil
(second hand) Throttle position sensor
HT leads
Plugs
ECU temperature sensor

Any other ideas as to what could be causing this before it meets its maker?
My only guess is an ECU.. Anyone got a spare one?
 

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Discussion Starter · #10 ·
:***::***::***::***::***::devil2::devil2::mad: :mad:

Weather Condition: Chucking it down!

The ******* car has done it again this morning, this time on a busy motorway. Managed to get it off the hard shoulder and keep it above 4000 revs once the traffic had dies down. 20 miles down the motorway doing this (poor engine :()

5 miles through residential area revving the nuts of it, sodding thing dies on a roundabout and won't start :mad: Eventually managed to get it going, hitting the rev limiter going round the roundabout :( and made it to my destination


It is not the crank sensor this was replaced at the weekend. Its not the distributor or rotar arm, this were replaced for new items the second time this weekend.

Its also had new HT leads (twice), fuel filter lamda sensor, igntion coil and ecu coolant temp sensor. It has also had the throttle position sensor tested with another one too.


I am at a loss, if its not sorted the thing will be off to the scrapyard had enough. It must have had every new thing going in the past 6mnths and still the problem is here. Its a shame as its a really nice car, and has been well looked after.

Does anyone have anymore ideas on what the problem could be please?


The only thing that hasn't been replaced is the ECU (MKC 101610 from memory) so if anyone has one cheap I will be interested.
 

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Hi ETV & skatichick, you must be well fed up with this motor. It is obviously a difficult one to track down, and like you Im running a bit thin on ideas. If it only does it when wet it kind of makes things harder to diagnose seeing as it is not HT related.

I wonder if there is a problem with the under bonnet fuse box as it has a printed circiut sandwiched between two layers if there is moisture or corrosion in there this could affect the ECU and coil supplies from main relay and MFU, I suppose its worth a try, along with your ECU theory.

Regards Gary :)
 

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Get it to a garage that can do a diagnostic. I had the ECU of my 420 checked yesterday, it was full of codes. The guy reset the codes and no new ones appeared, but the car is now running much better, which is odd, but a fact nonetheless.
If nothing else it may tell you what the problem is. I got charged nothing ,but even if i had to pay for a full hours labour it would have been worth it.
 

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Discussion Starter · #15 ·
*screams loudly***** What did we have today, RAIN and what did the car do play up again with a brand new cat on (I do hope it hasn't wrecked it).

Fast losing patience with the sodding thing, it has been for diagnostics and they said everything was fine with it.
 

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This may sound daft, but are all your engine bay earth points in good order?? Could well be a problem with those.

Its piddling down in Aylesbury :(
 

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Discussion Starter · #17 ·
conkerman said:
This may sound daft, but are all your engine bay earth points in good order?? Could well be a problem with those.

Its piddling down in Aylesbury :(
Yup, the other half cleaned them all up as he thought it could be that too.
 

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Hi, when the weather dries up, why not try wetting one by one the usual suspects under the bonnet to try reproduce the fault. You could use something like one of those sprays for spraying indoor plants. :idea:

Cheers Gary :)
 

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Try this.....
Rev the engine using your hand on the throttle linkage at the throttle body, see if it revs freely or hesitates....if it hesitates you have a switch on the pedal.

Also carefully check the wiring loom at the coil, I think (hope) you will find the negative terminal in very poor condition, when it rains this area gets very wet.

Regards
DaveH
 

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Discussion Starter · #20 ·
Respot said:
Try this.....
Rev the engine using your hand on the throttle linkage at the throttle body, see if it revs freely or hesitates....if it hesitates you have a switch on the pedal.

Also carefully check the wiring loom at the coil, I think (hope) you will find the negative terminal in very poor condition, when it rains this area gets very wet.

Regards
DaveH
It hesitates/misses when rev'ing from the throttle body as well and not just from the pedal. Not sure on the coil, I might pop out and look if it gets a bit drier outside.
 
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