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rover_200_coupe
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Discussion Starter #1
Well my '92 Rover 214Si has been for its MOT, and has failed on the emissions test, something isn't right. I've noticed that when idling that it is a little lumpy and that's constantly, have searched most of the forums and looked at and changed the obvious, plugs, leads etc, but still can't identify the fault. Any ideas? I'm guessing the idle problem is ECU related, either itself or via the sensors. The performance is fine above idle, though consumption might be a tad excessive but I've only my old 414 to compare to and it seems about the same. I noticed something a little while back when I changed the alternator though, after having the battery disconnected for the better part of a week that when taking it for a test drive that there didn't appear to be an idle problem, but it came back after a few miles. Sorry for the essay, just trying to explain my situation, any help would be gratefully received. Cheers
 

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rover_200_coupe
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Discussion Starter #3
Thanks for your advice fevsisere, I have gone and replaced the green air temperature control valve, and I think its running better, but another emissions test is the only way to be sure. I have also changed the coolant sensor. Quick question what is the light blue connector down below the green air temperature control valve? It appears to run off the ECU too but was unable to ID it. Cheers
 

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rover_200_coupe
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Discussion Starter #5
Well the plastic coating on the wiring to the crank sensor connector was split so I used some insulation tape to seal the wires. I sent it off for a retest today, not the results I was hoping for, it failed again!

These are the results from the 1st test (before I changed anything)
Fast Idle Test
CO % Vol: 1.170 (0.300 MAX) FAIL
Second Fast Idle Test
CO % Vol: 1.029 (0.300 MAX) FAIL
Natural Idle Test
CO % Vol: 0.510 (0.500 MAX) FAIL

2nd Test (Today)
Fast Idle Test
CO % Vol: 5.370 (0.300 MAX) FAIL
HC ppm Vol: 325 (200 MAX) FAIL
Lambda: 0.856 (0.950 MIN - 1.090 MAX) FAIL
Second Fast Idle Test
CO % Vol: 1.588 (0.300 MAX) FAIL
HC ppm Vol: 210 (200 MAX) FAIL
Lambda: 0.977 (0.950 MIN - 1.090 MAX) PASS
Natural Idle Test
CO % Vol: 0.457 (0.500 MAX) PASS

So whatever I did to my car, cleaning sensor connections, fixing broken wire casing, and changing 2 sensors -admittedly from a scrappy but what chance to find 2 that would make the car worse! Unless I'm missing something like a dodgy wiring harness/ecu? Any ideas or help would be appreciated!
 

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rover_200_coupe
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Personally I'd try a new coolant temperature sensor. I had no end of idling issues with my car, replaced that for £7 and fine ever since.

Most sensors are fairly cheap, so probs worth renewing them.

Make sure you replace the sensor for the ECU and not the one for the temperature dial on the dash.

You could also check that the hose from the inlet manifold/filter housing to the ecu is clean and that air can pass down it. It's the manifold absolute pressure sensor, and controls the fueling depending on engine load. Sometimes the hose gets full of muck.

Hope this helps.
 

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Discussion Starter #7
I ordered a new coolant sensor, but later found out that the wrong 1 was sent - grr! So I'm waiting on that, in the meantime a good friend has a scantool which we used to read the fault codes. 2 faults presented themselves, a potentionometer fault, and an absolute pressure sensor fault - could this be because I disconnected them to check the connections? We then cleared the faults, and they don't seem to have come back (yet...) We also noted on the scantool using the live data that the oxy sensor (lambda?) was running in open loop and it didn't go to closed loop at all (car was warm). Also indicated was a stepper motor failure, wouldn't this show as a fault? It makes all the usual noises, how can I tell if it has had it? Many thanks for any advice. Mitch
 

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mY 214 has struggled for the past 2 mot's on emissions but it failed yesterday the garage have told me I need a new cat, so shall see what happens next week


Sandie

apparently its the original one on there still
 
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