2.9 cutting out
Discussion
Starts, idles, perfectly.
Driving somewhat ok, but every so often it feels like the IGN has been turned off Then immediately comes back after a second.
Doesn't feel like fuel, it's an immediate loss of power with an instant return.
Spark is fine, rigged up strobe to one plug and it's firing within the "shutdown".
Unable to replicate when stationary.
Anybody had similar issue?
Driving somewhat ok, but every so often it feels like the IGN has been turned off Then immediately comes back after a second.
Doesn't feel like fuel, it's an immediate loss of power with an instant return.
Spark is fine, rigged up strobe to one plug and it's firing within the "shutdown".
Unable to replicate when stationary.
Anybody had similar issue?
Sound like a wiring issue. Have you checked the yellow connector under the steering column? It might look OK on the outside but could still be burnt out inside. Like this...[url]
|https://thumbsnap.com/ekO1cnGQ[/url]
If the connector is OK then the next step is to check all the other wires off the back of the ignition switch. A loose wire on the back of the tacho can cause this problem. If still nothing obvious, start the engine and jiggle every wire you can find under the bonnet to see what happens. Start at the coil and work out from there.
|https://thumbsnap.com/ekO1cnGQ[/url]If the connector is OK then the next step is to check all the other wires off the back of the ignition switch. A loose wire on the back of the tacho can cause this problem. If still nothing obvious, start the engine and jiggle every wire you can find under the bonnet to see what happens. Start at the coil and work out from there.
I have indeed replace the connectors under the steering column, as they were as pictured, rather nasty. I also had a couple of poor connections around ECU area and have tidied up the loom in general where many mods have been made. I have tried the old wiggle test with nothing conclusive sadly
Disconnecting the tps completely yields the same result so I'm fairly certain it's not this.
It's seems more prevelant at low rpms, pulling at junctions etc. although it will happen on normal travelling .
I have checked all the usual suspects with nothing conclusive being thrown my way.
Disconnecting the tps completely yields the same result so I'm fairly certain it's not this.
It's seems more prevelant at low rpms, pulling at junctions etc. although it will happen on normal travelling .
I have checked all the usual suspects with nothing conclusive being thrown my way.
On mine similar symptoms were caused by the AFMs .
Cured completely by cleaning the tracks inside and swopping the plugs over from the Top AFM to the bottom and vice versa. I think that poor contacts on the tracks at certain positions were telling the ecu that there was no airflow so it cut the fuel. Then when the car slowed the AFM contact moved to a clean section of track signalling airflow so the ECU switched on the injectors again. Good luck.
Cured completely by cleaning the tracks inside and swopping the plugs over from the Top AFM to the bottom and vice versa. I think that poor contacts on the tracks at certain positions were telling the ecu that there was no airflow so it cut the fuel. Then when the car slowed the AFM contact moved to a clean section of track signalling airflow so the ECU switched on the injectors again. Good luck.
A few years ago, my S2 would intermittently cut out at about 3000 rpm, drop back to about 1500, then pick up again. If that is what yours is doing, the culprit was the throttle potentiometer as someone previously suggested. It is a known problem, mentioned at the end of chapter 3 of Steve Heath's book :
"The symptoms are that the engine would suddenly not rev above 2500 when the throttle was open. The engine then starts to cut out and after 3-5 seconds cuts back in again. The cause is a faulty throttle position sensor. This can also cause the engine to cut out at other rev ranges. The sensor gives a faulty reading and the EMU tries its best to work out what has gone wrong. In a lot of cases it will cut off the fuel, and this causes the gagging. It is like the rev limiter coming in. "
"The symptoms are that the engine would suddenly not rev above 2500 when the throttle was open. The engine then starts to cut out and after 3-5 seconds cuts back in again. The cause is a faulty throttle position sensor. This can also cause the engine to cut out at other rev ranges. The sensor gives a faulty reading and the EMU tries its best to work out what has gone wrong. In a lot of cases it will cut off the fuel, and this causes the gagging. It is like the rev limiter coming in. "
lewdon said:
On mine similar symptoms were caused by the AFMs .
Cured completely by cleaning the tracks inside and swopping the plugs over from the Top AFM to the bottom and vice versa. I think that poor contacts on the tracks at certain positions were telling the ecu that there was no airflow so it cut the fuel. Then when the car slowed the AFM contact moved to a clean section of track signalling airflow so the ECU switched on the injectors again. Good luck.
Hi Iewdon! How do you clean the tracks?Cured completely by cleaning the tracks inside and swopping the plugs over from the Top AFM to the bottom and vice versa. I think that poor contacts on the tracks at certain positions were telling the ecu that there was no airflow so it cut the fuel. Then when the car slowed the AFM contact moved to a clean section of track signalling airflow so the ECU switched on the injectors again. Good luck.
To the best of my recollection,( it was about 6 years ago). The covers of the AFMs are held on by silicon sealant. carefully cut round with a stanley knife. I cleaned the tracks by rubbing them with a soft cloth and methylated spirits.and used a strip of writing paper dipped in meths between the track and the slider to clean the slider
Its also worth swopping the top and bottom AFM over (or the plugs) as one is connected by three wires and the other by 4 so they are giving different signals to the ECU. Reseal after with new silicon - I used the non acetic acid- non corrosive stuff intended for electronics. Good Luck.
Its also worth swopping the top and bottom AFM over (or the plugs) as one is connected by three wires and the other by 4 so they are giving different signals to the ECU. Reseal after with new silicon - I used the non acetic acid- non corrosive stuff intended for electronics. Good Luck.
Edited by lewdon on Tuesday 26th May 18:52
Edited by lewdon on Tuesday 26th May 18:53
Edited by lewdon on Tuesday 26th May 18:56
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