another problem just before the MOT Friday

[mac123yre]

The car started to idle high and the idle screw made no difference, the next day when I started the car at first the tick over would be at about 2k then drop down but the car runs ruff misses spits smells rich, no air leaks and the fuel pump runs ok as its new, new leads new cap new rotor, any ideas.

Problem is I had the MOT booked for tomorrow and I was going to take it to the BBWF

[adam quantrill]

With the 350i if it's too high CO I have bypassed the AFM with a small extra pipe (the AFM screw being a bypass pipe anyway).

Do you have a CO meter to set it up with?

Don't forget you are allowed 3.5% so there's a lot of leeway.

Mine was done yesterday and it was actually too lean at 0.5%, I wonder how given the stink the exhaust puts out!

[deeen]

Engine temprature sensor?

[adam quantrill]

Good point - if it is, just short it out with a piece of wire and MOT it.

[mac123yre]

thats strange as it started on a hot day, will try it

[mac123yre]

Replaced the sensor, made know difference but have some one coming over next week to have a look, need another set of eyes.

[combine]

Leak on exhaust system can cause this , near manifold join with silencer ?

[honestjohntoo]

mac123yre said:

The car started to idle high and the idle screw made no difference, the next day when I started the car at first the tick over would be at about 2k then drop down but the car runs ruff misses spits smells rich, no air leaks.

Regarding Temp Sensor

• You replaced the temp sensor and it made no difference?
• Perhaps the sensor was not faulty?
• Did you measure the old one before replacing it?

TEMP.......OHMS........TEMP........OHMS
-10°C....9100-9300....60°C.......500-700
0°C.......5700-5900....80°C.......300-400
20°C.....2400-2600....100°C......150-200
40°C.....1100-1300

• What if the connection from the sensor to the ECU is open circuit?
• What if the earth stud at the rear of the block is corroded?

• The ECU would think the car was cold even after it had warmed up!
• So the hot engine now gets a rich mixture, stumbles, smells rich and eventually (usually) stalls.
• To be sure ALSO measure the sensor from the ECU multiplug!

Regarding Air leaks

• Can you be sure?
• Apart from visual/aural checking for split air rail hoses, intake hose, breather hose, have you checked for:
• Overrun valve (if you have one) jammed open,
• Brake servo system leaking vacuum,
• Blocked crankcase ventilation system,
• Plenum to trumpet-housing seal,
• Breached rocker cover gasket(s).

Look in here for a dynamic air leak detection procedure.

[mac123yre]

Hi Chap, put a 200 resistor in and the tick over dropped so replaced the sensor, think there is a vacuumed leak as can here a hiss near the butterfly, have replaced the seal but still no luck that why I have asked a mechanic to come have a look to give another opinion, with this car I have had lots of luck ALL BAD.

[Transmitter Man]

Alan,

Simple answer.

Do what I've done - keep throwing money at it until it improves

Phil
420 SEAC

[honestjohntoo]

mac123yre said:

no air leaks

mac123yre said:

Replaced the sensor, made no difference

mac123yre said:

put a 200 resistor in and the tick over dropped so replaced the sensor, think there is a vacuum leak as can here a hiss near the butterfly, have replaced the seal

with this car I have had lots of luck ALL BAD.

• No air leaks, then an air leak?
• Replaced sensor made no difference, then it does?
• Confused?

[mac123yre]

Found the main problem, when I removed the water chamber below the plenum forgot to seal the holes (idiot)
however the tick over is still high, have always had tick over problems up and down but seems impossible to get it below 1200, any ideas chaps.