poor starting

[s2driveruk]

Anyone point me in the right direction, seems my car sort of stumbles into life rather than a crisp couple of cranks then fires.

Changed the plugs recently and still seems to be the case on a cold start? Plugs were dry and so were lead ends and tubes when I swapped them out

Presuming a sensor or something else which identifies rotation and firing position could be amiss.

Thanks,
David

[max_s2]

coolant temp sensor?

[Nace20]

coolant temp sensor?

which one ? on the head or on water rail ?

[max_s2]

Could be the one on the head, or maybe MFTS. I dont know exactly witch one on a 3B is used for fuel calculations when cold/hot etc.

[s2driveruk]

actually the one on the back is the one i havent replaced so could be a suspect. Also fan failed to run the other night, cant remember if that is linked to the mtfs?

[max_s2]

I think thats a yes. MFTS ir also for fan.
You can mesure resistance of coolat sensor. When engine cold (ambient aprox 20C), resistance must be between 1.5-3Kohm. If totaly out of this range - must be replaced.

[max_s2]

Opz.. MFTS is not for fan. For fan is the one that is screwed in to the radiator. One of MFTS function is to reduce boost (turn off N75 basicly) if engine is too hot.

[Knight Rider S4]

I'd give the dizzy cap a good clean(remove carbon deposits on contact points ) and make sure the rotor arm end is nice and clean , see if that helps

[popdemonic]

IIRC if the coolant temp sensor failed.You may hook up on the CC to see what does the ECU read the on the coolant temp.

[Error404]

PM me your address David, i've got a known good rad switch you can have to see if that helps with your rad fan problem

[s2driveruk]

Alex, you're a gent and you have mail

[4WheelDrifter]

Checking the resistance of the G62 would be a good start.
s2central.net for more info.

[s2driveruk]

good call, cleaned up the contacts on G62 and she now starts crisply again, thanks guys

next step....bloody fan again. cleaned the contacts on the thermo plug at the base of main rad but still nothing so i'll have to drain down and pull it out and see from there. gives me the chance to put on new longer wires and the correct multiplug connector block i have too.

[UrS4boy]

G62 Coolant Temperature Sensor Info for future ref

Checking the resistance of the G62 would be a good start.
s2central.net for more info.

If the G62 coolant temperature sender is broken, the ECU may "think" its cold out all the time, leading to higher duty cycles on the injectors and, therefore, rich runnng conditions (which, by the way, can burn out the catalytic convertors) and poor fuel economy. Part No. is 035 919 369 M (KATE calls it a thermal switch - No. 9 Illustration 919-65 (A10Q, 1993))

The G62 is a temperature-influenced variable resistance. The AAN ECU drives out a voltage (5? 12?) to the G62 via ECU pin T45/55 via a Grey with Brown stripe (GY/BR) wire. The return current is returned to ECU ground pin 30 (presumably via a brown wire).

From Bentley, the G62 (Engine Coolant Temperature (ECT)) sensor test procedure is as follows:

Allow the engine to cool to room temp (68F/20C)
Disconnect ECT sensor from harness connector
Switch multimeter to resistance range
Connect multimeter to terminals 1 and 2 of the ECT
Resistance must be 1500 to 3000 ohms

IF NO = replace ECT
IF YES = check wiring between sensor and ECM (ECU)

Reference: Bentley pg. J28-22

[s2driveruk]

anyone have a known good G62 I could check with, beginning to suspect this little chappy as part of the problem with saturday's performance issues

cheers
David