Hi, Ford Puma 1.7 Zetec, year 2000, 50, 000 miles, only recent change is the timing belt- could be significant. Used the car for a bit, then, one day it was idling, I turned on the air- con;, and it stumbled to a stop. Has not gone right or run since. If I start it (OK, and I can hear the fuel pump), it will turn foir a bit, especially if I am quick enough to run it a 2 - 3000 revs, but eventually it starts to die. Checked OBD, had a P0115 (Engine Coolant temperature problem). Changed the sensor, but still there and no improvement. I did tap the MAF once, and it seemed to cure it. Changed that, but the problem is still there. The fuel pump seems to go more often than I remember. So, wiring problem; fuelpump problem, timing or injection?

 

Check the wiring of the Coolant temperature sensor.
Could be a short circuit or a open circuit.

 

Thanks for that. I get 4.4 volts when I measure across the pins of the plug for the ECT sensor, key on, engine off. Do you happen to know an idiots guide to detecting short or open circuits in cars. You dont think it might be the throttle position sensor - there's been a bit of a lag, between accelerator depression and engine speed, for some time?

 

If you clear the codes does the same fault code come back?

Has the camshaft sensor been been fitted correctly since the cambelt been done? It's a bit of a funny setup the way its held in the came cover.

 

4.4V is pretty high for an ECT this time of year. I don't know the exact figures, but that's probably well below the freezing point.
Remove the plug from the ECT and measure in the plug. One wire should be 5.0V (reference supply) and the other 0.0V (ground).
First measure the 5V against a known good ground, then across the pins in the connector.

 

are you saying when u rev and let go the revs hang a little before they drop - do u notice a slight sluggishness when u say rev the engine via engine bay/ throttle by hand - is there a slight misfire //delay when revving up? if so check the coil pack ecu wires ALSO power steering /connector / harness can cause same issue you describe - i left mine unplugged did exactly that - when the cu re-learns idle does cut out too - there are so many scenarios that can cause this - get it all diagnosed - or u can use forscan via laptop/PC pull up fault codes so u aint chasing ur own shadow..