Hi everyone I can't get my head around this problem I have changed fuel pump ,fuel filter, plugs, ht leads, coil pack ,O2 sensor, coolant sensor, maf sensor idle control valve , cleaned egr valve ,cleaned k&n airfilter , and still having the same problem it passed mot on emissions I tried pulling codes off ecu but item doesn't work it is 3 pin connector I've also tried to do a blink test that doesn't work either

The car starts up from cold no probs it's a bit hesitating and juddering on pulling away I have replaced rear gearbox mount but when slowing down to park up of drive in first before stopping tends to high rev to about 1500 then after about 5 secs eventually goes down to normal but if I'm driving for about 10 mins the engine light comes on water temp is normal fan kicks in quite frequent no smoke coming out of exhaust but I also notice when I'm driving and take foot off throttle car tends to hold back and not stay at a smooth drive I have spent a lot of money on it and time even had head gasket replaced and all sensors replaced apart from the sensor that goes into air filter long round plastic thing with 2 pins has a little resistor in the end of it I think its a air temp sensor ? If I get pic will post it

Any ideas guys really want to get it sorted and I have also got a power drain on car I think it is diode in alternator as I replaced battery and still same problem goes flat after a couple of days of not using it

This is the air intake sensor

Would the water thermostat throw a engine light if not working properly

no thermostat won't throw an eml. You can test thermostat but just holding the pipe from it to the rad as the car warms up - it should stay cold and then suddenly jump up in temp when the thermostat opens (around 60 degree's-ish).

You really need to get to the bottom of why you can't read codes, from reading all your posts i suspect there must be a wiring issue with the diagnostics port or something.

Elxpunto90 said:

Hi everyone I can't get my head around this problem I have changed fuel pump ,fuel filter, plugs, ht leads, coil pack ,O2 sensor, coolant sensor, maf sensor idle control valve , cleaned egr valve ,cleaned k&n airfilter , and still having the same problem it passed mot on emissions I tried pulling codes off ecu but item doesn't work it is 3 pin connector I've also tried to do a blink test that doesn't work either

The car starts up from cold no probs it's a bit hesitating and juddering on pulling away I have replaced rear gearbox mount but when slowing down to park up of drive in first before stopping tends to high rev to about 1500 then after about 5 secs eventually goes down to normal but if I'm driving for about 10 mins the engine light comes on water temp is normal fan kicks in quite frequent no smoke coming out of exhaust but I also notice when I'm driving and take foot off throttle car tends to hold back and not stay at a smooth drive I have spent a lot of money on it and time even had head gasket replaced and all sensors replaced apart from the sensor that goes into air filter long round plastic thing with 2 pins has a little resistor in the end of it I think its a air temp sensor ? If I get pic will post it

Any ideas guys really want to get it sorted and I have also got a power drain on car I think it is diode in alternator as I replaced battery and still same problem goes flat after a couple of days of not using it

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i think thats a water temp sensor that sends data to ecu

Hi guys I'm back again I've changed inlet outlet gasket on exhaust replaced co2 sensor egr checked timing it's inline just ordered another set of plugs and another fuel filter to see if this would help the problem also I've noticed that when car is upto temp fan kicks in or idling it splutters ever so slight but doesn't have any effect on performance pulls off quick and when you take foot off gas it starts to splutter like little popping noises and still running rich also I've changed all vacuum pipes still running out of ideas

my suspicion is crank sensor

Oh and by the way the power drain was the head unit when I leave fascia of car is fine as soon as it is put in and left the voltage drops dramatic on the Multi meter glad that's one thing out of the way lol

I've only just put a new crankshaft sensor in will look into it again

i still think managing to get some software to read the codes is the ultimate answer here... There must be a way!!!

If only it was that simple I would be happy with the codes I was reading another post on the forum about head skimming when I replaced head gasket The head was skimmed at 0.8 fal would that make a difference to the timing at all to cause the problem just a suggestion

Elxpunto90 said:

If only it was that simple I would be happy with the codes I was reading another post on the forum about head skimming when I replaced head gasket The head was skimmed at 0.8 fal would that make a difference to the timing at all to cause the problem just a suggestion

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I have the same problem when I drive over 15 miles in my 2001 Punto - EMS comes on. I have stopped to let engine cool down but doesn't help. Yet when left overnight goes off again. Can I safely drive this any distance? Have no knowledge of mechanics but know that had 2 new sensors fitted recently.

Have you any misfiring at all or hesitation on driven or bad idling

You should
Be able to plug into ecu and diagnose codes whilst eml is on as it's obd2 compliant

have we come to the final conclusion about the solution for Engine light comes on after 10 mins of driving or acceleration?

Elxpunto90 said:

tried pulling codes off ecu but item doesn't work it is 3 pin connector I've also tried to do a blink test that doesn't work either

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What's the Weber Marelli reference on the ECU?

Time to get to the bottom of this!

doowllats said:

I have the same problem when I drive over 15 miles in my 2001 Punto - EMS comes on. I have stopped to let engine cool down but doesn't help. Yet when left overnight goes off again. Can I safely drive this any distance? Have no knowledge of mechanics but know that had 2 new sensors fitted recently.

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As said, your car is OBD2 compliant -- it's a Mk2 Punto. Any old cheapo code reader (less than £20 on eBay) will be able to read the codes.

Right changed fuel line and fuel filter still no joy with it just waiting for spark plugs now had Bosch in car now bought ngk to serif that helps

fingers99 said:

What's the Weber Marelli reference on the ECU?

Time to get to the bottom of this!

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Bump!

Bosch plugs are crap, but I doubt that's the issue.

Agreed, bosch plugs are awful (i swear by NGK's), but also agreed, if it was plugs it would likely be there from cold and unlikely to just throw up a light when warm etc, it's a sensor issue in my opinion.