Helping a friend who's saxo won't run.

[leighk18]

Aup guys not been on here in ages just trying help my friend out with his saxo.

It's a mk2 1.4 3 plug ecu.

He says he was going home last night then it cut out on him and he lost all power. He manged to get it going again but it soon died again. He noticed the ring connector to the alternator had broken of so he manged bodge it to get it home. Even tho it kept cutting out. Took the battery off and charged overnight.

Today he put on a new ring connector on and all started fine then it cut out again. So I got my multi meter and checked the battery was good. (New battery) and held 12.5v easy. When running it got to 14.5v perfect. Then it just cut out again. and refused to start. Happily turns over all day but just won't fire up.

I noticed the crank sensor was wet so took it out give it a good clean up. And started straight up but then would rev to 4k. It did this a few times. Then stoped starting again. And since then it's refused to start.

Iv checked and sanded down the earth points. the gear box wire does not look the best with some oxidation so that could do with been stripped and a new connector but car started fine before I noticed that.

Iv noticed there is NO eml on the dash with key in either postion or why cranking.

The pump is not priming. It was when the car started but idled at 4k and since then it does nothing. Checked with the meter and was only 2.5/6v when been cranked Added a 12v live to it and the pump ran straight away. But it still did not wanna fire up.

Checked all sensors etc are plugged in. and have triple checked the fuel cut off switch.

All fuses are fine. also checked the fuel pump relay under the ecu and get 12v on both pins which should have voltage.

A last try was I have a Bluetooth obd reader so I thought id give it a go and it says it can't find the ecu. Which could be just a coincidence as never tryed it in a citroen before or could be a problem.

But seems a bit strange that the ecu would just pack in for no good reason?

So any of you guys got any ideas on what I should try next? I read on one of the threads about the ecu power wire can go bad and this would stop the car seeing the ecu and stop It from running all toghter but have not got the pin outs for where to look for this wire.

Sorry for long post haha

[stevo67]

You try swapping over the fuel pump relay,located under the ecu.

[leighk18]

Not got a spare one to hand.

The fact there is no engine management light is throwing me off.

[Ben_SaxoForte]

Could be a bad fuel pump had a similar issue with mine a while ago, in my experience it's quite rare a saxo will throw a code if something is wrong with it lol

[axsaxoman]

It is possible the sparking or shorting of the altenator wire could send a spike to ecu and fry it.
this is why you should never jump start a car with an ecu +battery should be disconnected when charging --thats why they put that quick fit battery clamp on modern cars--so its easy to isloate when doing things
If you can find a similar car and "HOT swop" the ecus and it runs --then its the ecu -
the fact your code reder cannot find the ecu is not good --maybe worth taking to garage with proper diag tool ?

[leighk18]

So had a play again this morning it's defo a wire issue. Just can't seem to track it down. If I mess around with the coil pack plug the engine light comes back on. My obd can find it and it starts then it goes off again. And engine light goes back out so it's got to be a bad ground or doggy power wire to the ecu.

[leighk18]

Well manged to get another fuel relay and it now starts and can find the ecu.

Only problem now it just wants to rev at 4k no matter what. Did a code scan only fault showing is the 02 sensor. Which comes back after been cleared.

Iv took off and cleaned the icv with carb cleaner but stll the same. If I unplug the map sensor then it won't idle at all but stops it from revving its nut offs.

Any more ideas guys?

[stevo67]

Disconnect the battery for 1/2 an hr,then take for a short drive.

[leighk18]

Cheers mate it kept doing it even with battery off all night. We replaced the icv with a 2nd hand one and was fine. Then after he was out in it for 7 hour it started sticking at 2k. So cleaned up the new one and was back to normal. So if the probelm comes back again think he will have to buy a new icv.