Non Start 205 Gti6

[dav1 7]

I have 205 gti 6 on throttle bodies and cams. The car would't start wen i went out to it and i think it has some thing to do with the crank sensor. I say this because i did't have a spark. i could't smell fuel wen i opened the throttle an stuck me nose in. Every time i wiggled the crank sensor plug we got a cough and splutter.I run a omex 500. Some one had put a dodgy connection from the wire to a wire that goes to the plug. In my wisdom i snipped both plug bits off and wired together. Not ideal but just wanted make sure that was definitely the problem. The car fired up i took it for a quick test drive and all was good. Until i got a little way from home then it cut out an wont start. Ive had a few coughs for a second an back fires but it wont start. i had to tow it back. Does the screening round just a bare piece off wire do anything? Any ideas would be great. Hope every one had a good Xmas.

[Anthony 1,000]

The signal from the crank sensor is quite weak, and the shielding is there to help prevent it being affected by electrical noise.

 

It's not immediately clear from your post where the damaged wiring is - if it's the crank sensor side of the connector than just replace the crank sensor with a new one as a matter of course as they're not expensive, whereas if it's the ECU side then it's a little more involved but it needs to be repaired properly given how critical a good, clean signal from the crank sensor is.

 

Depending on the damage and the amount of slack, you might be able to cut off the damaged part and fit a new plug and pins, or you might need to replace the entire cable. While simply joining the wires back together may appear to work initially, it is a receipe for unreliability and running issues in the future IMO

[dav1 7]

Yeah its the ecu wire side not the crank sensor wire.

[dav1 7]

Should there be voltage to one off the wires that goes to the crank sensor? Any other ideas?

[Dizzee stuff 33 1 Cars]

Should there be voltage to one off the wires that goes to the crank sensor? Any other ideas?

 

No, the crank sensor will generate a rising AC voltage when the engine is turned over. If you find the correct two pins at the ECU or at the sensor and connect your multimeter across set on AC, get someone to turn the engine over on the starter, you should see a rising voltage( about 5v )depending on cranking speed.

Edited December 30, 2011 by Dizzee stuff

[welshpug 1,626]

a power probe is ideal for tests like these, the led will flash on cranking if the wires are good

[dav1 7]

Thanks will try this tomorrow.

[dav1 7]

Tried the strobe method no joy. So rang the local tuner and he said the bare wire(i think he said it is earth) in there should not be connected. Disconnecter and it started. God knows how it used to run thow? Just got to sort out me new colin satchell inlet then another map see wat happens. Cheers dave.

[Anthony 1,000]

The crank sensor shield should be earthed at one end for it to work effectively.

 

Possible short between the earth and one of the other two pins, hence it won't start when it's earthed as it should be?

[jimbean 0]

if you have not already..... try changing position of the two wires going to crank sensor ie swap 1.to2 and vice versa..... if the wave is upside down the ecu might not like it

 

jim