Mi16, 1.9 Not Firing, M1.3

[ifcho 0]

Hi,

 

We recently planted a mi16 engine inside my brother's car (205GTI but this was all done in a garage 400km away from me. They couldn't fire the car for nearly two months, so I went and towed the car back with my 205 Cabriolet, it was a pretty hard drive, but only took us 5 hours and a half

 

So the next day we tried to fire it up and after two or three hours messing with the wires it fired (only on 2-3 cilynders though, due to crap ignition leads). We replaced the leads and I put the loom in the car as neatly as possible.

Since then I cannot fire it - the fuel pump relay does not click at all and does not activate the fuel pump.

 

The first relay that gives power to the ECU clicks fine after I give (+) to a thick blue wire, which is spliced with three other wires - one for the commutator(i'm not sure how you call this...it's a little black thingy which provides signal to the coil) one for the coil, and apparently one for the ECU.

However, the second one relay does not click. From my understanding, the ECU should give this relay (-) through pin 3.

 

 

I checked the wiring at the ECU multiplug and it gets power and (-) at all the places it should.

 

May I be missing some earth? Does the ECU wait for an earth from some of the sensors? Is it possible that a faulty coil may be stopping it from powering the FP?

[ifcho 0]

any ideas

[ifcho 0]

I checked the signal from the ECU directly on the multiplug and when powered on pin 3 (fuel pump relay control) there is 12V signal.

However, according to autodata, there should be 0-1V for 1 second and then 12V, after that when engine is running again 0-1V

[ifcho 0]

thanks for the numerous replies

 

I finally found the problem. Turns out that the Motronic m1.3 ecu does not prime the fuel system on ignition, it starts the fuel pump only after it gets signal from the CAS sensor...but I had to find this the hard way.

The problem was a dodgy CAS sensor. I replaced it with one I had lying in the garage and it started the first time....

[nick 3]

We all knew you would get there in the end...... so much more satisfying to work it out yourself...

 

Nick

[ifcho 0]

actually the problem wasn't even the CAS sensor...it was the plug for the CAS sensor in the loom...one of the pins had slipped off the plug and was just barely making contact...

[ifcho 0]

well I have a little struggle with the sensor loom.

 

The car does not have two multiplugs, only has one, with 4-5 wires, like this one:

 

However, I don't know which wire is for the RPM, i guess it should be the blue wire that is in some green pipe, along with a black wire, which must be a shield of some sort?

But there is the same wire coming from the accessory harness, on the right side of the car

So which one should it be?

 

Also, wiring the wire I have coming out of the coil (it is with some stupid brown multiplug) to each one of those does nothing actually. Does it also need the shielding black wire to be earthed, cause this may be the cause of my issue?

[luggy 13]

The car does not have two multiplugs, only has one, with 4-5 wires, like this one:

 

However, I don't know which wire is for the RPM, i guess it should be the blue wire that is in some green pipe, along with a black wire, which must be a shield of some sort?

 

 

Mi16 black multiplug, bottom left of the multiplug there are 3 wires, 1 black 2 green.

Notice the left wire is earth and the black wire from the rev counter is connected to earth.

Light green wire (below grey 52a) is the rev counter feed. Pic courtesy of Dee.

 

Hope this sheds some light on your situation.

[ifcho 0]

yes, that's the wire, coming right out of the coil, as on this pic:

http://img48.imageshack.us/my.php?image=2009081527ju2.jpg

 

(i cut off the black mi16 multiplug )