Bx Wired Mi16 Firing But Not Starting

[chris 417 mi 35 2 Cars]

Ok, my mi engine is all wired up, has oil in, water in and fuel. When the starter is operated turns over but does not want to fire, we have a spark across all plugs and fuel coming into each pot (as plugs were sooty after first few attempts). Any ideas ? could i have the idle control valve and coolant temp sensor plugs mixed up and would this make a difference ?? does the ecu need to be sat on its mounting plate as at the moment its sat in the drivers footwell (didnt want to put all the dash back in untill everything was running smoothly)

[chris 417 mi 35 2 Cars]

also the smaller of the two relays (is it fuel pump & injector?? ) didnt seem tot be energising while attempting to start, the larger one energised as soon as key was turned to click before starter

[jonand 0]

also the smaller of the two relays (is it fuel pump & injector?? ) didnt seem tot be energising while attempting to start, the larger one energised as soon as key was turned to click before starter

 

Had this problem with my Mi recently. The smaller relay I assume is the fuel pump which only energises on cranking and running - bypass to ensure pump is running initially. The sensors shouldn't prevent it from firing. Do you have the correct firing order ? (cylinder 1 is at the flywheel end). If all this checks out look at the ECU earths, the crank sensor, then the ECU itself (my ecu was faulted during my diagnosis).

Good luck

[Dream Weaver 2]

A mis wired coolant temp *can* stop the ECU from firing the engine up - it needs to read the coolant temp to know the engine is cold, and add in more fuel for cranking enrichment.

 

Not sure what ECU setup you're using, bt on my Emerald it wouldn't fire due to a faulty crank sensor.

 

The fuel pump relay should energise when the key is turned to the second position - this send fuel to the fuel rail, the injector relay will be energising when the thing is running.

[pugrallye 0]

coolant temp and idle control miswired would cause an issue, it would be better just to unplug them to intially get it running, if you dont know which way round they go, although obviously your car will run super rich as it will will be thinking is stupidly cold outside, lol and it wont idle correctly,

Since your plugs are black but not wet, obviously your getting fuel and spark, either at wrong time or too much

Edited July 3, 2006 by pugrallye

[chris 417 mi 35 2 Cars]

another question is ...well ive been told the injedtors are batch fired and i assumed that meant it didnt matter which way around they went ...which pizzled me as my other mi16 on bodies has the injectors numbered and in order... but these have no markings on or wiring colour discrepancies ....

[jonand 0]

another question is ...well ive been told the injedtors are batch fired and i assumed that meant it didnt matter which way around they went ...which pizzled me as my other mi16 on bodies has the injectors numbered and in order... but these have no markings on or wiring colour discrepancies ....

 

It would be helpful if you told us what management system you are using. My Mi 1.9 runs Motronic 4.1 which batch fires the injectors, my S16 runs Motronic 3.2 which fires the injectors sequentially. The fuel pump relay on the Motronic 4.1 DEFINATELY only energises on cranking / running as it is earthed via an ecu pin i.e. it does NOT energise at key position 2.

 

Cheers

Jon

[Dream Weaver 2]

Hence why we need to know the management type - my Emerald energises at ign point 2 - passengers always ask what the hell it is

[chris 417 mi 35 2 Cars]

Ok the ecu only has motronic etched on the top

 

Bosch serial number : 0 261 200 119

 

it is the two pin row ecu

[Pug_101 0]

Ok the ecu only has motronic etched on the top

 

Bosch serial number : 0 261 200 119

 

it is the two pin row ecu

 

Got the same module and info I got from Pugtorque was this:

Citroen BX GTi 1.9 litre 16 Valve 87-89 Bosch Motronic ML4.1 0261200119

[chris 417 mi 35 2 Cars]

cheers pug 101 ! right ..so that means the injectors may be in the wrong places, which pins on the ecu correspond to which injector ?? and whats the order ?

 

Might be getting somewhere now

[jackherer 543]

motronic 4.1 batch fires all the injectors simultaneously.

[jonand 0]

cheers pug 101 ! right ..so that means the injectors may be in the wrong places, which pins on the ecu correspond to which injector ?? and whats the order ?

 

Might be getting somewhere now

 

If you read my earlier reply you would see that the motronic 4.1 fires injectors simultaneously.

[chris 417 mi 35 2 Cars]

oh right sorry

 

Hmmm ...back to square 1 then any more ideas ?

[jackherer 543]

is your airflow meter the right way round?

[chris 417 mi 35 2 Cars]

is your airflow meter the right way round?

 

yep ! so are the leads and from the info above too it should have good fuel feed !

 

what next ??

[midnight motorsport 0]

yep ! so are the leads and from the info above too it should have good fuel feed !

 

what next ??

 

 

hello if you are getting a spark, then the crank trigger is working if you are getting fuel the pump and relay are working, are the plugs wet? if not check you have a switched live going to the injectors, with the ign on, put a volt meter accross the injectors and earth, one of the terminals should be live, the ecu fires them by a negative pulse, which should be working as the plugs are firing, if this all checks out, have you checked the cam timing? as this can stop it starting,

[Super Josh 4]

Do you have the fuel supply and return pumbed in correctly i.e Is the fuel pressure regulator doing its job?

 

 

 

Josh

[chris 417 mi 35 2 Cars]

Do you have the fuel supply and return pumbed in correctly i.e Is the fuel pressure regulator doing its job?

 

Filter to left side of rail, then from back to tank? thats how it is on my blue mi

 

undefinedhello if you are getting a spark, then the crank trigger is working if you are getting fuel the pump and relay are working, are the plugs wet? if not check you have a switched live going to the injectors, with the ign on, put a volt meter accross the injectors and earth, one of the terminals should be live, the ecu fires them by a negative pulse, which should be working as the plugs are firing, if this all checks out, have you checked the cam timing? as this can stop it starting,

 

yes from what i rememebr last time i had a go two of the plugs were wet, thnk it was 1 & 3 cylinder, the cam timing should be ok as i bought it off someone off this forum who had just taken it out of his 205

[Phil H 16]

Have any wires popped out of the connector and dangling in the rubber boot on the airflow meter plug?

[16v205 9]

Unplug the AFM and try again. The ecu has a 'limp home' mode where it will use a pre-programmed value if it cant find the piece of hardware installed.

 

I had a similar problem when the coolant sensor wire had broken. The sensor resistance was fine, but the ecu wasnt getting a signal. The only way the car would start was to unplug the afm and crank it.

 

Rich

[chris 417 mi 35 2 Cars]

just checked voltages across certain items :

 

injector on pot 4 : o volts

 

Crank sensor : 3 volts on 1 pin

 

Idle control valve: 12volts

 

Air flow meter : Ifyou turn plug so the connectors resemble 't's .... 5 volts on pins 1 and 3 0 on the rest

 

 

 

 

this is with ignition on the click before the starter motor

[midnight motorsport 0]

just checked voltages across certain items :

 

injector on pot 4 : o volts

 

Crank sensor : 3 volts on 1 pin

 

Idle control valve: 12volts

 

Air flow meter : Ifyou turn plug so the connectors resemble 't's .... 5 volts on pins 1 and 3 0 on the rest

this is with ignition on the click before the starter motor

 

have you got voltage to any of the injectors? if not you you have a battery feed problem to the injectors, get a volt meter, put the earth on the batt - terminal, switch the ign on, and put the positive side of the volt meter accross all of the injector wires, both pins on each injector, one side should show 12v, if none of the injectors have a positive feed, then you def have a wiring prob, if you have 12v to the airflow and the crank that should be ok, as the ecu sends the 12v source to these, but the injectors and the idle control valve have a separate 12+, which is switched by the ign key, pretty sure thios is the red wire, on the two plug connectors inside the car, how have you wired this mi16?

[chris 417 mi 35 2 Cars]

The wiring and engine had previousley been in a 205 so all i had to do was feed the ecu plug and two brown plugs into the cabin, plug the brown connectors into where the old 8v ones went and connect the wires to their respective places in the engine.

 

If i have a battery feed problem the only wire i could see needing connecting up was a thick blue wire with a spade on the end near the passenger side headlight, this went into the distribution block that fixes to the slam pannel, are there any other ones ive missed ?

[jackherer 543]

the loom needs an ignition switched +12v too

 

there is a two pin multiplug coming off the section of loom that connects to the coil and ignition amp etc, the thick yellow wire is the switched 12v and the thinner green one is the tacho drive.