Mi16 Cutting Out When Warm

[welshpug 1,626]

afm, broken wiring, dying fuel pump, fuel pressure regulator.

[DGTi 0]

Lol not much then!

 

Assuming that the wiring is ok... which it should be given what I paid, why would a dying fuel pump cause overfuelling?

 

Is there anyway of testing the above?

 

I'd assume that the AFM is the issue given that unplugging it makes a difference, but could it just be that's masking another issue whilst its unplugged?

 

I guess if I went wasted spark, as described I'd still have this issue if it isn't down to the AFM!

 

Should the ECU be controlling the fuel pump in anyway other than on and off? I only ask because as mentioned this is hardwired to the ignition barrel rather than being through the ECU as I believe it should be on the standard Mi set up?

[welshpug 1,626]

never assume!....

 

fuel pump is either on or off, fuelling is regulated by the ecu altering injector pulse width by measuring load with the AFM and throttle switch, fine tuned according to CTS and IAT resistances.

 

fuel pump should indeed be ecu controlled not on an ignition live.

[DGTi 0]

Haha yeah true... if it comes down to the wiring then I'm snookered to be honest... I couldn't find anyone local that was willing to work on it last time and I spent a lot getting it to and from Constella in Loughborough to complete the wiring, and now its so non-standard I wouldn't even know where to start with it!

 

So will having the fuel pump hard wired cause any issues, other than not being the right way?

[S@m 156]

It won't shut off if you crash, thats the main issue.

Edited July 15, 2013 by Sam306

[DGTi 0]

Ah right fair enough.

 

No worries there I guess, you have to be moving to crash!!

 

Starting to get the feeling that even if I do convert it to wasted spark with Megasquirt I'm still going to be faced with the issues I'm having...

[yeti-dj 7]

i had fueling issues with my mi16 and it was the temp sender as well, checked its readings wram and cold and seemed to be fine. Still had problems so just replaced it anyway, problem solved. Car ran like a dream.

 

For all the cost of the sensor i would replace, its worth a try. Or maybe borrow one known to be good, its a 2 minute job to change it.

 

Also have had a plug lead break and cause misfiring randomly, only spotted when the car was running at night and u could see the spark jumping from the lead.

 

good luck.

[katmav 0]

Had the same symptoms on mine due to a broken down coil.

It would misfire when cold, then cut out and not start when warm.

[jackherer 543]

If you're sure you've exhausted everything else try a different starter motor - http://forum.205gtidrivers.com/index.php?showtopic=123111

[DGTi 0]

Hello everyone sorry for the delay between posts its been a bit of a busy time!

 

I managed to get the Mi16 issue diagnosed thanks to Rob and the team at Constella in Loughborough! He very generously agreed to have a look over the conversion and wiring if I got the car to him, and when it got there he went above and beyond sorting out loads of little niggles with the conversion as well as some huge ones, like the cutting out when warm!!

 

Following a lot of trial and error it was decided that the issue was a reduced spark when warm, not a complete loss but a reduction in the strength which is why previous mechanics had seen a spark and ruled that out as the problem!

 

Having replicated the issue we tested all of the individual components which seemed to be functioning correctly, which was a bit confusing. But Rob was determined not to give up and wanted to see the car running properly before it left rather than leaving me with a hunch and more work to do at home, but unfortunately we couldn’t find any replacement ignition parts at such short notice! Luckily after a lot of ringing round Rob managed to get another Mi16 to borrow a dizzy cap and rotor arm from and that solved the problems!! It would appear that the rotor arm was at fault, but it made sense to replace the cap at the same time just to be sure!

 

For anyone in the NW reading this thread and struggling with their 205 I’d highly recommend a trip to Constella!! I’m sure I’ll be back again in the future even though its miles away its worth the journey to know the job is being done right!!

 

Thanks to everyone for there help and suggestions,

 

Cheers

Andy

[Jon_Bmw 13]

Andy

 

I was reading the thread from page one and was saying `rotor arm` in my head because we had the same symptoms about 5 years ago.

 

It was a small burn mark on the cam side of the arm so looked good on initial inspection when removing the cap. Sorry I didn't see the thread 3 months ago!