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Intermittant ignition failure
dan8400 - 11/4/11 at 10:44 AM

Morning all,

Recently I've been enjoying the sun in the Tiger. It has developed a problem. Seems to loose ignition. Sometimes under acceleration/overtaking sometimes when just tootling round town.

I can't put my finger on the problem. I loose all power (as if if I've turned the key off or something) If I flick the ignition key off then on the exhaust "pops" and i'm back to full power.

I'm running 1.8 zetec on bike carbs and megajolt.

Don't think it's a dodgy ignition barrel (sierra) but I could be wrong. Key isn't loose or anything. Also, sometimes loose the rev-counter (drops to zero) when driving then it comes back on sometimes it goes then I loose power/ignition


Thanks
Dan

[Edited on 11/4/11 by dan8400]


r1_pete - 11/4/11 at 10:59 AM

Is the rev counter powered from the MJ? if so it sounds as though you have loose connections or dry joints in the MJ or its connections, I would also check the ignition switch connections are clean and tight.

It could be the switching off / on produces a spike which overcomes the poor connection.


RoadkillUK - 11/4/11 at 11:35 AM

This is interesting Dan, I have the same problem, it's not as bad as it used to be, it used to cut out on roundabouts (as well as randomly). We changed the ignition barrel and it's much better, only does it now very infrequently and usually when cold.

I tested my theory by bypassing the ignition barrel by using 2 peices of wire, one for perm ignition and touching (like in the films ) for the starter.

HTH

I'll keep an eye on this thread, see what happens.

Edited to say that we have the same setup, 1.8 Zetec, bike carbs and MJ.

[Edited on 11/4/11 by RoadkillUK]


MkIndy7 - 11/4/11 at 01:09 PM

Is the rev counter powered from the Megajolt? Or completely separate?

Might be worth checking the proximity of the Crank Position sencor and the strength of it's mounting bracket, if it vibrates at certain RPM's or conditions it could be loosing the signal. If it was a fault with the megajolt it would revert to limp home mode if it's still using the EDIS module.


woolly - 11/4/11 at 01:16 PM

had similar twice now with MJ. but on a pinto


1st one was the wire breaking as it goes in to the housing of the crank sensor.
found by gently moving the wire whilst ticking over, then it would stutter or stop.

2nd turned out to be the distance of the sensor to the trigger wheel was to far away.
this was harder as it only happened at 2100 revs either side ok.
both cases just as if you had turned the key off and on. and the rev counter going to zero or fluctuating badly.


dan8400 - 11/4/11 at 03:06 PM

The rev counter is powered from the MJ directly. Haven't sat down and checked anything yet. Thought I would see if anyone has had the same trouble first


Thanks
Dan


dan8400 - 11/4/11 at 03:11 PM

Using EDIS module with Megajolt. Just to clarify

Also the crank sensor mounting is part of the engine block casting so hopefully that hasn't moved lol.

Thanks
Dan

[Edited on 11/4/11 by dan8400]


ditchlewis - 11/4/11 at 07:14 PM

I may be a long way off the track but had a similar problem on friday, it turned out to be the fuel pump.

are you running an mechanical or electrical fuel pump? once home i found the fault to be loose connection on the power supply to the pump, the engine would die and stop. after cranking over a few times it would run again... well untill it stopped altogether on the busy duel carrageway.

it,s just a thought but it might help.

regards

ditch


RoadkillUK - 11/4/11 at 09:31 PM

If Dan's issue is the same as mine, the ignition needs to be switched off and then back on again. It won't start again without.

I've got it down to a fine art, ingition off - on, lift clutch, vroom vroom

Again, same setup as Dan, Edis and original sensor, original hole.


dan8400 - 12/4/11 at 06:19 AM

I have an electric fuel pump. It keeps going all the time when stopped or started (obviously with the key on)

Sounds the same as your problem RoadkillUK



Thanks
Dan


MkIndy7 - 12/4/11 at 09:09 AM

I only ever had something similar happen once with the Megajolt and that was after a long haul up the M6, just coasted over to the Hard shoulder switched it off and back on again for it never to happen again (can't rememeber if it would refuse to restart without switching off and back on presume I'd have tried bumping it off while still coasting).
Never did find anything wrong with it, just presumed maybe a stone had jumped up between the sencor and the trigger wheel or something really freak.

Could underbonnet Temps be playing any part? The EDIS is mounted to a solid metal to displace any heat from what I remember, have you done anything similar? Or is there plenty of airflow over it.


dan8400 - 12/4/11 at 10:25 AM

The EDIS is mounted flat on to aluminuim surface but is under the dash. Would turning it on/off kick it back into life if it's already hot? And does it get hot?

Thanks
Dan


gdp66 - 12/4/11 at 10:32 AM

had a similar issue when first on the road.
I think it was due to earthing, so put an extra earth strap from the gearbox to the chassis.