Erratic idiling when umder electrical load

[Neilc]

Hi I have a problem with my 1999 (T) 1.6cc Focus which is really puzzling me and my mechanic.

The car starts and drives lovely and during the day ticks over normally at lights and junctions etc, maybe taking a bit longer than usual to come down to idle but not excessive.

The problem is as soon as I turn on an electrical item (Fan blower, Heated screen, Head lights etc)the idle speed dips dramatically if I turn on all at once it has even been known to stall, but most times it just about saves itself and then returns to just below normal idle speed.

Obviously during the recent cold spell I am using all the electrical items mentioned above.

The local auto ecectrician has checked the alternator output and it is fine.

This is getting on my nerves, So any advice appreciated.

Neil C

[stef123]

im having similar issues and im very puzzled by it. when i let the revs return to normal idle it drops slightly then picks itself back up to 750rpm or there abouts. but if im using lights, heater etc it drops dramatically and the car shakes very slightly then returns to 750rpm.

my car is now on its 4th coil pack this year, when the last one was changed the battery was changed also as this is known to cause electrical gremlins. it lasted for 8 weeks but im back to square one again. ive tested the alternator output and its fine.

i can only think its an electrical issue that playing havoc with my coil pack but im f*cked if i know what it is. in the past ive changed the ICV(which did help) also checked thoroughly for vacuum leaks.

[artscot79]

im having similar issues and im very puzzled by it. when i let the revs return to normal idle it drops slightly then picks itself back up to 750rpm or there abouts. but if im using lights, heater etc it drops dramatically and the car shakes very slightly then returns to 750rpm.

my car is now on its 4th coil pack this year, when the last one was changed the battery was changed also as this is known to cause electrical gremlins. it lasted for 8 weeks but im back to square one again. ive tested the alternator output and its fine.

i can only think its an electrical issue that playing havoc with my coil pack but im f*cked if i know what it is. in the past ive changed the ICV(which did help) also checked thoroughly for vacuum leaks.

have you had the voltage regulator checked the focus is known to have weak earth points and doesnt like excessigve loads focus hacks has info on it it requires using heavy duty earth cable and upgrading them all the car shouldnt stall though the revs should drop but the violtage regulator will make it pick back up to anywhere between 680-750rpm use the dash diagnostics and go to the battery readout it will read 14.7 or so idling with no electrics then turn the electrics on 1 by 1 and watch it the voltage with everything on shouldnt drop below 12 if it does then voltage regulator or the alternator is a t fault if it stays at 12 or more they are fine also whatever the readout is when you use the gas the reading should increse

[stef123]

have you had the voltage regulator checked the focus is known to have weak earth points and doesnt like excessigve loads focus hacks has info on it it requires using heavy duty earth cable and upgrading them all the car shouldnt stall though the revs should drop but the violtage regulator will make it pick back up to anywhere between 680-750rpm use the dash diagnostics and go to the battery readout it will read 14.7 or so idling with no electrics then turn the electrics on 1 by 1 and watch it the voltage with everything on shouldnt drop below 12 if it does then voltage regulator or the alternator is a t fault if it stays at 12 or more they are fine also whatever the readout is when you use the gas the reading should increse

even under load the alternator voltage still remained quite high so i can only presume its ok.

i did consider making up some earth cables. from the battery to body and the battery to engine. atleast that way if any of my earths are weak i should have eliminated them.

engine running im seeing 14.4 volts, under loads im about 14v IIRC.

cheers for the suggestions so far.

[artscot79]

even under load the alternator voltage still remained quite high so i can only presume its ok.

i did consider making up some earth cables. from the battery to body and the battery to engine. atleast that way if any of my earths are weak i should have eliminated them.

engine running im seeing 14.4 volts, under loads im about 14v IIRC.

cheers for the suggestions so far.

try this site they explain the earth issue better than i its a well known problem especially if you have a big install etc it cant cope try the link http://www.focushacks.com/index.php?q=type...ce&ht=Audio / Video / In-Car-Entertainment

[mintalkin]

also check the battery terminals and get the battery drop tested.

[stef123]

i think to be fair the battery on my car should be fine, it is only 8 weeks old but...

i have just been out with the old multimeter and made an interesting discovery. i scratched a few bits of metal on the egine and took a reading between them and the battery. the lowest reading i got was nearly 40 ohms.

at the moment ive not got any crimps for 4awg cable although i do have the cable but ive got 2.5mm cable and crimps so i will use them for now and see if i can get this high resistance down.

[InstructorPiggy]

yeah, get some earth cable, do a good daisy chain around the bay, bodywork to engine and back again and then to battery!!

I did it with me colt once...cured a lot of ICE problems....and I had two batterys running and a capacitor!!

Check the loom by the aux belt too...the wiring sometimes rubbs through creating a bad earth.

:)

[stef123]

yeah, get some earth cable, do a good daisy chain around the bay, bodywork to engine and back again and then to battery!!

I did it with me colt once...cured a lot of ICE problems....and I had two batterys running and a capacitor!!

Check the loom by the aux belt too...the wiring sometimes rubbs through creating a bad earth.

:)

sounds like a plan, i will try that tomorow and check the wiring. atleast i will get rid of the high resistance lol.

do you think the high resistance/poor earth could be the killer of coil packs and also causing me to have an erratic idle for a second?

cheers

stef

[InstructorPiggy]

maybe...easy way to find out...and it aint that expensive!!

Gota get it sorted really, if you getting that high resistance and it finds its way to the ECU...ooooouch

[stef123]

maybe...easy way to find out...and it aint that expensive!!

Gota get it sorted really, if you getting that high resistance and it finds its way to the ECU...ooooouch

very true, the only problem is trying to find a good point to fit an earth to.

[Neilc]

im having similar issues and im very puzzled by it. when i let the revs return to normal idle it drops slightly then picks itself back up to 750rpm or there abouts. but if im using lights, heater etc it drops dramatically and the car shakes very slightly then returns to 750rpm.

my car is now on its 4th coil pack this year, when the last one was changed the battery was changed also as this is known to cause electrical gremlins. it lasted for 8 weeks but im back to square one again. ive tested the alternator output and its fine.

i can only think its an electrical issue that playing havoc with my coil pack but im f*cked if i know what it is. in the past ive changed the ICV(which did help) also checked thoroughly for vacuum leaks.

Hi Thanks for all the advice so far, i have been reading it all through, When you changed the coil pack did it cure the problem even if only temporarily?

Also what is the ICV which you say actually helped by being changed?

My voltage at the battery stays at about 14.7 even when everything is turned on so i dont think its the alternator.

Maybe we will get some more help from users later on

Regards

Neil

[InstructorPiggy]

make one...find a bolt or two on engine, remove, clean off area with wet/dry paper...body work plenty places you could rub away at, put bolt/nut/self tapper in...just ensure you seal it after to avoid rust :)

[stef123]

Hi Thanks for all the advice so far, i have been reading it all through, When you changed the coil pack did it cure the problem even if only temporarily?

Also what is the ICV which you say actually helped by being changed?

My voltage at the battery stays at about 14.7 even when everything is turned on so i dont think its the alternator.

Maybe we will get some more help from users later on

Regards

Neil

yes the coil pack did certainly help to begin with but it was either masking the original problem for a while or the original problem takes a bit of time to affect the coil pack.

the ICV controls the flow of air when the throttle is shut basically. Idle control valve.

my alternator is doing exactly the same as yours then really, load doesnt affect its output too much. so it looks like the alternators are ok then.

im going round to my garage tonight to knock up some earths and fit them on and see if i can stop this erratic idle and flickering headlights. earth faults can throw up the weirdest of symptoms at times so lets keep our fingers crossed.

make one...find a bolt or two on engine, remove, clean off area with wet/dry paper...body work plenty places you could rub away at, put bolt/nut/self tapper in...just ensure you seal it after to avoid rust :)

i will go hunt out my emery cloth and a file. im gonna fit an earth right on the bracket that secures the alternator and also atleast one more to the bodywork, anywhere else you recommend?

i might even use a set of jump leads first to see if it makes a difference before i go making holes or pulling bolts out.

cheers

stef

[stef123]

ok well a bit of an update.

ive been round at the garage most of the night doing some experimenting and testing.

it appeared that all my resistance readings from the battery to each earth point were about 40ohms, ive now fitted a new earth 'loop' and removed and cleaned up all the existing earths and managed to get the earth resistance down to 3ohms. i would have taken the car out for a little drive but the battery is flat.

now the major earth problem is the 2 earths situated at the side of the screenwash filler. now i dont know about anyone else but i usually soak these when filling up the screenwash.

hopefully this will help you aswell neil but i will be back on here tomorow morning after ive got the car started.

[InstructorPiggy]

remove those earths, emery cloth, then refit and spray (if you got some) with battery terminal spray, helps keep moisture out :)

great to hear ohms is down!!

did you pop extra earth to engine casing at all??

get some piccys :) and a test drive and report!!

[stef123]

remove those earths, emery cloth, then refit and spray (if you got some) with battery terminal spray, helps keep moisture out :)

great to hear ohms is down!!

did you pop extra earth to engine casing at all??

get some piccys :) and a test drive and report!!

i have cleaned up all the existing earths and refitted them.

ive got an extra earth from the battery to the alternator bracket, from there it goes to the bodywork and then to the cylinder head (rear)

also got one from the battery going to the main body earth point and then to another point on the body.

its all done with thin cable at the moment but as i know it works i will make up some new earth cables when im next at work. will use 6mm square rubber insulated cable.

will get some pics tomorow after i get it started up, hopefully all is well.

from 40ohms to 3ohms...thats just ridiculous? that extra 37 ohms must have been playing a vital part in my problems...surely that cant go unnoticed.

oh and i did hunt the battery terminal spray out earlier...the good old green gunge

[InstructorPiggy]

good man, seems like you got it under control...may reduce that ohms little more with better earth cable :)

well done...should make a difference :)

[stef123]

good man, seems like you got it under control...may reduce that ohms little more with better earth cable :)

well done...should make a difference :)

i sure hope so. the closer i can get it to 0 the better lol. thanks for your help so far mate :)

[stef123]

will it do any harm to remove the battery overnight so i can charge it? also will it do any damage to the battery charging it with a lead acid charger? its a lead calcium battery.

[InstructorPiggy]

will it do any harm to remove the battery overnight so i can charge it? also will it do any damage to the battery charging it with a lead acid charger? its a lead calcium battery.

don't think so, ensure you got ya radio code thingy...thats just a headache otherwise.

and always remove earth first, connect last.

Duno bout the charger....is it truly a specific charger for lead acid??

[stef123]

don't think so, ensure you got ya radio code thingy...thats just a headache otherwise.

and always remove earth first, connect last.

Duno bout the charger....is it truly a specific charger for lead acid??

no radio code to worry about, its an after market jobby.

ermm it was bought a few years ago for my lead acid batteries but i presume it only puts out about 13.5v or there about? just means it wont fully charge?

[InstructorPiggy]

no radio code to worry about, its an after market jobby.

ermm it was bought a few years ago for my lead acid batteries but i presume it only puts out about 13.5v or there about? just means it wont fully charge?

duno, I remember when just leaving the trade the garage spending a collasal amount on a special charge for the gel batteries!!....on ya own there!

[Neilc]

i think to be fair the battery on my car should be fine, it is only 8 weeks old but...

i have just been out with the old multimeter and made an interesting discovery. i scratched a few bits of metal on the egine and took a reading between them and the battery. the lowest reading i got was nearly 40 ohms.

at the moment ive not got any crimps for 4awg cable although i do have the cable but ive got 2.5mm cable and crimps so i will use them for now and see if i can get this high resistance down.

Stef When you did the earth readings and got the high ohms readings was that with the engine running?

ps all this help and advice is great lets hope we can find a cure for all of us and others as well

Neil

[stef123]

Stef When you did the earth readings and got the high ohms readings was that with the engine running?

ps all this help and advice is great lets hope we can find a cure for all of us and others as well

Neil

no with the engine turned off, with it running it just makes my meter give silly readings.

ok so from the battery to any point on the engine i now have 3 ohms which im very happy with.

but from the battery to points on the body under the bonnet im getting anything between 10 and 13 ohms. not sure if thats 'acceptable' or not but i cant seem to get it any lower.

also, when i have no load on the engine and i rev it and let it fall back to idle it does it without dropping and when i do it under load it still drops ever so slightly but its much better than it was.

getting there slowly.