Erratic idiling when umder electrical load

[Neilc]

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.

Hi Just all morning cleaning all the existing earthing points as mentioned, also added a thick cable from the alternatot to the top suspension mount hopefully a good earthing point!! Also added a new earth cable from the battery to the other suspension point obviously if these are rubber mounted underneath then it will do nothing!!

Going out for a spin (Literally) later will report back this evening.

One thing I have noticed with mine is that no matter how long I let it tick over the rad cooling fan does not seem to kick in, maybe due the cold weather not sure really.

Keep up the good work

[stef123]

Hi Just all morning cleaning all the existing earthing points as mentioned, also added a thick cable from the alternatot to the top suspension mount hopefully a good earthing point!! Also added a new earth cable from the battery to the other suspension point obviously if these are rubber mounted underneath then it will do nothing!!

Going out for a spin (Literally) later will report back this evening.

One thing I have noticed with mine is that no matter how long I let it tick over the rad cooling fan does not seem to kick in, maybe due the cold weather not sure really.

Keep up the good work

if you have done the suspension mount then that should be a good earth point, the nut will hold your earth tight against the body so it doesnt matter if the strut is rubber mounted if you see what i mean. i have also done this on mine. presumably you did remove a bit of paint first? mine was painted under the nuts so i just scratched some of it away.

had a thought earlier though, i was checking the resistance with the battery still connected...oops. ive check all my earth point now with the battery disconnected and im getting between 0.1 and 0.4ohms so im good with that.

my radiator fan hasnt been on either and ive had the car idling for ages, i wouldnt worry about it. if the temp gauge starts going up and the fan doesnt cut in then i would worry.

i cant really road test at the moment as my coil pack is nackered and it plays up when the engine is under load so until i have that i cant drive the car.

cheers

stef

[InstructorPiggy]

don't wuz about fan...gets to 90degrees for the stat just to open....bet it won't get to that just idling in this weather!!!

well done with things...getting there...you may get worse resistance with bodywork...think of all the other things connected to bodywork!! Bodywork cold pick up resistance of things around too!!

Ensure you got doors/boot shut...as the earth on the doors for the interior lights will affect your reading :)

[Neilc]

don't wuz about fan...gets to 90degrees for the stat just to open....bet it won't get to that just idling in this weather!!!

well done with things...getting there...you may get worse resistance with bodywork...think of all the other things connected to bodywork!! Bodywork cold pick up resistance of things around too!!

Ensure you got doors/boot shut...as the earth on the doors for the interior lights will affect your reading :)

Went out for a drive yesterday afternoon and the news is not good if anything its worse, now it just cuts out when I let the revs die at junctions or in a queue.

Another mechanic has suggested the small sensor on the very front of the throttle body housing which he thinks is there to open the throttle butterfly valve very slightly and increase the revs when load is applied to the alternator and is controlled probably by the main ECU ( Gulp)

Going to look for one at the breakers and change it just to see!!!!

Lets keep trying

Neil

[stef123]

Went out for a drive yesterday afternoon and the news is not good if anything its worse, now it just cuts out when I let the revs die at junctions or in a queue.

Another mechanic has suggested the small sensor on the very front of the throttle body housing which he thinks is there to open the throttle butterfly valve very slightly and increase the revs when load is applied to the alternator and is controlled probably by the main ECU ( Gulp)

Going to look for one at the breakers and change it just to see!!!!

Lets keep trying

Neil

that part you are reffering to is the ICV - idle control valve

cheers

stef

[Neilc]

that part you are reffering to is the ICV - idle control valve

cheers

stef

Stef Surely the idle control valve is the silver cylinder thingy right next to the inlet manifold.with the wiring connector actually behind the inlet manifold

The piece I am on about is screwed directly on to the throttle body housing and held in by two srews with those funny heads!! or am I really confused

I have tried to add two photos No 1 is what I am trying to describe. No 2 is the ICV surely??

[stef123]

Stef Surely the idle control valve is the silver cylinder thingy right next to the inlet manifold.with the wiring connector actually behind the inlet manifold

The piece I am on about is screwed directly on to the throttle body housing and held in by two srews with those funny heads!! or am I really confused

I have tried to add two photos No 1 is what I am trying to describe. No 2 is the ICV surely??

first pic is TPS - throttle position sensor and second pic is indeed the ICV. The problem is more likely to be the ICV as when the butterfly is fully closed it regulates the amount of air that is allowed to bypass the butterfly and enter the inlet manifold. the TPS is kinda self explanatory.

also the 'funny' headed screws you reffer to are torx but i can remember what size im afraid.

[InstructorPiggy]

that part you are reffering to is the ICV - idle control valve

cheers

stef

but that doesnt control the butterfly...just opens a hole basically to adjust air flow...

[stef123]

but that doesnt control the butterfly...just opens a hole basically to adjust air flow...

i didnt really mean that it controls the butterfly, what i really meant was that instead of the butterfly opening, the icv allows air to bypass it... apart from the part of the description that said it opens the butteryfly, ICV fitted the bill for what he meant.

other than your throttle cable there is nothing that controls the butterfly.

sorry for the confusion ;)

[artscot79]

http://www.autoequipment.com.au/PicoScope/.../alternator.htm

have a look here the faults somewhere in the smart charge system remember the voltage from the alternator to the battery should drop after the cars had a run it shouldnt read 15v or 14.7 all the time so im thinking that if it is then this effects the way the ecm regulates the idle control dependant on the load on the system it sounds like the ecm for whatever reason isnt telling the icv what to do hence the car stalls.

Smart charging enables the voltage supply from the alternator to vary depending on the temperature of the battery's electrolyte. It has been proven that a cold battery will respond better to a higher voltage than a hot battery, which responds better to a slightly lower voltage. The temperature of the electrolyte is calculated by monitoring the air intake temperature when the engine was last stopped and the current intake air temperature. From these two datum points, the battery's temperature can now be calculated and the appropriate charge sent to the battery.

The charging system employed on the Ford Focus is unlike any other charging system that is currently in production.

Ford utilise what is termed a 'smart charge' system. With a conventional charging system the battery is charged at a voltage that is determined by the voltage regulator, with all the electrical load being drawn from the alternator fed battery.

Smart charging enables the voltage supply from the alternator to vary depending on the temperature of the battery's electrolyte. It has been proven that a cold battery will respond better to a higher voltage than a hot battery, which responds better to a slightly lower voltage. The temperature of the electrolyte is calculated by monitoring the air intake temperature when the engine was last stopped and the current intake air temperature. From these two datum points, the battery's temperature can now be calculated and the appropriate charge sent to the battery.

The alternator will have two connections to the Engine Management Module (ECM), these are to monitor and control the output. This monitoring also allows the Idle Speed Control Valve (ISCV) to be operated when high electrical demands are seen when the engine is at idle. The ECM will also controls the engine run relay, which only allow circuits with a high current demand to be activated when the alternator is charging, until which point the components remain inactive.

The ECM is now responsible for switching off the dashboard mounted 'charging light'. When starting the engine with a conventional alternator, the unit is activated as soon as the ignition is switched on, a 'smart charging' system will only initiate the alternator once the engine has started. This action avoids an unnecessary waste of voltage on a vehicle with a discharged battery and also avoids the extra effort involved in cranking an engine with an operational alternator.

[stef123]

to be honest, i know how the smart charge system works and i doubt if this is my problem. the link you put up says the alternator maintains a voltage of 13.5-15v which with the readings im getting is perfectly normal. i will admit ive never checked the voltage after a good run though

also my ECU is obviously responding to load put on the engine as when i put any load on it at idle it picks back up to normal revs after half a second.

im still getting a bit of the old famous zetec 'lift off misfire' though, when i lift my foot off the gas it appears to misfire and be slightly jerky so ive yet to work out why this is happening.

cheers

stef

EDIT: when i think about it, its not all the time that my engine revs drop dramatically when returning to idle, i wonder if i have a temp sensor or something on the way out?

i believe the IAT sensor is part of the MAP sensor?

[Neilc]

http://www.autoequipment.com.au/PicoScope/.../alternator.htm

have a look here the faults somewhere in the smart charge system remember the voltage from the alternator to the battery should drop after the cars had a run it shouldnt read 15v or 14.7 all the time so im thinking that if it is then this effects the way the ecm regulates the idle control dependant on the load on the system it sounds like the ecm for whatever reason isnt telling the icv what to do hence the car stalls.

Smart charging enables the voltage supply from the alternator to vary depending on the temperature of the battery's electrolyte. It has been proven that a cold battery will respond better to a higher voltage than a hot battery, which responds better to a slightly lower voltage. The temperature of the electrolyte is calculated by monitoring the air intake temperature when the engine was last stopped and the current intake air temperature. From these two datum points, the battery's temperature can now be calculated and the appropriate charge sent to the battery.

The charging system employed on the Ford Focus is unlike any other charging system that is currently in production.

Ford utilise what is termed a 'smart charge' system. With a conventional charging system the battery is charged at a voltage that is determined by the voltage regulator, with all the electrical load being drawn from the alternator fed battery.

Smart charging enables the voltage supply from the alternator to vary depending on the temperature of the battery's electrolyte. It has been proven that a cold battery will respond better to a higher voltage than a hot battery, which responds better to a slightly lower voltage. The temperature of the electrolyte is calculated by monitoring the air intake temperature when the engine was last stopped and the current intake air temperature. From these two datum points, the battery's temperature can now be calculated and the appropriate charge sent to the battery.

The alternator will have two connections to the Engine Management Module (ECM), these are to monitor and control the output. This monitoring also allows the Idle Speed Control Valve (ISCV) to be operated when high electrical demands are seen when the engine is at idle. The ECM will also controls the engine run relay, which only allow circuits with a high current demand to be activated when the alternator is charging, until which point the components remain inactive.

The ECM is now responsible for switching off the dashboard mounted 'charging light'. When starting the engine with a conventional alternator, the unit is activated as soon as the ignition is switched on, a 'smart charging' system will only initiate the alternator once the engine has started. This action avoids an unnecessary waste of voltage on a vehicle with a discharged battery and also avoids the extra effort involved in cranking an engine with an operational alternator.

Ok I sort of understand the principles behind what you are saying, but could the fault be within the alternator (is a swop worth trying) or is the fault somewhere else (Possibly battery) I am booked in a Ford Diagnostic on Wed and would like to get it sorted before if it's possible

Neil 07790697078

[artscot79]

Ok I sort of understand the principles behind what you are saying, but could the fault be within the alternator (is a swop worth trying) or is the fault somewhere else (Possibly battery) I am booked in a Ford Diagnostic on Wed and would like to get it sorted before if it's possible

Neil 07790697078

if im honest i know ford isnt cheap but the diagnostics is the best way there are so many things that are linked sensor wise and a diagnostics would be cheaper than replacing part after part i think the diagnostics is the best bet mate that way you will know if its summat stupid or even just a copuple of sensors let us know how you get on

[Neilc]

if im honest i know ford isnt cheap but the diagnostics is the best way there are so many things that are linked sensor wise and a diagnostics would be cheaper than replacing part after part i think the diagnostics is the best bet mate that way you will know if its summat stupid or even just a copuple of sensors let us know how you get on

Ok I only asked because my mechanic has a alternator from a previous focus engine and has offered to fit it tomorrow morn and I just wondered if it was worth a shot and I have a spare battery in the garage and was just wondering.........

[stef123]

Ok I only asked because my mechanic has a alternator from a previous focus engine and has offered to fit it tomorrow morn and I just wondered if it was worth a shot and I have a spare battery in the garage and was just wondering.........

originally i thought the cause of my problems was becuase of a duff battery but obviously not. the result of your diagnostic test will be very interesting.

how much is the diagnostics going to set you back? if it does throw up some reasons then i will definetly pay to have it done on mine!

if your going to change the battery for another one make sure its a lead calcium one otherwise you will do damage.

[Neilc]

originally i thought the cause of my problems was becuase of a duff battery but obviously not. the result of your diagnostic test will be very interesting.

how much is the diagnostics going to set you back? if it does throw up some reasons then i will definetly pay to have it done on mine!

if your going to change the battery for another one make sure its a lead calcium one otherwise you will do damage.

Hi diagnostics is £70 something plus the dreaded. surely any car battery is lead acid!!

[stef123]

Hi diagnostics is £70 something plus the dreaded. surely any car battery is lead acid!!

not all cars im afraid,

if you charge a lead acid as you would a lead calcium you will burst it(charging voltage is too high). but if you charge a lead calcium as you would a lead acid you will only charge it to about 50%(charging voltage too low). the very reason i would stay clear of anyone in Halfords trying to sell me a battery, what do they know? buy this one its more expensive...

as far as i know any ford with the smart charge system needs a lead calcium battery.

well i might just need to get the dagnostics done, will wait and see what your result is.

[Neilc]

not all cars im afraid,

if you charge a lead acid as you would a lead calcium you will burst it(charging voltage is too high). but if you charge a lead calcium as you would a lead acid you will only charge it to about 50%(charging voltage too low). the very reason i would stay clear of anyone in halfords trying to sell me a battery, what do they know? buy this one its more expensive...

as far as i know any ford with the smart charge system needs a lead calcium battery.

well i might just need to get the dagnostics done, will wait and see what your result is.

Oh Why are cars so complicated, I know the battery is second hand in mine, so how do i tell which type it is?

running out of time to find a cure fast!!!

[stef123]

Oh Why are cars so complicated, I know the battery is second hand in mine, so how do i tell which type it is?

running out of time to find a cure fast!!!

if its lasted a while then id say its a lead calcium? if not then the high charging voltage gasses the electrolyte and the battery lasts a very short time if it doesnt burst.

it will have PbCA on it possibly? where as a lead acid will just have Pb? not entirely sure as i cant remember what my old and new battery had on them.

[Matt_focus_zetec]

Brillant thread so far whats the out comes i have a similar problem check this out as this si what i have tried so far but am definatly going up to maplins tmra to buy some earth cable

http://www.fordownersclub.com/forums/index...amp;#entry57184

my previous thread

Cheers

Matt

[stef123]

Brillant thread so far whats the out comes i have a similar problem check this out as this si what i have tried so far but am definatly going up to maplins tmra to buy some earth cable

http://www.fordownersclub.com/forums/index...amp;#entry57184

my previous thread

Cheers

Matt

hey matt,

i just posted a reply to your thread a few minutes ago. so far my car isnt much better than it was but im now suspecting the map/iat sensor.

now that my engine and chassis are well earthed i can begin poking about so as i said in your thread, my new code reader should be here tomorow and it will allow me to view and record live data so i will be checking out the map and iat sensor and seeing whats what if anything. will be interesting though.

cheers

stef

[stef123]

well my new code reader/scanner came today so ive been out trying it on the car and have found some interesting stuff.

now when returning to idle my car always dips then the revs pick up again. while it does this the TP sensor is at 19.2% but if i bring it back down to idle at 20% it idles perfectly! if that makes sense? so looks like i need a new TP.

MAP and IAT sensor reading appear to be normal. unplugging the sensor makes the car rev higher and also run like sh1te.

normal readings (at idle) are 31C give or take for temp and 23? Kpa for pressure.

unplugged readings are -40C and 125Kpa. so all appears fine?

the lambda sensors do follow each other, most of the time. so i guess these are ok.

the TP sensor is part number 1071403 and its £59.58 inc vat from ford.

and it just so happens that i have a spare sensor here, will change it over and see what happens.

[Neilc]

Hi diagnostics is £70 something plus the dreaded. surely any car battery is lead acid!!

Hi just a quick follow up on the Ford Diagostics yesterday

Cost £75, inc vat

NO REASON FOR PROBLEM FOUND, only faults codes listed were for things I had changed whilst trying to solve the problem, so they have erased them and sent me away to drive for a few days and then bring it back and have the codes read again to see if anything has reappeared and yes they will recharge me for the second diagnostics but with some discount probably 10%.

I got to talk to the mechanic who was very helpfull and said that the battery was not actually the correct one for the car it's got an 063 type and it should have an 065 type as a min, so I have been a bought a second hand 075 from my local breakers and fitted it this morning.

Test driving this afternoon fingers crossed I will let you all know how things go!!!

ps I asked him about bad earth's and sort circuits etc and he said mine was not showing any evidence at all.

Keep up the good work and we will solve this eventually

Neil

[Neilc]

Brillant thread so far whats the out comes i have a similar problem check this out as this si what i have tried so far but am definatly going up to maplins tmra to buy some earth cable

http://www.fordownersclub.com/forums/index...amp;#entry57184

my previous thread

Cheers

Matt

Hi Matt welcome to the thread, I have just added another piece to Stef, have a read and we will see what happens later today!!

Happy new year

Neil

[stef123]

thats an interesting one neil. shame its costing a fortune for the diagnostics though.

i have now changed the throttle position sensor and have changed the idle reading from 19.2 to 20% so that has helped a little but still not great. it did appear to work when i first tried it but it seems more of a hit or miss.

ive been recording data and playing it back and it appears one of my lambda sensors could be out? at most times they follow each other but there are times when one sensor goes to (for example) 0.651v while the other one stays very low at 0.115v. but i am seeing anything between 0.1 and 0.7v between the two. im sure a lambda sensor is meant to read between 0.2 and 0.8v?

hopefully we will be getting some good results soon and solve the problem!