Earth Point

[mechsmurf 0]

does anybody know where earth point p121c is on car (haynes)

[welshpug 1,657]

not offhand, what wires go to it?

[GLPoomobile 958]

not offhand, what wires go to it?

 

Wire M3, it goes from the instrument cluster and it is the only thing earthed at that point according to the diagram.

 

Edit: I've gone off half cocked again! Wires M1 and M2 from the fuse board go there as does M27A from the heater control unit.

 

I would therefore suggest that it's likely to be in the vicinty of the fuse board.

Edited January 6, 2008 by GLPoomobile

[welshpug 1,657]

aaah if thats the case then IIRC its on the steering column bracket, I saw an earth point with only a few yellow wires on it earlier this week

[mechsmurf 0]

i have faint illumination of my coolant temp light and stop light also fan speed varys when it likes all these wires go to this point will check the connections on column tomorrow

 

lights have only started illuminating since i reconnected reverse light switch unless this is coinsidence

 

also where is diag plug located

 

many thanks

[welshpug 1,657]

it doesn't have one unless its a late car running motronic.

[mechsmurf 0]

oh right

 

also have hard starting probs will fire up first time but will then cut out have too keep reving till warm and its fine have adjusted idle at min so its ok when cold but then idles at 1500

 

also have got mayo oil that keeps blocking throttle and vac advance but headgasket is not blown

[mechsmurf 0]

also when cold car will start first time and run for roughly 15 secs at idle then die

 

any ideas

[pug_ham 244 3 Cars]

Clean the throttle body, AFM & all intake system / breather pipes to clear the mayo including the idle air bypass in the throttle body (& the idle screw) & set it up once everything is cleaned again.

 

Also check your vacuum capsule pipe is fitted & the capsule works.

 

A lot of 205 GTi's need a little help to get them to idle properly when cold but if the SAD is working & all pipes are clean once its set up properly you shouldn't need to.

 

Graham.

[mechsmurf 0]

i had a quick play with it yesterday ichanged the tachy relay but no difference then changed the sad still no difference

 

i noticed that the two identical sensors on back of engine (coolant temp and something else i believe) were mixed up

 

runs alot better now but i have to leave the pipe that goes from the oil filler to the throttle body off as when connected get this horrible squeel

 

sounds like vac unit near distributer are these hard to change or need properly setting up when touched

[pug_ham 244 3 Cars]

The vac unit is easy to change, its held to the dizzy body by two screws but easiest to change with the dizzy off the head because you need to hook the end back on inside the dizzy for it to work the advance weights.

 

It sounds odd that you have to leave the hose from the filler cap off or you get a horrible squeal though.

 

Graham.

[mechsmurf 0]

it is weird it wont seem to idle with it off when cold but if i do connect it it just squeels but if i rev car it will go awy untill its back to idle

 

but if i gun it to get it warm it will just go away untill next cold start

 

what does that vac unit actually do (noise definatly from this area)

 

also after swapping sensors around oil temp dont seem to move (is this one of the sensors i swapped)

[pug_ham 244 3 Cars]

Oil temp takes a while to move, usually at least ten minutes imo but sometimes more at this time of year but it depends how hard you drive it from cold. The sensor for the oil temp sender is in the back of the sump so definately not one of the two sensors you swapped around.

 

The vacuum advance adjusts the internals of the dizzy when under high load to give better pick up & economy. It certainly shouldn't be the cause of a sqealing in the engine bay though because there isn't that much to it.

 

Graham.

[mechsmurf 0]

oh right any ideas of what could be squeeling as the noise is definatly coming from that area

 

seems like it is clearing up though whatevere it is , just squeels when its getting warm but not as bad as the other day

 

would i be best just to leave the hose off and get a breather filter put on the end of the pipe

[pug_ham 244 3 Cars]

Remote diagnosis on an odd engine bay noise source is virtually impossible, does it change with the clutch in or out?

 

Find out what the problems is & leave the hose connected.

 

Have you tried cleaning out all the breather pipes etc & throttle body / AFM yet in an attempt to get it running better & rid it of the mayo? The hole in the top of the throttle body is very small (<1mm iirc) so it gets blocked very easily.

 

Graham.

[mechsmurf 0]

have cleaned out all pipes and noise went away for a few days but came back again think its clogging up again

 

and dont change with clutch

[Tom Fenton 1,542]

I'd hazard a guess that the squealing noise is air being pulled through a hole or split in the diagphram inside the vacuum advance module, and the amount being pulled through at idle is enough to just make it resonate and squeal. I've picked my new one of these up today from the main dealer so will be fitting it next opportunity I have. Mine does not squeal but then the rubber inside could be completely deterioated.

[mechsmurf 0]

just out of interest why are you changing the vac advance ie whats the problem with yours

[Tom Fenton 1,542]

The rubber diagphram splits meaning it doesn't advance the timing. Its a common fault, do a search you'll find lots of posts.

[mechsmurf 0]

thanks very much

[mechsmurf 0]

i went down to see nick at shenpar yesterday and i queried him about the squeel he said he had the same thing on his 106 he said its pressure build up to the cam cover he said that the next time it does it to pull the dipstick out a few mil as this cured his

 

but typically it has not done it since

 

also i checked the earth point on the steering coloumn but these are not the wires for the dash clocks or the fan blower

 

does anybody know where the earth points are