please can anyone help, as im loosing the plot

[mr rosher]

if anyone can help me i would be much appreciated, as im lost with this.
over the last few months my e280 started to idle very badly and would just die, then another time it was fine,
these are the things iv'e replaced over the last year or so,

bosch air mass,
lambda sensor,
charcoal canister,
rebuilt the wiring loom,
temperature sensor, the one for ECU,
air sensor, the small one that fits in the air intake,
new super bosch plugs,
new plug leads,
throttle body,
O.V.P.R,
a 2nd lambda sensor as the blink tester was telling me mine had gone,

last week i decided to take a few days of work and strip the wiring harness back again just to see if there was any problems. and no problems at all, all the joins were good ran a continuity check on every wire from each plug to the ECU plug and all good readings, refitted the harness but the blink tester was still telling me that i had air mass problems, so went and bought a new bosch one and fitted it, cleared the codes, run the car for say 5 mins rechecked for any codes and none, went for a run and as soon as i stopped she died, got back home and air mass code again, if i disconnect the air mass when on idle she will go through the gear box with out any problems idles at 650 rpm. and will idle at 650 rpm when in park, as soon as you reconnect the air mass the idle is very bad and within 20 secs she dies,
now i know that the air mass is linked with the O.V.P.R by a two pin plug
today i noticed that after about 5 mins of her running this O.V.P.R gets warm, does anyone know if this should happen or not. from what iv'e read on the forum you can check the O.V.P.R on pin 87 i think ? but when do you do this eg key on and not running / or with engine running, also which pin is 87 mine has no numbers by the pins.

thanks for any help on this, as im not sure where to go from here,

rod

 

[television]

What are the engine number please the first 6


Yes the OVP relay is coupled up to the control unit. there are three systems out there

You could always check the OVP relay and solder all of the connections

 

[BlackC55]

Check the wiring back to the engine control module from the air mass. You may have a short.

Wiggle the loom when the engine is running.

 

[mr rosher]

What are the engine number please the first 6


Yes the OVP relay is coupled up to the control unit. there are three systems out there

You could always check the OVP relay and solder all of the connections

hi malcolm thanks for replying, i was hoping to make the meet at beaulieu this year, and thank all you guys in person who's helped me over the last year, but the way things are going it looks like its going to be a no go.

any way forget that, now it sounds like im feeling sorry for myself,

sorry malcolm do you need the engine no, or chassie no,

you said in your post solder all of the connections, ? but would'nt this put live to earth, and how do you get the thing apart, it seems to be a sealed unit, as i said in my thread do these get warm as mine does.

once again thanks for the help you can give on this, its now getting to the point of giving up and breaking her, it will be a shame as its something so small causeing this, but as iv'e said in the past, with the engine rebuild, and the money iv'e spent on parts after parts its now running in to the £3200 bracket, and the missus is not happy with me, oh'well have to buy her ANOTHER pair of shoes, ha ha

 

[mr rosher]

Check the wiring back to the engine control module from the air mass. You may have a short.

Wiggle the loom when the engine is running.

thanks for replying blackC55,

i have checked the wiring from the air mass and its all linked in the harness that was rebuilt and then double checked last week by myself,
the wires on the sealed plug that fits the air mass looked fine i trimed them back very slowly from the bulkhead where they sit and all was fine untill i got to the plug its self, as the wires went in to the plug they were badly damaged. i decided to grind back the plug very slowly and see if they were touching but they wern't ? i think.

i don't know if you or someone els'e can help with this question, but if the wiring was at fault and its linked to the O.V.P.R which would go first / the air mass / or the O.V.P.R ?

thanks again for your help

rod

 

[jberks]

I have to say that given what you've spent, in both time and money and the problems you're having, however hard you try, you can never repair a loom fully. There are always going to be issues with shorts, earthing, tracking and breaks. You fix one bit and another will go, and it's not always obvious with small breaks that come and go with heat and movement. Even if you have continuity, it doesn't guarantee you have the correct resistance and it's resistance that most sensors use to communicate. A little corrosion and a few broken strands, and you have a perfect sensor sending the wrong information to the ecu. A meter is going to have a hard job showing it, especially given the disturbance you need to test it.
As you've already found, you'd repaired the loom, but found a new problem in the MAS plug. Fix that and there will still be others.

If it were mine, I'd bite the bullet and replace the loom.

 

[mr rosher]

I have to say that given what you've spent, in both time and money and the problems you're having, however hard you try, you can never repair a loom fully. There are always going to be issues with shorts, earthing, tracking and breaks. You fix one bit and another will go, and it's not always obvious with small breaks that come and go with heat and movement. Even if you have continuity, it doesn't guarantee you have the correct resistance and it's resistance that most sensors use to communicate. A little corrosion and a few broken strands, and you have a perfect sensor sending the wrong information to the ecu. A meter is going to have a hard job showing it, especially given the disturbance you need to test it.
As you've already found, you'd repaired the loom, but found a new problem in the MAS plug. Fix that and there will still be others.

If it were mine, I'd bite the bullet and replace the loom.

hi jberks, thanks for the reply, the wiring loom was'nt just cut and rejoined,

the E.C.U. plug was taken apart, and each wire on each pin was desoldered and resoldered with a new wire of the same grade and colour from the e.c.u. plug, to each and every plug, the only plugs that i could'nt get to the pins were, the air mass, throttle body, these were the then either cut in half very slowley by a stanly knife / or as the air mass i cut back the top to expose the wires and and pins then renewed each wire,

this job took just over 4 days, so every wire from the e.c.u plug to all the other plugs in line have been renewed, so the wiring loom is basicly new,

yes your right, i did replace the wires last time, but that was a cut and resolder, so this time i decided to do it right and take each plug apart no matter how long it took,

once again thanks for your reply

rod

 

[aussie]

mine was doing the same change yuor fuel filter