2.1TD doesn't start(starter works)

[hyvarinent]

Hello,

this is my first post to this forum. I'am from Finland so sorry for my bad english

I own 1998 model 406 grandwagon with 2.1TD engine. Problems started during driving. Every now and then tachometer "died", there was power loss and K-light (transistor) blinked. In three days it happend about 20 times. Then I cleaned some sensor plugs close to filter. After that it didn't start at all until next morning everything was ok. I drove 1000km without any problems. Then bliking started again I shuted down the engine and waited to netx mornig after that it hasn't started at all.
One thing what I noticed when it doesn't start the K-light is not glowing when turning electricity on. So glow light is ok, airbag light is ok but k-light is missing.

I managed to find electrical drawings to lucas ECU but if here is someone who can tell reasons why that light could be missing I would be very thankfull!!

Cincerely Tuomas

[lozz]

My guess, crank sensor, icouid be wrong,
best off getting car read for fault codes to confirm tho,

[hyvarinent]

I read codes when it was "blinking" and there was no any. Everything was ok. That's why I'm wondering if some 12V is missing from ECU. But if it's crank sensor would it be in fault codes and can it make that transistor light to not glow when turning electricity on?

-Tuomas-

[midsdaz]

Have u tryed cracking the injectors to make sure there is fuel getting to them coz my crank sensor was coming up as faulty but my car still started with a bit of throttle

[lozz]

Transistor light?
Do you Mean Glow plug light ?

Sorry for confusion,
check you have 12v going to the glow plugs

[hyvarinent]

No not glow blug, k-light is few lights to left from glow light. It's abit like K letter but really it's transistor mark.

here is picture:
so this normaly goes on when turning the key now it doesn't

-Tuomas-

[midsdaz]

Engine management light ye should be on when u turn the ignition light on

[lozz]

fuse gone perhaps,

try fuse 12

fuses.jpg

[hyvarinent]

yes it shoud but it isn't. 12V goes from fuse to some sensor then to K-light and then to another sensor and then to ECU. problem is that I don't know what those sensors are so measurement is abit hard.

I have check fuses and I think it's something else because it did this same thing, "dead" for one night and then worked like a sharm about 1000km then it was blinking during drive and then it won't work, fuses don't repair them selves

I check that crank sensor today and measure same wirings too...

-Tuomas-

[marius]

Hello, I'm also new to this site, but find it very interesting.

Is the motor control system made so that engine stops if crank sensor is faulty ?
Or is it made so that if crank sensor is faulty the engine cannot be started ?

I had problems recently with starting my 1997 406 2.1td after not using it for 1,5 months. I thought it might be the fuel cut off valve at the fuel pump that did not open. It probably was just poor fuel supply due to air leaking into fuel feed pipe. I cured it by using start gas for diesel engines. I sprayed start gas into the air intake pipe from the air filter while starting. It worked well. After that I just used the handoperated prime pumping bulge in the engine room to pump up fuel pressure to the fuel pump. The reason I tried to use start gas was that someone told me that even if the cut off solenoid valve does not open while starting, it will open if the engine where already running. If this is the case perhaps the it is the same case for the crank sensor ?

Just a tip for trying to start difficult engine - please some more experienced meber can verify or not.

Best regards

[hyvarinent]

I found the problem but I don't understand it.Car is running again

If I measure the doublerelay with now key turned it shows +12V on pin 14 but when I trun the key it drops to 1V??? Voltage comes directly from F5. Odd thing is that when pin 14 drops to 1V also 4,5,6 and 13 goes to 1V. that is what I don't understand.

Pin 14 is in coil side and 4,5,6, and 13 in relay side output. pins 8 and 15 are relay side input and there is allways +12V.

I hope someone can tell me why that relay is working like that?I tried different relay and same thing...or they both are broken

Here is doublerelay picture

-Tuomas-

[steve_earwig]

Can you post a link for the rest of that diagram? From what you're saying it's more accurate than the one I'm looking at here: http://www.autoelectric.ru/auto/peugeot/406/p8c/p8c.htm

Anyway, it sounds to me like there is a bad connection further back: with no load you are seeing the full 12 volts but when everything is turned on the voltage drops out. What happens to the voltage at fuse 5? (you might want to check that this is the right fuse first...)

[hyvarinent]

it's little bit different than your picture. What I measured yesterday I think my version is what is in my car but I have to check that.

Yeah I was also thinking that when there is load it drops but other voltages are mixing this hole thing up

here is hole picture what I get from finnish peugeot dealer

[steve_earwig]

Don't let these other voltages confuse you:

Odd thing is that when pin 14 drops to 1V also 4,5,6 and 13 goes to 1V.

Because, when the relay is closed, pins 4, 5, 6, and 13 are connected to pin 14, so if pin 14 reads 1 volt then so will they.
[/quote]...pins 8 and 15 are relay side input and there is allways +12V. [/quote]Because they're fed off of a different fuse (is that 25?)

As above, check what the voltage does at fuse 5 (after checking it is the right fuse in case both of our diagrams are wrong )