406 won't start mystery

Mandalinci · Post by **Mandalinci** » Fri Jun 08, 2007 4:43 pm

Hi Everyone. Am new to the forum as I've just bought a 98 406 Executive 2.0 Turbo (petrol) after running bullet proof 405's for years. Car was starting and running perfect when I bought it. 2 days later it won't start. The only possible interference has been some water splashing on the engine during a car wash. Dash lights are all on, car turns over but there is no spark at the plugs. Have changed the coil pack but still no spark. Don't really know where to go next. Any ideas guys? Also does anyone know which,if any, of the 3 wires (red,blue,green) going to the coil pack multi pin should be live with the ignition on. Sorry to be a bit long winded but I really don't know what to try next.
Decent donation to this site if I can sort this problem

Pyros6546 · Post by **Pyros6546** » Fri Jun 08, 2007 8:34 pm

this sounds like a job for SUPER jameslxtd.
well as the engine bay dried out, have you
checked the pugs themseves, or any visible
wiring. try round the starter seeing as its not
kicking up. although the starter might just be
sticking. if u can get to it give the starter
a good whack then try to start it

jameslxdt · Post by **jameslxdt** » Fri Jun 08, 2007 9:10 pm

its the TDC sensor

Mandalinci · Post by **Mandalinci** » Fri Jun 08, 2007 9:47 pm

Many thanks for the replys guys.
Engine bay completely dry. Starter is turning over fine. Just no spark at the plugs. Would the TDC sensor (where is it by the way?) just pack up like that? Would it result in no spark?

jameslxdt · Post by **jameslxdt** » Fri Jun 08, 2007 9:54 pm

even the slightest bit of water is enough to kill the TDC sensor, its black with a cable attached to it, on top of the gearbox, and is held in with one 10mm bolt, it tells the engine ecu when to fire the coils, so if it dies you will have no spark, you will also find the rev counter doesnt work when you try and start, a new one is about £22 from pug

Harshan · Post by **Harshan** » Sat Jun 09, 2007 11:05 am

wish it's not the ECU

Mandalinci · Post by **Mandalinci** » Sat Jun 09, 2007 1:44 pm

Thanks loads. Have removed TDC sensor but can't for the life of me find where the wire goes to. It seems to go off behind the engine somewhere but I can't see where. I know I'm pushing my luck but can you help?
Graham

robbie123 · Post by **robbie123** » Mon Jun 11, 2007 9:45 pm

If you can't see where the cable goes, just cut the wires and resolder the wires ontot he new one maybe?

Bit of a bodge but one that works and works well. Hope you get it sorted

jameslxdt · Post by **jameslxdt** » Mon Jun 11, 2007 9:53 pm

NOOOOOOOOO
not on the tdc sensor, it has a screened cable and will pick up interference and never run
the plug is easy to find, you may have the wrong sensor

robbie123 · Post by **robbie123** » Tue Jun 12, 2007 5:37 pm

Whoops! Ignore me

Can't be too hard to find...

Mandalinci · Post by **Mandalinci** » Tue Jun 12, 2007 7:03 pm

Have got the new sensor coming tomorrow. Couldn't locate the (plug) end of the sensor as I was laying on my back trying to see up around the back of the engine without really knowing where the plug is located. Didn't really want to go rooting round blind .Hopefully the new one will show me how long the lead is which should make locating the old plug easier.Fingers are now firmly crossed. Does anyone know if failure of this sensor would cut off the fuel supply? Plugs are bone dry even after turning the car over for a minute. Would have expected to at least smell fuel but no smell at all.

jameslxdt · Post by **jameslxdt** » Tue Jun 12, 2007 7:40 pm

the 2.0 8v turbo runs simetaneous injection, and uses the TDC sensor signal to trigger the injectors as well as the coils, so you will have no fuel as the injectors wont open or spark

Mandalinci · Post by **Mandalinci** » Wed Jun 13, 2007 4:28 pm

Fitted the new crank sensor. Now got to the stage where there is a good spark but car will not start. Doesn't seem to be any fuel getting through (plugs are bone dry even after engine has turned over for ages) I can't believe this car was starting and running perfect 6 days ago. Think I'll just admit defeat. A million thanks for your help guys.