ZT not starting.. urgent help required!

[rikk]

Hello,
My MG ZT CDTi has decided it doesn't want to start. It's probably something i've done. I was checking the plenum drain hole, which had some debris in it but nothing too bad, certainly no water. Wish i'd left it alone now!

Anyway now the car won't start. Everything seems to work ok .. but when cranking it just does't start. It was working perfectly fine this morning before i checked the plenum. However i've had a good look at the wiring and nothing appears damaged, and everything is plugged in.

Presumably it's not getting fuel? Any ideas which specific things in that area I should check? If I can't fix it is there anyone in this area (NW Leics, near ashby) that could help? I use the car to get to work so am in trouble if i can't get it working asap!

thankyou :-)

[rikk]

Actually.. just been out to check again and the car started. Panic over. Sort of. Because now I don't know why it wasn't starting before, or why it's just started now. So am a bit worried that I might go somewhere and then it will refuse to start. Would be useful to know which wires to check if it won't start.

Also, when in that area I noticed a small plug with two pins that isn't plugged in to anything. Not sure what it's for, maybe an optional extra i don't have on this car? It has a red and a black wire, coming out of a loom in the corner near the passenger side wing in the plenum area.

[rikk]

Stopped working again.. i put the covers back and again something must have got disturbed. Definitely something iffy.. need to find out what it is and fix asap..

[rikk]

I think it might be the plug on the top of the under bonnet fuel pump.. after i wiggled that a bit then it started... i may have knocked it when removing the plenum cover. Not absolutely sure though, but i've cleaned the connectors in the fuel pump plug as best i can and put a bit of copper grease on. Still worried though. I'm going to run TOAF on it to see if it shows any error codes.

[rikk]

TOAF shows a 1260 pre supply pressure montitoring error .. Error not present.. zero RPM. Though from what i've read thats likely to be a red herring as it is a common error?

[Yorkshire GOC]

Things that come to mind

Crank sensor -does the tachograph needle move when your turn her over ? If not that points to a crank sensor fault - easy to see next time if she fails to start.

However on a diesel i would also consider injector leak back issues causing intermittent starting issues /stalling issues - you would need to carry out an injector leak back test using the "milk bottle" kit.

Finally after the above 2 is your fuel tank full if less than a third full a failing intank fuel pump can cause intermittent starting problems:shrug:

[COLVERT]

Things that come to mind

Crank sensor -does the tachograph needle move when your turn her over ? If not that points to a crank sensor fault - easy to see next time if she fails to start.

However on a diesel i would also consider injector leak back issues causing intermittent starting issues /stalling issues - you would need to carry out an injector leak back test using the "milk bottle" kit.

Finally after the above 2 is your fuel tank full if less than a third full a failing intank fuel pump can cause intermittent starting problems:shrug:

I think you must mean CAM sensor.

[richw]

does the tachograph needle move when your turn her over ? If not that points to a crank sensor fault - easy to see next time if she fails to start.

I have read this in a few places. When I turn the key to start my V6, the rev counter doesn't move at all until the engine actually fires, and it goes straight to about 1000 rpm. It normally starts OK.

Should the needle move a bit as the starter is turning the engine? Or is it a weird diesel thing?!

Sent from my Redmi 4X using Tapatalk

[trikey]

Do you have the oil light illuminated when you turn the ign on?

[patrolman pete]

Does the under bonnet pump run with the ignition on ? If not give it a tap with the handle of a screwdriver and see if it runs then try to start the engine. This has caught a few diesel owners out !

[trikey]

If not give it a tap with the handle of a screwdriver

Or your steel toecapped boot a la Marinabrian style :D

[patrolman pete]

Or your steel toecapped boot a la Marinabrian style :D

LOL ! I can just imagine it ! :D If in doubt ,give it a clout !

[marinabrian]

LOL ! I can just imagine it ! :D If in doubt ,give it a clout !

It got me off the hard shoulder of the M1 though :cool:

[rikk]

Thanks for the replies.. if it happens again i will look at the tacho and oil pressure.. could be a cam/crank sensor .. could be a strange coincidence, as did seem like it was due to what i'd done. On this car the ECU isn't in a proper plastic box, it is wrapped in bubble wrap and cable tied to the bracket! It was like this since i got the car a couple of years ago, and i did obtain the correct plastic box for it but never got around to fitting. So the plenum are is a bit messy with wiring and bubble wrap..

This morning i'd been out in the car, got back and decided to check the plenum hole. Took the cover off and removed some stuff from the hole, but it wasn't blocked, so no water build up. I put the covers back, and tried to start the car to go out a few minutes later and it just cranked but wouldn't start. So I assumed i'd maybe disturbed something. But having checked the wiring nothing looked damaged, loose or out of place. Then i tried to start it and it did start. Then i put the covers back.. and again it didn't start. A few minutes later after checking it over again it fired up. Currently working but i've no idea what caused it not to start. Fingers crossed it works ok tomorrow!

[rikk]

The car did run and start okay today but did some strange things.. showed a "brake fault" error, and the ATC went strange as well.. it was on Auto then when I pressed the button the clear the windscreen the whole ATC turned off.. ?! .. not sure if that could be because there are problems with the main ECU?..

[stevestrat]

Has the ECU got wet at any point? Diesel ECUs are not well sealed like the petrol models and are susceptible to water damage, especially as there's no housing. Even if its dry now there could be some corrosion going due to a previous incident,

[COLVERT]

You said in your post that the ECU had bubble wrap around it.
This suggests there might have been water problems for the previous owner.---:eek:

Could be that any corrosion has now started to effect the electrics on the car. Might need opening up to have a look inside.

[rikk]

Sorry for slow reply.. the car has been fine since this incident (i did panic a bit when it wouldn't start as i haven't time to deal with the hassle of a non starting car at the moment!) .. however i will get the ECU checked and fit it in the proper plastic box as soon as possible.

Just one more question.. I bought have a new cam position sensor recently and thought it might be a good idea to fit it to rule that out as an issue (and is an easy job). The part number is NSC100891. However while there seems to be only one type (part number) of sensor listed for this car.. when i took the old one out its a different shape.. it is all black and the part that fits inside is thinner than the new one (which is light grey).. the new one has the same electrical plug but won't fit in the hole. Was there different types? This is an 03 ZT CDTI.

many thanks