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407 Won't start after head De-coke

6K views 61 replies 7 participants last post by  Nelix 
#1 ·
Hi All

Some of you may remember me posting my woe's relating to my 1.6 HDi 55 plate 407, it wouldn't rev over 1500 rpm, loads of black smoke/soot out of the exhaust.... blah blah blah.

Well, it's been sat in the back yard for almost a year and I decided to have another go at it.

After looking at live data (In Graph form) and using a boroscope, the live data indicated an airflow issue and the boroscope identified carbon build up on the inlet valves. Soooo, off with its head.

Removed the head and had to use a rubber hammer to tap the exhaust valves out as they were tight, I had a friend take it into his work to de-coke it and give it a damn good clean, the valves were also cleaned along with all other components associated with the internal workings of the head, it was also discovered that the 2 cams were not timed correctly, they were 1 tooth out!!!!!! not sure how that happened.

Anyway!! the head was put back on the car and everything reconnected and plugged in.

Now......... with great expectations I turned the key and it spun...and spun....and spun.......and spun, not totally unexpected due to everything that had been done to it so we tried again and it spun.......and spun.......... it tried to start.........then spun.....and spun.......and spun. We left it for a while and tried again and it spun...........You get the idea :(

So we hooked up the tow bar and thought we would try and bump it whilst towing it, pulled it down the road and it SSSSSsssppppppppuuuuuuuunnnnnnnnnnnn for a good few hundred yards, More than once but still would not start.

Plugged PP in and no fault codes (Initially there was but these were cleared and have not returned) live data shows fuel pressure to be good, air flow to be good, basically, Everything appears good. :confused:

SO, What do I do next????

Just as a side note, whilst the head was off I poured a little diesel in each cylinder and left it in overnight. Upon checking the next morning, Cylinders 2, 3 and 4 were empty, Cylinder 1 still had some in. Could this be an indication that the rings/cylinder walls are worn?

I have ordered a Cylinder compression tester for diesel's which should be with me after the weekend and will report back with the results.

It is work doing a leak off test of the injectors?

Any tips or clues would be greatly appreciated.


Cheers

Nelix
 
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#3 ·
Now there's something I have not checked.

I also don't remember hearing the chime at any time yesterday to inform me that the key was in the ignition, not sure if that only happens 'After' turning the engine off but as it won't start it might not chime..... I believe "Trustme" will put me right on that one.

Keep them coming.

I'm at work today :( but will have another check when I get home).

Thanks
 
#5 ·
Just a quick update, I tried the key but the battery in the key was dead so would not sync up, got a new battery and managed to sync the key so it beeps now when left in the ignition:D, tried to start it but the car battery was too flat so I've currently got it on charge and will report back tomorrow once it's had a good charge.

Not much of an update, but an update non the less :)
 
#7 ·
I know the key battery would not stop it starting but I thought it would be needed to sync the key.

The main thing is that I now know that the key has not lost its code, I just need to try and start it with a good battery now
 
#10 ·
Dont bother checking compression as it will be low anyway and you will then think the engine is duff

It will be low because its cold and it will be low because its not run for so long

Go back on planet got to parameters 1 post up the cranking readings you see let us see what your getting

Also check ecu status in parameters to be SURE the ecu is unlocking.
 
#15 ·
Dont bother checking compression as it will be low anyway and you will then think the engine is duff

It will be low because its cold and it will be low because its not run for so long
I was just going to make sure they all had relatively the same compression, as per the results of the diesel in cylinder test, not sure how conclusive that is, cylinder 1 would appear to be holding better than the others so would use 1 as the ref cylinder and see if the other 3 were relatively the same.
 
#11 ·
I checked the ECU status and it's showing as not locked.

I some readings whilst cranking, and they all appear to be fine, or at least close to reference values.

I'll give it a go today though and post them here I case I missed something.
 
#13 · (Edited)
Apparently, i'm restricted to 4 images per post so here's a few more:


DAP 1



DAP 2



ECU is Definitely unlocked:



I have noticed that the DAP is showing an 11% load which seems a little high, wouldn't have thought it would stop the car from starting.

I also have some live data in Graph format if you need it
 
#16 ·
As trustme says its not turning fast enough to open the injectors everything seems ok except cranking speed.

Most of the parameters wont matter as far as starting is concerned it needs to see a good cranking speed of at least 250rpm
fuel pressure matching reference
cam and crank sync

These are all that matters airflow glowplugs etc can be ignored

you have 2 of the 3 so it really should go even with low compression it will go with a tow but sometimes they need towed a decent distance in gear to wake them up as the injectors can get clogged with sitting idle.
 
#17 ·
I could have sworn I saw it cranking at over 300 rpm

I'll check the graphs to confirm speeds

Does anyone know how to view the saved data without having to plug the interface into the car, PP start but I can't access the "Previously Saved Data" option due to it not being plugged into the car.

Cheers
 
#18 ·
Try looking in C:\APP\OUTILREP\TRACE\MEMO\

should have trace files saved as XML documents (can be opened in word or browser)
 
#20 ·
if compression was low then the engine would spin faster as it would have less strain for the starter motor,

what is the battery voltage before cranking and while cranking
check and clean the battery connections
check and clean engine and main body earth
check and clean starter connections
 
#21 ·
I bought a Cat C 2009 Clio 6 months ago, wouldn't start despite airbag light extinguishing, using Clip determined no impact detected, cleared codes, all ecu's and CAN network say we're OK but still won't go!
Eventually got a wiring diagram from a forum member and swopped the injection relay in the UPC for the adjacent heated rear screen relay and it burst into life. Think the problem was down to lack of use sitting in the outside in the salvage yard and Copart.
As your car has been standing so long I wonder if this could be the cause of her not starting.
Get some one else to turn the key while you tap the engine fusebox and ecu and wiggle the wiring to try and trace any poor connection. Would be worth getting a noid lamp to confirm injectors are firing.
 

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#23 ·
I'm looking at Copart at the moment :)


Going by the correction figures i would be confident to say the injectors are NOT firing as they are at rest figures
I thought this but thought it might just be due to it cranking and would not register correction figure until it actually started but if that is not the case, i'll investigate further.

It's not going to be for a couple of days as I am back at work for 2 day shifts so can't look at this again until Friday but I will keep you informed.
 
#27 ·
Mind yourself at Copart, it's easy to loose your shirt. Prior to the Clio I bought I looked at the same model that looked absolutely fine save for a crease just behind the rear window. I went to see it and discovered that the bumper was held on with tie wraps as the crumpled rear end had not been pulled out just a replacement tailgate and bumper fitted. It had the yard staff at Copart fooled who had described the car as having all over damage. Once we discovered the true extent the auction was halted and restarted with the car properly described.
Main problem is you can't see who is selling the car, the only way to find out is to ring the branch who will usually tell you whether it is an insurance co or private seller.
 
#29 ·
You just need to know what your looking at i have only ever had 1 bad buy but even then it was just a case of it had more wrong than i had expected the biggest issue some fall foul of is the buyer fees they can add a lot to the final price :)
 
#30 ·
I've made note of the buyer fee's and always keep them in mind. I also tend to put my max bid in and don't watch the auction, if I did I would end up bidding more than I wanted to or even more than it was worth :grinning:
 
#31 ·
Well the Noid Lights arrived so I checked the injectors, 2 of them anyway, and looks like there is no pulse as the noid light does not flash.

So my next question is, where is the injector relay?



After the relay, what else would you recommend to check?

The battery seemed a little low again so I am going to take it and get it tested, It's still under guarantee so will get a new one if it's goosed.

Cheers
 
#32 ·
As stated in an earlier post injectors will not be triggered by ECU below around 200 rpm and 250 bar fuel pressure. Based on your screen shots cranking speed is to low for injectors to be triggered
 
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