What’s failed on my TDI

GaryJeffery

New member
Joined
Jun 23, 2018
Location
United Kingdom
TDI
1.9 TDI AWX
Hi all
New here so please forgive any ignorances :)
I have 2 1.9 TDI’s in my boat, both AWX engines from Passats.
On way back from a trip, one engine started behaving oddly, it seemed to lose a little power, I throttled up a bit to match rpms, then few seconds later revs rose as the power seemed to return, so I throttle down a little to match revs again (circa 3k rpm) this happened 2 or 3 times over a couple of minutes then the engine just died and won’t restart. No noises, no overheating or oil pressure probs, felt like fuel starvation.
In trying to diagnose the issue I have fitted a new fuel filter and bled through, no joy, had a spare crank sensor so fitted that still no joy. just cranks at a good speed but no start.
My thoughts are that it could be either electrical or mechanical, maybe the tandem pump? 109? Cam sensor? (Not sure that would stop it from starting tho) hoping someone will recognise the symptoms to point me in the right direction.
I don’t have the comms ports fitted in this installation, so can’t plug in a vagcom or similar. I am looking at getting to a breakers to pick one up and work out how to fit it. Can you plug in to the ECU directly?
FYI EGR is removed blanked off and deleted, vac circuit is just the basics for the turbo, no brake servo needed at sea! Foam conical air filter fitted just outside MAF with short intake to turbo side. ECU reprogged to 160 hp
Any pointers from the gurus most welcome.
If anyone interested, I can get some pics later of the install.
Best regards
Gary
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Without being able to communicate with the ECU, you are pretty much screwed. Pulling the DTC's (codes) from the ECU will tell you where to start troubleshooting.
 

babydoll

Well-known member
Joined
Feb 20, 2009
Location
wv
TDI
01 jetta 5 spd 01 golf 5 spd cruze diesel 9 spd auto 17
2001 jeeta tdi door locks

my 2001 jetta doors wont ;lock except pushing down on the button on top of door , remote wont lock them [ lights flash and u can hear relays clicking under the dash and signal and park lights flash ] but doors don't lock , I changed the door module and checked the wiring still don't work?
 

GaryJeffery

New member
Joined
Jun 23, 2018
Location
United Kingdom
TDI
1.9 TDI AWX
Problem Solved

Hi all
Thought I would post the solution for anyone who had the similar issue of loss of power intermittently before stopping and then not starting.

Turns out my Relay 219 was dodgy, after eliminating all other possibilities, I opened up the ECU box to check in there. All looked ok, I even unplugged and replaced all fuses checking for any cause. I have two engines in the boat, so to test relays I started swapping them from the running (starboard) side. 219 was first and it started up immediately.

Odd thing is that when I plugged the suspect relay back into the starboard engine, that fired up ok too! I had opened up the relay and had a good wiggle of the contacts etc so that may have cured it. I am getting a new spare, in case that suspect relay goes again under use.

Still planning to add in the diagnostic port in the near future, but it’s nice to know that the good old process of elimination still works ?
 
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