TS Fuel Rail - is it "Dumb"

Started by Citroënbender, November 05, 2017, 11:11:05 AM

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Citroënbender

A question; I can't resolve this by external inspection. 

Is the TS fuel rail wholly passive, as in just a labyrinthine tube with one inlet, four outlets and a test port? Or, does it have a non-return regulator or anti-drain valve under the crimped end cap where the test port is located?

I couldn't see any evidence of a pressure rating stamped on said end-cap, so my leaning is towards a passive structure. 

The manual 147 stopped suddenly at idle the other day, then after a bit re-started and ran for a few metres, thought maybe another flaky sender but after adding $50 to nearly brim the tank it still did this.  No faults logged pre-stalling; all the errors were from unexpected stop (mainly relating to lack of a coherent CAS pulse).  p.s. All the usual suspects (belts, alternator, battery, fuses etc) checked and fine.  So, if the fuel rail is out of consideration it would likely be the supply module...

bazzbazz

Have you disconnected the fuel hose attached to the fuel rail to see if you are getting supply of fuel? The pump itself may be U/S, even if you can hear it turning over in the tank it may not be pumping fuel down the line.

Just a thought.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

Citroënbender

#2
G'day Bazz,

Not tried anything yet; rail pressures, timed delivery volume, supply and earth at tank all merit a look before dropping $200 on a new unit.

A further question has come up.  This car has the earlier type (pre 2002) fuel supply module, any idea what is the actual difference in the pump and fuel feed line? I have a feed line from the '05 TS I parted out, so that could readily be installed, and the later pumps are appreciably cheaper (when both are Bosch in Bosch boxes - not Bosch in an Alfa box). 

bazzbazz

#3
I am just taking a guess here, but in later models of 156s the diameter of the fuel pump locking ring and the crown of the pump are different diameters to earlier models, it is probably the same with the 147s.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

Citroënbender

#4
No sweat, I'll get to grips with it and post up whatever I can find in the flesh.  :)

Might shout myself the Facom DM.J lockring tool, it's a fine piece of kit.

(Not this one!)

bazzbazz

I wonder what accessories are available to go with that model?   ;D
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

Citroënbender

#6
LOL, probably best if I don't dig myself a bigger hole.

After re-creating the fault today, I tested the electrical supply to my iffy pump; all good.  So either the nonreturn valve in the pump is leaking or the pressure reg is stuffed. 

Have established the fuel pump differences, they are obvious once you compare! The early one has a straight coupling and a horizontal outlet pipe, while the later one has a vertical outlet pipe and an elbow on the coupling. To replace the pipe, one has to drop the tank.

Note in the attached images, the later pump is misaligned. That's how I received it (and typical of why I don't have high regard for cars with "full dealer service history"). Also the nylon inserts to hold the cover screws have changed between years.

Citroënbender

It must be Bush Week... Flaky CAS seems the culprit. No visible tacho pulse on the dash now and staggering along.

Fuel pump/supply data for the public record:
5 litres free flowing delivery in 2.5 minutes, equals 120 litres per hour
Gauge pressure (ABV brand workshop EFI test kit) 51 PSI (3.5 Bar) "dead headed" stable for ten minutes with pump relay hotwired.
Line pressure loss after ten minutes pump off only 6 PSI, the remaining 45 pounds pressure is plenty good enough.

Assuming the sensor fixes it, I'll post a wrap accordingly.

bazzbazz

#8
Quote from: Citroënbender on November 06, 2017, 07:42:09 PM
It must be Bush Week... Flaky CAS seems the culprit.

Are you referring to Camshaft Sensor?

Sorry, I didn't realise in your original post you were referring to camshaft sensor failure, if so I would have mentioned that as being a passive Hall effect type sensor its original failure message would not have been part of the failures caused by engine stopping but would have been the cause.

My bad, was half asleep when I read your original post.   ::)

DOH!

On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

Citroënbender

No, the crank angle sensor is apparently open circuit. I'd seen the lack of signal coherence in the fault logs, but I've also found this gets logged at the "tail" of an unrelated failure that causes the motor to stop (like, running out of fuel).

I'm simply not used to these failing, it occasionally happens on the 2.0HDi Pug/Cit motors but the rest of my Frogs have been faultless on this part. 

bazzbazz

Well in the 147s its usually the magnet deteriorating due to heat, and when they start to go car stops when hot, engine cools down cars starts again.

For it to be open circuit its most likely just un unlucky broken wire.  :(
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

Citroënbender

New sensor from EAI (aftermarket Calorstat/Vernet brand) and all is well again.

Arse of a job to replace! Pulled the flexi pipe down after disconnecting from the rear cat and removed the hanger bracket near the bottom motor mount to get an arm in there. When fishing the new lead up, wished I had tied a pull string to the old one when I yanked it out. All clipped back like the factory did it, hope it lasts OK.