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Fuel system failure (petrol)

55K views 126 replies 57 participants last post by  Jerry 
#1 ·
Due to the recreation of the forum by back up my post from the end of last week has disappeared, so here follows a summary in the hope it helps others.

At the end of last week I returned to my ZTT KV6 to find that it wouldn't start. Plenty of cranking, but no firing.

As an AA member I used their services, and between the patrol mans knowledge and what I had picked up on this forum, the fault was quickly diagnosed as the fuel filter / regulator assembly having partially unscrewed. This causes loss of pressure in the fuel system and hence failure to start.

The fault was fixed by the roadside in approx 30 minutes and I was on my way home. The main problem with a roadside fix is that AA rules say the tank must be half full or less to avoid fuel spillage.

Anyway, the AA had to use the old hammer and chisel routine to loosen the locking ring and re-tighten it as no special tool was available on the van. This meant it was only classed as a temporary repair, and I was advised to get it overchecked and retightened by a dealer.

Having seen how easy the job was I thought I would do it myself instead, and also see if I could better lock the two halves of the assembly together.

So I tackled the job on Saturday, and here is the lowdown for anyone with the same problem:-

* Just remember that we are talking about dealing with an open topped fuel tank inside a car here, so no naked lights / sparks / power tools and loads of ventilation, plus avoidance of spillage *

1) Remove the rear seat squab (Pull the front upwards to unclip then push backwards to release at rear. It will probably require a grovel underneath the raised squab to help release the rear.)

2) Remove the body cover plate over the filter / regulator assembly (That is the access plate on the left hand side behind the passenger seat [UK]. The access plate on the right hand [UK driver] side covers the similar installation for the fuel pump.)

3) Release any trapped pressure in the fuel system by depressing the schrader valve (under a trendy coloured dust cap by the throttle body under the bonnet)

4) Detach the push fit fuel pipe by pushing in the green retainer clip and tie back out of the way.

5) Make up a simple metal tool to remove the locking ring, and detach it. (mine was actually made from a couple of stainless steel wall ties bolted together, but whatever you use, it must be capable of the 38Nm installation torque)

6) Partially remove the filter regulator assembly, and twist both halves firmly back together (The joint is immediately above the stainless steel reinforcing band)

7) Reassemble by reversing the process, and ensuring that the seal between the tank and assembly is correctly installed and the locking ring torqued to 38Nm.

I have tried to prevent further occurence of the fault by pinning the joint in place with a couple of self tappers, but only time will tell if it works...

Anyway, it's not a bad job at all if you are mechanically minded and have the basics such as torque wrench and socket set.
 

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#28 ·
Interesting thread - thanks.

My ZT190 was serviced on Tuesday (which I assume included a fuel filter change) and then failed to start Thursday evening.

Could be a coincidence, but without me saying anything the AA man suggested the new filter hadn't been screwed in fully.

I'll see what the dealer says....

Phil
 
#30 ·
less luck here. AA came out again this morning and he knew about the loose filter problem. Tightened it up but no better - suggested a faulty pump (alhtough this was replaced last year)

Took it to the local dealer and they've found a faulty fuel regulator (which is part of the filter assembly, I believe) £60 for a new one.

Phil
 
#31 ·
Phil Raby said:
Interesting thread - thanks.

My ZT190 was serviced on Tuesday (which I assume included a fuel filter change) and then failed to start Thursday evening.
What's the name of that new TV program/....Don't get me started.... (no pun intended).....but how often do we get that....take your motor in for work to be done and it comes out with another fault...drives me insane %^&(&$£"####!
 
#33 ·
Phil Raby said:
My ZT190 was serviced on Tuesday (which I assume included a fuel filter change) and then failed to start Thursday evening.

Phil
Yes, although the fuel filter is serviceable / replaceable, the maintenance schedule I have for ZT never mentions changing it. I guess it must be sized to last for vehicle life in normal conditions.

I'm glad the thread is still helping you all. It's often the simplest things like this that cause the most grief! It's interesting to look at the workshop manual (RAVE) which actually shows an entirely different filter housing that clips together rather than screwing together. I guess that explains why earlier cars didn't seem to have this problem! Wonderful thing continuous improvement.
 
#34 ·
Well, just got home after being stuck on the side of the A34 for 3 hours.

I was driving along happily with a 1/4 tank of fuel showing when the engine just died. Luckily I was able to coast into a layby.

I called the AA (again) and they took 3 hours to get to me!

I explained what had happened last week and we looked at the fuel regulator and pump, all seemed OK. Then he checked his computer and found a note suggesting that ZT fuel gauges can stick, so he put in a gallon of petrol and the engine started!

He followed me to a filling station where it took about £60 to fill up, suggesting a very empty tank. Even after filling right up the gauge only read half full.

So, it seems the monkeys at the garage have managed to mess up the fuel sender. More time wasted tomorrow going back there... :cry:

Phil
 
#35 ·
The AA guy who rescued me some time back also mentioned a fuel guage sticking problem, although you're the first I've actually heard of. His first attack was to put a gallon of fuel in the tank, although that turned out not to be the cause in my case.
 
#37 ·
Mmmmmmmm
I too was driving along happily, at 90mph on CC in central France last month, with a 1/4 tank of (diesel) fuel showing when the engine started coughing, I immediately dipped the clutch and coasted to a halt by which time the engine had stopped.
I had flashed my mate who was driving in front and who also managed to stop.
The engine would not respond to two or three cranks so we had a discussion on what to do (i.e. Call AA 5 Star) #$%^&*!.
Anyway before doing that I tried another crank which started the engine!
Carried on at vastly reduced rate of knots for about 10K with the tank still showing quarter full and computer confirming the range left (on the wonderful French motorways you are never further away than 40K to a service area), stopped for diesel and it took 55 litres in a 56 litre tank!
Conclusion at the time was that 90mph combined with an up hill gradient caused fuel starvation.
But now I'm thinking maybe a stuck fuel gauge was the problem.
Does the computer take it's readings from the fuel gauge? I suppose it must.
 
#39 ·
Dave Turbo said:
ZT has a 65 litre tank. :D
Yes the computer uses fuel left and calculates by the fuel its using and give a figure to show 'range'.
That's interesting DT....are you quoting from experience or the book?...because the singular most disappointing thing for me from first ownership of the ZT-T, was the lack of range.
I quoted a 56 litre tank because 55 litres is the maximum I have ever got into it when the red light is on and the computer is telling me I am running on fresh air!
What is more (and I have posted this before), under normal circumstances if I run the tank down to the red light the car will normally run OK but takes a lot of cranking to start (always starts instantly otherwise).

All this this tells me that both the gauge and computer on my car are not lying to me in that when the red light comes on, the tank is effectively empty.
However if you are right (I don't doubt your figures DT) and the ZT-T like the ZT has a 65 litre tank then in my car at least, something like 9 or 10 litres are there for the ride!

I filled up yesterday right to the neck and have done 46mls since, the range is now reading 489.
At a regular and checked 42mpg doing the sums on that equates to an 'effective' tank size of less than 58 litres! so the 56 litres I work on is about right for my car.

I WILL now check to see if I am carrying 9 litres of fuel ballast......any comments forum members?
I would be most interested if anyone can confirm in fact that they do get 63 or 64 litres into their ZT-T tank.
If so, I have a problem Houston!
 
#40 ·
Rob Cavell said:
However if you are right (I don't doubt your figures DT) and the ZT-T like the ZT has a 65 litre tank then in my car at least, something like 9 or 10 litres are there for the ride!

I filled up yesterday right to the neck and have done 46mls since, the range is now reading 489.
At a regular and checked 42mpg doing the sums on that equates to an 'effective' tank size of less than 58 litres! so the 56 litres I work on is about right for my car.

I WILL now check to see if I am carrying 9 litres of fuel ballast......any comments forum members?
I would be most interested if anyone can confirm in fact that they do get 63 or 64 litres into their ZT-T tank.
If so, I have a problem Houston!
The manual says "Fuel Capacity (usable) - 65L". The most I've got into mine is 62L, and the fuel guage had been showing "0" for a few miles.
 
#41 ·
Slint said:
The manual says "Fuel Capacity (usable) - 65L". The most I've got into mine is 62L, and the fuel gauge had been showing "0" for a few miles.
Thanks Slint, the most likely cause I supposed is to check the tank unit to see how far down it is reaching.
I won't bust a gut though as my previous disappointment with the range has somewhat eased now the car is doing 42mph regularly against when before, for the first 3-4k miles it was returning only 34mpg!
 
#43 ·
Sorry I didn't see this earlier guys, there's a technical note from X-Part floating around in the last few weeks detailing this exact repair (very common apparently) anyway they have designed a clip to do this exact job:
Fuel Module Retaining Clip- 1 off required WJC000230, will cost you about a fiver, cheers

Keith
 
#44 ·
ZS105 said:
Sorry I didn't see this earlier guys, there's a technical note from X-Part floating around in the last few weeks detailing this exact repair (very common apparently) anyway they have designed a clip to do this exact job:
Fuel Module Retaining Clip- 1 off required WJC000230, will cost you about a fiver, cheers

Keith

this from the dealers? I've used a selftapper.

do any of the BMWs suffer from this failure as its a BMW part?

they may have 'deleted' the clip to be spiteful!! - Surely not :D
 
#45 ·
I too have experienced the the fuel filter unit separating which was repaired by my local garage (I didn't look at the forum before calling the AA). :cry: Whilst the car now runs it takes a good 5-6 seconds to start once I turn the starter motor. Investigation shows that fuel pressure does not remain in the system. Indeed there is no fuel at the engine at startup. Therefore the fuel pump has to re-prime the system each time I start. I compensate for this by letting the fuel pump prime at Key Position 2 each time I start the vehicle.

I consulted the garage who conducted the repair and they stated that there was a non-return valve somewhere in the fuel system to prevent the fuel draining back down from the engine. Is this the case? If so, where is it situated?

I have also re-examined the fuel filter assy following the destructions earlier in this thread, but it appears to be together and I don't really want to split it again!

Any other suggestions?!?!?! :confused:
 
#46 ·
Mine went today. I'd just been giving it some supercharged beans and then phut(!). Coasting to a halt. I'd read this post and looked at the piccies, so it didn't take long to diagnose and fix.

Later I went to fit self-tappers and dismantled again. I managed to disturb the O-ring that joins the two halves of the housing, so even reassembled it was bleeding pressure. Took three goes to get it right, but it is sorted now.

Well done ZTTMAN for the write up.
 
#47 ·
Dave Turbo said:
this from the dealers? I've used a selftapper.

do any of the BMWs suffer from this failure as its a BMW part?

they may have 'deleted' the clip to be spiteful!! - Surely not :D
Is it a BMW or Bosch part?

Serice fix items tend to be expensive - to pay for the research into finding the fix, I guess!
 
#48 ·
srbhiscock said:
Whilst the car now runs it takes a good 5-6 seconds to start once I turn the starter motor.
I've managed to do this to mine from the second reassembly yesterday.

I think this is down to the o-ring between the two halves of the filter assembly not being seated correctly. This results in a slow bleed of pressure. You still get enough pressure to run, but there is a constant slight leak. At rest, the filter must drain back. I'm going to have another go at it later.

I've been up to the elbow in petrol trying to fix this. Good job the V8 drinks so much fuel. Next time I disassemble the tank will be near empty.
 
#49 ·
Whilst the car now runs it takes a good 5-6 seconds to start once I turn the starter motor.
I have now fixed this on my car.

I consulted the garage who conducted the repair and they stated that there was a non-return valve somewhere in the fuel system to prevent the fuel draining back down from the engine.
The problem is that the reassembled fuel filter has one of its seals slightly displaced, causing a pressure leak.

I have also re-examined the fuel filter assy following the destructions earlier in this thread, but it appears to be together and I don't really want to split it again!
To get this fixed you will have to split it again. To get the sealing O-ring to slip into place, you need a can of nylon and rubber spray lube.

Disconnect the clipped on fuel pipe from the top (with no pressure in the system teher should be no fuel leak). Split the filter apart: rotate the top anti-clockwise and then ease the two parts away from each other, working against the friction of the o-rings. Once fully apart, you will see the fuel filter element. The thin ~80mm diameter o-ring is probably wedged down the side of the filter element; fish this out and position it on the cylindrical section of the top filter housing section, leaving it ~1-2mm away from the shoulder that will finally locate it. Spray with nylon and rubber lube. Spray the small o-ring in the centre of the unit as well. Reassemble. It should go together easier than it came apart.

Prime the engine and start - it may take a few seconds to purge the air first time. Leave it for 5-10 minutes and then see if it starts on the button. :roll:
 
#50 ·
Hi guys. I own a ZS 180 and have had the same sort of symptoms. A new pump was fitted. 8 weeks later did it again. It's been into my local dealer and 3 weeks later and after endless claims of no fault found they changed the pump as they say it's gone again. They've changed it and seemed ok until the following morning driving home from work it started to go again. Managed to get it to local garage and fuelled up and seemed ok. It has done it since but notas bad.

The only thing is that the inspection cover is opposite side ti where pump is fitted. Tank has to be removed.

Does anyone know if the setup is the same? If so could do with some giudance.
I'm sure you'll understand when I say "I don't trust the car anymore!" I love the thing when it runs fine as drives great and handles superb. I don't want to get rid of it as I love it but when the trust fades it's hard to think otherwise. (God I sound like my ex girlfriend!! :lol: )

Please help guys as I want to save this relationship!! :lol:
 
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