Fuel system failure (petrol)

[ZTTMAN]

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.

[markus]

Excellent post.

Does anyone know if the fuel tank/filter/pump set-up is the same for the V8s?

[MGmonkey]

It’s almost the same the pipe work is slightly different in the tank.

[markus]

I may do a "pre-emptive strike" on mine. It seems one hell of a common problem on these cars and I dread being stranded in the middle of nowhere on the A9 on a cold winters night.

[TimH]

Good write up Zttman

How long did it take? Did it all go back together okay?

[sparkes]

ZTTMAN

If you are ever near Redditch, Drop me a PM. I owe you drink or two!

My Monogram'ed ZTT 190+ failed to start after 2 weeks away and after reading this I found the problem and was able to fix it myself

Thanks

Steve

[Rob Cavell]

MMMmmm...your post has got me thinking, my Diesel ZT-T always plays up on starting when the fuel is (very) low, very long cranking.
Previously this has not surprised me for obvious reasons but now I'm wondering!!!
Any comments from the Diesel buffs out there? (yes I do know it's not a good idea to run the fuel very low but)......

[Big Blue]

Looks like ZTTMAN is doing well for drinks - I owe you too - another MGZT fixed thanks to your photos and description - you were better than the AA, and you never saw the car! Cheers mate.

[ZTTMAN]

Glad I was able to help chaps. Thats what these forums are all about! In answer to an earlier question I reckon about one hour is the norm to do the job, although it depends what you have to hand for "special tool" manufacture.

[Ex-Member_A]

Yeah well done for that!!

I no longer have a 75/ZT but when I do, I am sure it will come in handy.

This thread is now a good place to point people who have a little bit of spanner knowledge and have a fuelling issue with a 75/ZT.

Matt.

[Marcus]

Managed to find this thread after reading your comments on the V8 forum 'she's dead'. I always thought that it was only the V8's that had this problem, and that the V8 tank was a unique saddle tank, having to clear the prop shaft. Furthermore I thought that it had 2 fuel pumps, one to pump from one side of the saddle to the other, then one to pump forward to the engine.

It would appear that my understanding was wrong, and if I had have viewed your thread before or had access to the internet I could have saved a small fortune - circa £500!!!

As already pointed out, superb post that would not be amiss in a Haynes manuel.

Cheers.

M

[Gas-Axe]

Might be an idea for those who have saved £££'s to donate a little to the running of the site, perhaps?

Just a thought.

[Marcus]

Great idea, already putting £20-30 in via PayPal.

[ZTTMAN]

I had a chat yesterday with a one of the senior service technicians that used to be at Edwards of Stratford. Not surprisingly, he was well aware of the problem of the filter module unscrewing itself.

It seems I was psychic as the fix they had been using was as per the first post in this thread:- Two self tappers vertically into the joint face as per my photo. He reckons they had no further failures once this had been done.

I just hope he is right...

It might be worth a preemptive strike for any of you handy with tools?

[markus]

Yep, I'm giving it a go next week and will be putting in 2 self-tappers for peace of minds sake.

I shall be bodging up the special tool out of a cornflakes packet and a squeezy bottle in the best Blue Peter tradition.

It'll be just the heater hose to worry about then ........

[butlerpj]

As the famous Mr Burns would say.. Excellent!!

Friday night went to see the parents.. 00:00 came and I went to go home, turned the car and nothing.... was working fine...

Borrowed m'dads car to go home and returned on Saturday morning to look at the problem.

Remembered reading your post so printed off and started on the job of looking.. After removing the seat and cover there it was... The filter in two parts so I put it back together and fired first time.. Hardest part of the job was putting the bl**dy seat back... the back backets are a right pain.

Job done and Hip Hip Hooray to ZTTMAN!!!!!!

[Dave Turbo]

Minw was fine and working, but took it out at weekend to put a self tapper in it so it doesn't unscrew itself!!

One thing to note is, the rubber seal came out with the unit and this needs to be placed back in the tank before the filter is pressed back in, I tried for about 15mins trying to squash the filter back in with the seal ontop of the tank rather than having it sat in place around the tank hole rim. Plus I found a wide blade screwdriver was sufficient for removal and refit of the locking ring.

Also put some tweeters in the false tweeter holes in the rear doors!!

[DavidJ]

Can anyone confirm if the Fuel Filter for the Diesel ZT is in the same location? I ask as mine was supposed to have been changed during it's service, yet I am sure the rear seat has not been taken out - I have the MGR Seat cover fitted - and it is exactly as it was when the car went in for a service - i.e. 11mths on and somewhat skew wiff, not recently re fitted!

[Rincewind]

Originally Posted by DavidJ

Can anyone confirm if the Fuel Filter for the Diesel ZT is in the same location? I ask as mine was supposed to have been changed during it's service, yet I am sure the rear seat has not been taken out - I have the MGR Seat cover fitted - and it is exactly as it was when the car went in for a service - i.e. 11mths on and somewhat skew wiff, not recently re fitted!

Fuel filter for the diesel is located at the back of the engine bay on the outer bulkhead to the right (as you're looking at it). It's a big (normally) silver cannister, pipes off, unscrew it, re-fit is reversal and manually prime it. There is no need to take the rear seat out to change the filter (as it 'ain't there!).

[Mattl]

Manually prime it?

[Rincewind]

Originally Posted by Mattl

Manually prime it?

only if you're fitting a new diesel fuel filter does it require a manual prime. Not on petrols.

[Mattl]

how do you manually prime it? thought it was self bleeding.

[Rincewind]

Hum, you pump the little hand pump/bulb to get the diesel in. That's how L series is primed, it should be similar with the M47 but now I'm starting to question myself now! I'll check.

[redlakie]

Thanks guys! Brilliant Article - Local garage couldn't get me in until Wednesday - Really stuffed until I read this page ... One thing, i initially didn't twist the two halves back together and it still failed miserably ... Pondered on the issue and nearly resigned myself to the Dealer fix £££, re-read the instructions - twisted the two halves and hey presto!!!!! Brilliant, Brilliant, Brilliant!!!!!!! (Must stop saying Brilliant!) Cheers again.
Den

[NJRule]

Another success for ZTTMAN !

I have just had the same problem with my 10 month old ZT120. Sure enough, the problem turned out to be the filter housing unscrewing.

Fortunately for me, I read this forum before getting the RAC man to tow me to a garage !

Cheers Mate !

[Lobby]

Can't believe how useful these sites are. Came home from work the other night no problems. Went to go work the next day, car wouldn't start. I have an associate who happened to know the MD of the company who supplied the programming for the engine management systems for MG. He very kindly came out to try and help (huge thanks for that!) His software could not pick up a problem, though we did feel the fuel was there but low pressure.

ZTTMAN has saved a huge headache, many thanks.

[TimH]

Good being part of a collective isn't it.

Whats that famous saying from our great leader. Resistance is futile, you will be assimilated.

Welcome dude.

[Phil Raby]

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

[Lobby]

just finished repair. Fired up fist time. Am converted to these sites without doubt.

[Phil Raby]

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

[Rob Cavell]

Originally Posted by Phil Raby

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 %^&(&$£"####!

[Phil Raby]

Originally Posted by Rob Cavell

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 %^&(&$£"####!

lol! to be fair, they hadn't touched the filter or regulator, so I guess it's just coincidence.

[ZTTMAN]

Originally Posted by Phil Raby

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.

[Phil Raby]

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...

Phil

[ZTTMAN]

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.