Fuel Filter

dave-b · Unread post by **dave-b** » 21 Jul 2003, 19:13

Im still having problems with my '91 ZX 1.9i (petrol)
I was just wondering what type of problems I would have if the fuel filter was blocked.

AndersDK · Unread post by **AndersDK** » 21 Jul 2003, 20:32

Any engine running with a blocked fuel filter would have problems keeping up rev's on load after a short while.
The filter rarely cloggs finitely - but restricts fuel supply more or less.

dave-b · Unread post by **dave-b** » 23 Jul 2003, 05:17

Mine is losing power begins to misfire if i turn ignition off its fine again for a while ....

Unread post by **alan s** » 23 Jul 2003, 08:11

That sound electrical to me; like a dodgy ignition switch or a relay with a set of corroded contacts.
What's everybody else think??
Alan S

wrinklet1 · Unread post by **wrinklet1** » 23 Jul 2003, 12:32

Hi Dave, Just an idea, have you checked that the breather isnt blocked on your petrol cap? I once had a (Don't laugh) <b>LADA</b>gini and it also worked ok, then it would loose power, cough and misfire. Once I removed the petrol cap it worked ok and once the cap was removed I could hear a sucking noise as the air went in.
Just give it a try,you never know and it wont cost a penny.
Good luck
Paul

jeremy · Unread post by **jeremy** » 24 Jul 2003, 00:17

From your second post the problem might still be fuel filter but i think its unlikely. as Anders says the filter is unlikely to completely block but will restrict flow, a little at first but gradually getting worse.
this restriction will generally show up under circumstances of maximum fuel consumption - cold starting and rapid acceleration. I should imagine it happens quicker wiuth fuel injection than with carburrettors where the float chamber will tend to delay the effect. So if when driven very gently your car is normal but splutters when you accelerate and is slow - then that could be fuel filter.
Otherwise - electrical. - start by having a good look and see if anything looks dirty or corroded and clean it up before getting more involved.
Jeremy

dave-b · Unread post by **dave-b** » 29 Jul 2003, 15:46

Thanks jeremy i had a horrible feeling it may be electrical it only started after travelling 600 miles on the motorway over 2 days. The car seems to be fine at motorway speed though. Quite often I have noticed the problem after cornering hard it always happens on one particular stretch of road after a long left hander, the car just appears to die on me if i slow and stop it ticks over as if its on 2-3 cylinders and wont rev cleanly misfiring and an occasioal backfire. Any idea what I should check first and where?
Thanks Dave

jeremy · Unread post by **jeremy** » 29 Jul 2003, 19:29

Dave
if you had a carburrettor I'd still say fuel - the petrol could be low in the carburrettor and spun to the outside during cornering - starving the engine.
but you haven't so what next? When you go round a left hand corner the tendancy is for the engine and other bits to move to the right, stretching leads from the engine to the bodywork - so perhaps there is a starting point - look at everything that could move.
I'd suggest starting the engine and having a good poke around and a tug on all such leads including the earth leads and the battery connections. Its also worth having a tug at the high tension leads perticularily if they are not fastened down well or are old, but BE CAREFUL with these and use an insulating stick or something as the voltage is huge and a definite health risk.
If you have a distributor cap - well worth a look inside and also worth checking the HT leads - if you have a meter test them and any resistance over about 15 - 20 K ohms should make you suspicious.
Also worth finding the fuel pump and giving its leads a good tug while the engine is running.
If this doesn't work it becomes more interesting!
jeremy

Thregwort · Unread post by **Thregwort** » 29 Jul 2003, 22:26

Diagnostic techniques as commended by Sherlock Holmes involve first eliminating the *possible* causes.
Fuel filter? £7 in Halfords. Replacement? Simple - depressurise fuel system, remove 2 clips, replace filter, fit two new clips.
Result? Clean fuel/no fuel starvation/no rough running when tank nearly empty - BUT, from your point of view, a definite yes/no answer to your question, with positive benefits to your car's running.
Thregwort, Essex UK.

dave-b · Unread post by **dave-b** » 30 Jul 2003, 01:12

Well had a quick look after work and the fuel pipe on the right hand of the fuel rail was leaking so but new clip on it. Also both battery connectors were cracked in half (they both lifted off the battery with a pull) so replaced them to took it for a little spin around the industrial estate seems better but need to re-tax and take it for a good run will pick up fuel filter tomorrow as well. Checked for loose wires couldnt see anything obvious.. perhaps the other faults are the cause.
Dave

Thregwort · Unread post by **Thregwort** » 30 Jul 2003, 23:07

Dave-b,
Sounds like you're on the right track.
Post back when you've put the filter on...
Good luck.
Thregwort, Essex UK.

dave-b · Unread post by **dave-b** » 30 Jul 2003, 23:36

Ok I changed the fuel filter this evening seem to tick over better runs a little better too old filter looked dead old. When I emptied it out the fuel coming out was pretty dirty plus what looked like rusty thick water too.
Dave

Thregwort · Unread post by **Thregwort** » 31 Jul 2003, 15:50

Yech!!
So all your fuel was travelling through that gunk on its way to the injectors - plus the filter was completely useless for any filtering. No wonder you had problems with rough and unpredictable running.
Now do this: go to filling station and fill up - [an oldish car will have water/rust/gunge at the bottom of the fuel tank, which only gets into the fuel when it runs low - so ALWAYS keep a 10 litre minimum in the tank] - then add a good portion of Redex or STP Fuel system cleaning fluid to the tank and leave the car on tickover for 20 minutes or so until it's nice and hot.
Then hit a good section of clear road and open her up in 3rd or 4th gear to get some good high steady revs (don't go into 5th).
Chances are, when you come back you will have a good result with a smooth running motor.
Good luck,
Thregwort, Essex UK.

dave-b · Unread post by **dave-b** » 01 Aug 2003, 20:37

Well got it taxed today so took it out for a blast wow never run so well though some of that must be down to new leads and plugs etc, but the car feels so different now smoother better tick over pulls harder too.... Now all I got to do is hope its not a intermittent problem that will come bcak to haunt me.
I would just like to thank everyone who posted here for their help
THANK YOU
Dave

dave-b · Unread post by **dave-b** » 09 Aug 2003, 15:18

Just a quick heads up took the car away this week and done 1000 miles in 4 days never missed a beat so its fixed.
Just want to thank everyone again cheers..
Dave
ZX Volcane (Wirral)