1.8 cav 1995 multec engine problems

Hi there, I own a cav 95 for the last 3 years I have had jerking
problem the same as I have read on this site but slightly different as
in no engine light, no fault codes. When it first started it was hardly
noticeble, 3 years later the cars undrivable. Over the years it has had
dizzy cap, new plugs, fuel filter, injector cleaner, different
injector, (£10 ebay) just recently, mobile tuning EXPERT 2 years ago,
(messed with stepper motor nearly blew engine up)
£40 lighter no cure, cleaned all the earth connections I can find,
took it to a small garage/unit
11/7/06 put magic box on AGAIN could not find anything out of place (
nice lad) did not charge me after 1 1/2 hours fault finding. One of his
lads (after work vauxhall nut) says it could be Manifold Absolute
Pressure Sensor, (where is that) £51 0ff the net. Lad I know is
pointing me towards Crank Sensor, (know where that is and looks a pig
to do) £40 + off net.
Noticed the display on magic box said fuel... LEAN, jerks from O to 50
mph light throttle usage, obviously above 50mph + the jerking appears
less because engine running faster.
Dizzy cap was first thing to change nearly 3 years ago didnt make any
difference.
Any help would be appreciated. Steve.

 

Hi there, I own a cav 95 for the last 3 years I have had jerking
problem the same as I have read on this site but slightly different as
in no engine light, no fault codes. When it first started it was hardly
noticeble, 3 years later the cars undrivable. Over the years it has had
dizzy cap, new plugs, fuel filter, injector cleaner, different
injector, (£10 ebay) just recently, mobile tuning EXPERT 2 years ago,
(messed with stepper motor nearly blew engine up)
£40 lighter no cure, cleaned all the earth connections I can find,
took it to a small garage/unit
11/7/06 put magic box on AGAIN could not find anything out of place (
nice lad) did not charge me after 1 1/2 hours fault finding. One of his
lads (after work vauxhall nut) says it could be Manifold Absolute
Pressure Sensor, (where is that) £51 0ff the net. Lad I know is
pointing me towards Crank Sensor, (know where that is and looks a pig
to do) £40 + off net.
Noticed the display on magic box said fuel... LEAN, jerks from O to 50
mph light throttle usage, obviously above 50mph + the jerking appears
less because engine running faster.
Dizzy cap was first thing to change nearly 3 years ago didnt make any
difference.
Any help would be appreciated. Steve.


air getting into the fuelline??

 

A while back my Omega would try and rattle itself to bits at any revs
below 2000 or above 2500 when under load, no EML; at least vaguely
similar to your symptoms. Turned out to be HT leads. 25 quid from local
motor factors.

 

Hi bongo, you are not the first to mention air getting into fuel line.
cant get my head round it though, If the fuel is under pressure and air
is getting in then surely fuel should be coming out where the air is
going in. (no)? First time on here so dont know where this reply will
go.

 

Hi bongo, you are not the first to mention air getting into fuel line.
cant get my head round it though, If the fuel is under pressure and air
is getting in then surely fuel should be coming out where the air is
going in. (no)? First time on here so dont know where this reply will
go.

 

Thanks for your reply to my problem, you just reminded me the ht leads
was the second thing I replaced 3 years ago then the plugs. Had Montego
with same problem changed dizzy cap no more problem.

 

spark plugs, leads, coilpack or coils, oxygen sensor [if fitted]

mike

Hi there, I own a cav 95 for the last 3 years I have had jerking
problem the same as I have read on this site but slightly different as
in no engine light, no fault codes. When it first started it was hardly
noticeble, 3 years later the cars undrivable. Over the years it has had
dizzy cap, new plugs, fuel filter, injector cleaner, different
injector, (£10 ebay) just recently, mobile tuning EXPERT 2 years ago,
(messed with stepper motor nearly blew engine up)
£40 lighter no cure, cleaned all the earth connections I can find,
took it to a small garage/unit
11/7/06 put magic box on AGAIN could not find anything out of place (
nice lad) did not charge me after 1 1/2 hours fault finding. One of his
lads (after work vauxhall nut) says it could be Manifold Absolute
Pressure Sensor, (where is that) £51 0ff the net. Lad I know is
pointing me towards Crank Sensor, (know where that is and looks a pig
to do) £40 + off net.
Noticed the display on magic box said fuel... LEAN, jerks from O to 50
mph light throttle usage, obviously above 50mph + the jerking appears
less because engine running faster.
Dizzy cap was first thing to change nearly 3 years ago didnt make any
difference.
Any help would be appreciated. Steve.

 

Hi mike, plugs & leads made no difference. old cars years ago use to
suffer coil problems but still a possibility. Could go down the oxy
sensor road but would that not show on the magic box thats just been
pluged into the car ?.

 

Has it got an egr valve fitted?
Late Astras give similar symptoms when egr is knackered.

Hi there, I own a cav 95 for the last 3 years I have had jerking
problem the same as I have read on this site but slightly different as
in no engine light, no fault codes. When it first started it was hardly
noticeble, 3 years later the cars undrivable. Over the years it has had
dizzy cap, new plugs, fuel filter, injector cleaner, different
injector, (£10 ebay) just recently, mobile tuning EXPERT 2 years ago,
(messed with stepper motor nearly blew engine up)
£40 lighter no cure, cleaned all the earth connections I can find,
took it to a small garage/unit
11/7/06 put magic box on AGAIN could not find anything out of place (
nice lad) did not charge me after 1 1/2 hours fault finding. One of his
lads (after work vauxhall nut) says it could be Manifold Absolute
Pressure Sensor, (where is that) £51 0ff the net. Lad I know is
pointing me towards Crank Sensor, (know where that is and looks a pig
to do) £40 + off net.
Noticed the display on magic box said fuel... LEAN, jerks from O to 50
mph light throttle usage, obviously above 50mph + the jerking appears
less because engine running faster.
Dizzy cap was first thing to change nearly 3 years ago didnt make any
difference.
Any help would be appreciated. Steve.

 

Hi, yes it has EGR, when I took the car in on the 11th car was picked
up by daughter-in-law so never got speak to anyone. All the replies on
this problem are pointing towards sensors that I dont know if they
would have picked up on when the box was plugged in to the car. I have
been told crank sensor would not show, As for EGR, Haynes show you how
to test it. Best thing would be to to find same spec car in scap yard
and get all the bits suggested by everybody. Many thanks. Steve.

 

Hi bongo, you are not the first to mention air getting into fuel line.
cant get my head round it though, If the fuel is under pressure and air
is getting in then surely fuel should be coming out where the air is
going in. (no)? First time on here so dont know where this reply will
go.


You have a fuel pump. the pump sucks fuel in the inlet and forces it out
under pressure at the outlet. if you have a leak between pump and engine,
fuel under pressure leaks out. If you have a leak between the inlet and the
tank it will suck air in. Try sticking a pinhole in a plastic straw and then
use it to drink a can of coke to see the effect.

Mike

 

Hi Mike, Thanks for the explaination. I changed the fuel filter a
couple of months ago thinking it could be that, I thought i found the
problem when i noticed the filter the wrong way round, alas it wasnt to
be. I checked the rubber hoses to and from the filter and made sure
they were secure after new filter was fitted, the car was just the
same. Steve.