Omega 2.5 v6 poor acceleration

[niki85]

Hi

i have opel omega 2.5 v6 petrol year1999., automatic gearbox, with very poor acceleration ( like car with 55hp ), no DTC in engine, no dtc in gearbox, all parameters are good (with opcom),
engine compression on all 6cyl are 10-11bar (very good), catalytic convertors removed, car have LPG, on lpg same poor acceleration like on petrol, on neutral, idle is perfect, revs ok, when start to drive work perfect but no power.

i`ll try all i know, what next ??

thanks for help

regards

[radb02]

Even if the v6 was misfiring on one cylinder its sometimes hard to tell on idle and sometimes doesnt bring up a fault code. I would suggest unpugging one ht lead at a time and seeing if its worse or the same with each lead unplugged.

[niki85]

i`ll try that too, it`s ok, when i unplug one cable engine start to shake a little, on all 6 same... it`s not that

[niki85]

i thinks it something with automatix gearbox, but it work like a new, all parameters in gearbox is ok, no fault codes, like on engine. it`s a mistery

[Meat-Head]

1) Omega :puke:

2) STUPID question, is it making gearbox noises?

3) Omega :puke:

4) Is it possable the brakes have stuck on?

5) Omega :puke:

6) Is it possable The candles have been eate away by the gas?

7) Omega :puke:

8) Fuel filter?

9) Omega :puke:

10) Same autobox as Izusu Trooper

11) Omega :puke:

12) Airflow meter

[niki85]

all filters are new, all spark plugs are new, gearbox don`t make any noise, airflow on parameters goes from 8-160kg/h,
it can be only Omega :)

[oldford]

Airflow indicates roughly 40kw (55 bhp) maximum power.
Does the throttle open fully?
What are the signals from the Oxygen sensors when the airflow is 160kg/h and what's the rpm at that moment?

[niki85]

i found something, now i go to try fix that
secundary air pump don`t work, i don`t know is that reason
for poor acceleration but i`ll try to fix and try....

[Meat-Head]

Won't argue thought second air pump was purly when old for emmisions.

OFF TOPIC:-

Corvette C4 - HAS to HAVE an air pump, as you floor it, thres no oxygen in inlet manifold, motor provides air for couple of seconds.

What speed can you get if you GENTLY speed up

[del635]

?Cat blocked or partailly blocked?

[oldford]

Corvette C4 - HAS to HAVE an air pump, as you floor it, thres no oxygen in inlet manifold, motor provides air for couple of seconds.

Without oxygen in the inlet manifold, the engine will die as it can't burn fuel anymore.
Can you elaborate what you mean here?

[niki85]

i fix secondary air pump, now it`s work when engine is cold, but car still slow accelerate.
Cat is removed, i try to remove complete exahaust, still no acceleration but having trouble with neighbor :)

every f***ing sensor and valve i`ve checked all ok,
i try to lift a car put in D (drive) and manualy turn rear wheels goes easy....

what a car...

[Meat-Head]

OFF TOPIC:-



Can you elaborate what you mean here?

Sure, your one of them cool members that rarely asks for anything.

Rumor has it that the throttle butterfly opens and the air/oxygen is sucked into the engine.

Like you say, no oxygen, no go. So they have a blower motor *THINK* on the drivers side (LHD), when when full throttle is asked for works this motor which 'inflates' the intake manifold with air.

Only heard this the one, guy was a Spig, works in the courts, can't remeber what was infront of him for :roflmao:

ON TOPIC:-


i fix secondary air pump, now it`s work when engine is cold, but car still slow accelerate.
Cat is removed,

every f***ing sensor and valve i`ve checked all ok,

what a car...

JUST A COTTON, PICKING CHEESE GRATING MINUETE.

Don't think it's your problem as V6 - had one where under the throttle body 4 cyclinder where there is a small brass pipe was blocked solid.

NOT SURE on this one, look at This - The Range Rover's have trumpets in the manifold for length, would GUESS Omega :puke:would have some thing simular

http://www.britishv8.org/articles/Images-V15-1/Towery-EFI-2.jpg


What are the emmision readings?

Have you tried disconnecting the battery?

OFF TOPIC:-

Had a Clio the coil pack was internal short, firing two cyclinders at once.

Can you make a DK Tube video Digital Kaos - KaosTube Videos (http://www.digital-kaos.co.uk/forums/KaosTube) of various engine noises?

[niki85]

i try new maf but same result, maf on full throttle on kick down in second gear goes max to 3.5v...

[oldford]

3.5 volt for the MAF sounds a bit low.
What was the airflow in kg/h?
What were the signals from the Oxygen sensors at that moment?

N.B.: You should read out airflow at full throttle at the rpm where the maximum power is delivered - 6000 rpm. You need a minimum of 490 kg/h.

[niki85]

i don`t have that much maybe until 300kg/h, but it`s very hard to get 6000rpm (when drive) 0-60mph about 30 seconds... lambda is about 0,4v-0,5v in that moment (first and second lambda is same because i take out cat),
now i think that problem is in engine (maybe some inlet valveS get stuck, or hydraulic lifterS)

[dannyuk89]

unplug air flow sensor see if it improves if it does id go for one of them

[oldford]

A 1999 model would have the X25XE engine.
It does have 2 Oxygen sensors, but both in FRONT of the cat's. One on each side of the engine. There should be no Oxygen sensors behind the cat, otherwise it's not a 1999 model.

A 0.4 to 0.5 volt signal from the Oxygen sensor is not rich, like you would expect on WOT. It's around lambda 1, but not switching? Do the heaters of the Oxygen sensors work? Do they switch at idle?
Can you find the fuel trim in the live data (maybe it's called Block Learn)?

N.B.: You can't lock the gearbox in say 2nd gear?

[niki85]

i return car to customer, i try to disconnect maf, 2 knock sensors, 2 oxygen, car accelerate same, only difference is work on idle, then i try remap ecu, give more fuel and spark advance, and nothing ( maybe little better acc. ), on second gear with kick down after 2miles of drive i get 6000rpm but can`t reach 6200rpm to switch 3rd gear and maf goes to 415kg/h...
99% engine is faulty.

Thanks to all for help

[Meat-Head]

comssion tested?