[astra1976]

Hello all.
newbie to the site but not a newbie to vauxhalls.

I have a problem where the car is not running well.
the car starts first time everytime but when you start it from cold or hot it revs really high for about 5 seconds and then drops down and idles fine.
when travelling at low or high speeds the engine seems to lose power/hessitate then return to normal. this is only for a second but very noticable and is rough under acceleration.
I have no engine light coming on and no fault codes.

only had the car a month and have done allot to it in that time.
cam belt/water pump/thermostat/alternator belt.
new egr valve and idle stepper motor.
full service using gen vx oil and filter etc
bosch super 4 plugs
gen vx lambda sensor

it is a 1.6 8v x16szr

have read quite a few threads but still not sure what it could be.
could it be a problem with the cat. or does this engine have a maf or map sensor? if so where are they?

is there anything anybody can suggest? I am having to do allot of mileage at the moment and it is not very fun to drive.

thank you all in advance.

 

[mr loopey]

did you set up plug gaps correctly and have good lead connections

 

[astra1976]

hello.
they are bosch super 4's and the gaps were perfect. the leads seem ok

 

[astra1976]

so been reading a few more threads on here.
symptoms sound like map sensor or knock sensor. is there anyway to check either of these?

 

[astra1976]

anybody?

 

[Boroboy]

I presume it's the spi engine not mpi? If so, it's normal for the engine to rev high for a couple of seconds & then tickover at a normal speed. Mine dose & I own the 1.6 8v spi model.
You could try changing the coil pack, easy diy change. You need to take battery off to do so, makes life easier. Torx heads, I believe. You can buy a second hand coil pack from your local breaker for around £25. They're around £150 from Vauxhall. Have you changed the plug leads? If you buy a copy set, make sure they fit onto the coil pack properly. If not, you could try & get hold of a second-hand set. Think again Vauxhall charge around £80 for 4 leads.

 

[Boroboy]

Since having your thermo replaced, does your car get up to normal running temp (half way on gauge), within 2/3 miles of driving? If so, then your thermo is OK.

 

[Brooksey]

have you cleaned the throttle body? may help smooth things out for you.

mine always starts with higher revs from cold, around 1500-1700 then settles to somewhere around 800 once warm after a few minutes or so.

 

[leeno392]

Id try the map sensor mate, should be clipped by your windscreen, should get 1 from the scrappy for a fiver...

 

[astra1976]

Hello all.
yes the temp goes to halfway as it should after 3-5 miles and the throttlebody is spotless.
going to try to get a coil pack tomorrow and a map sensor.
is there anyway to test these things?

 

[Boroboy]

Hello all.
yes the temp goes to halfway as it should after 3-5 miles and the throttlebody is spotless.
going to try to get a coil pack tomorrow and a map sensor.
is there anyway to test these things?

Coil pack is difficult to test, as I had a faulty one & I was still getting a spark to the plugs. Once you've changed it you should know straight away if that's been your prob. It's also possible it could be your leads too. If your buying a coil pack, see if the breakers with through in a set of leads for free.
If so, change leads first, run car see how it goes. If no better change the coil pack.
Let us know how you get on with it.

 

[astra1976]

cheers. will update later

 

[tavimage]

did you set up plug gaps correctly and have good lead connections

you should never adjust the gaps on twin electrodes or bosch super 4's, the gap is set perfect at the manufacturers, and any tweaking can cause major problems, as long as you asked for the right set, they will be set up perfectly

 

[astra1976]

I have purchased a genuine new set of vx ht leads but have not been able to get a second coil of map sensor.
does anybody have one they no longer need? I have a brand new egr valve and gasket I would be willing to swap.

 

[astra1976]

that should of said second hand coil pack and map sensor.

also forgot to mention that the new leads have not solved the problem.

 

[chrisshu]

Hi, have you checked the fuel pressure regulator? it's part of the throttle body. Chris

 

[Brooksey]

also have you cleaned the breather pipes, I did at the weekend for the first time and was amazed at the gunk stuck in the pipes. I don't know if it will answer your issue but it can't hurt either seeing as you are fixing things in the engine bay anyway.

 

[astra1976]

Hello.
Where on the tb is the regulator? and can it be cleaned out or does it need replacing?
have checked all the breather pipes and they where all clean.
thats one of the things I dont understand. the engine is spotless. tb looks like new and all the breather pipes are clean and with all the new parts I have added it should be running perfectly but it is not

 

[chrisshu]

Hi, the x16szr has the pressure reg. on the side of the tb held with 4 screws. Check diaphragm has no splits or holes. Only serviced as complete throttle body. Chrisshu

 

[astra1976]

when you say only serviced as complete throttle body do you mean that if the reg is no good I will have to replace the whole tb?