New here and in need of some help!!

[rabbit1]

Hi there, I hope I can get some help on here as this is now driving me crazy!!

1997 1.6 Vauxhall Astra 1.6 vArtic 8 V

My lad who has just passed his test has inherited this car from my ex and I am desperately trying to sort out the emissions for the MOT, here is the story so far.

The car had a bad misfire and was heavy on fuel, the bloke who owned her before said he had her on diagnostic kit and replaced the Lamba sensor and the e.c.g valve, this did not cure the fault 100% and he was advised that the air intake valve needed replacing as the engine was running at -32 degrees and burning fuel. (just found this out) Been told there is no such part!!

WE put her through the first MOT and she failed on a few basic bits, but the emissions were very high, H.C and Co2.

Second MOT : all the basic bits done and brand new plugs and HT leads, she still failed on emissions.

Third MOT, was advised that the cat needed replacing to address the emissions problem, replaced the CAT and she still failed on emissions, CO2 was high, H.C was higher still.

I have a mate who is a mechanic and has helped me so far, but we are both stumped and don't want to spend too much on a 1997 car.

I have been informed by Vauxhall over the phone, that it could be the engine management sensor (temperature 2 switch).

Searching other information, I was leaning towards the MAT sensor, manifold air temperature valve?

My lad is now getting stressed lol, as he passed his test 3 weeks ago and wants to drive, so any help would be gratefully appreciated...

Forgot to add, after the new leads, plugs and CAT, she has no misfire and runs well, it is just the emissions for the MOT that's the problem....

 

[djwilde69]

welcome check the timeing as if it's even 1 tooth out the emission's will rocket!!
and you will burn to much fuel

 

[rabbit1]

Thanks will do, although would that affect the temperature of the engine, she was registering - 32 degrees when put on diagnostics? That seems to be why she is burning more fuel and high emissions....or so i have been told!!

 

[djwilde69]

if the engine think's it's cold all the time there one of them E-BAY chip's in so it over fules all the time even if the engine is red-hot also look in the ECU for any thing diffrent.

 

[rabbit1]

thanks...what's the best way of testing the ECU, diagnostics hook up?

 

[farmerboy]

Coolant temp sensor maybe?

 

[rocawearman]

i know its a little off what your problems are but i recently had my car fail a mot on emissions (have a straight through exhaust and standard cat) it was miles over so after a few days of checking her over we decided to fabricate a type approved cat onto the car and it worked a treat she even got 0.001 or something on emissions and now she runs better than ever...

was an expensive do though but i think its well worth it

 

[rabbit1]

Thanks

 

[sammy_lou]

Temperature sender, as said by DJ, due to it reading 32 degrees - it's always on cold start and chucking too much fuel through. Does the temperature gauge read properly, as in creeping up slowly, or shoot up and stay in one place?

 

[Rusty]

CTS would be my first port of call, given the ECU is showing -32°

 

[rabbit1]

Cts ??

 

[fleck]

coolant temp sensor.

 

[rabbit1]

Thanks ...appreciated

 

[Mr Skint]

cts for sure mate, not sure where it is on that engine but may be on or near the thermostat housing

 

[carter]

you saying about intake valve, sure its not an inlet valve as that could make a difference, however your car wouldnt be running as well as it is. wish i could help

 

[rabbit1]

Well I just took her for a spin to check the temperature gauge, she was slow to get a reading on temperature and after 3 miles of town driving got about half way 90 degrees and stayed there! Ticks over and runs fine?

 

[Mr Skint]

yeah but there is two coolant sensors on your engine, one for the ecu and one for the dash gauge. Maybe someone who knows it location will tell you where it is as im not that familiar with the engine

 

[rabbit1]

Thanks..

 

[rabbit1]

Just done a bit of research on the web and it is saying that with a faulty CTS the idle would be rough with blue smoke, My car is fine on idle with no blue smoke. I just suggested the CTS to my Mechanic mate and he thought this was unlikely?

 

[Mr Skint]

well thats the sensor that tells the engine what temperature its running at so it can adjust to air/fuel ratio and your engine is being told its -32 then id be inclined to change it, plus being such a cheap part its worth changing it to eliminate it from possible causes