Mot Failure :(

[viper4460]

hi there this is my first post, and i need some help. i have just brought a 91 nissan pulsar GTI-R and its just been taken for its mot and failed. the car passed on everything apart from emmisions. basically the co was to much or summit like that, he said its buring the flue ok but its running well to rich well it should be about 3.50% and i was running nearly 9 lol. i have checked and i have a standard ecu its a fresh import and its my secind pulsar but this is the strange bit. last time i had my pulsar it rev limited just into the red, and as i just tootle about the bloke at mot said maybe as u just drive slow it needs opening up, so i did i took it for a bit of a thrash and it revs off the clock? so i took it back and it was no better, so what i need to know is does anyone know why it might be overfueling so badly even thou it has a standard ecu and why does it rev so high cuz i dont think its safe cheers chris![/b]

 

[AJ4]

Does the speedo read in MPH or KPH ? If it reads in MPH then its probably delimited ( its usually part of the process from converting it ).

Don't know why its overfueling though, do a fault code and see if your AFM is ok.

 

[viper4460]

it reads in kmh but its the rev counter is going off the clock its reving to over 9 grand how would i test for overfueling like ur saying as i dont really understand

 

[nismoboy]

could be a faulty lambada sensor :?:

 

[viper4460]

ohh rite so a faulty lambda sensor would cause the immisions to be so high. do the pulsars have a egr valve? (Exhaust gass recurculation valve)

 

[AJ4]

no ( thankfully ) they dont

Sounds like its been de-limited anyway, if your really bothered it might be worth whipping the dash out and looking for suspiciously wired in little black boxes

 

[viper4460]

ok m8 will do but u recon the high emmisions could be the lamda sensor. how would i go about finding fault codes gfor the exhaust gas probe or summit

 

[AJ4]

Have a look at the FAQ's How to guides on finding fault codes, before someone threatens to rip your head off ( very very long story )

http://bb.gtiroc.com/viewtopic.php?t=10984

 

[Fast Guy]

What exhaust do you have on? Refitting the cat (if it's not on) may help.
Does the car drive OK? Or does iit hesitate or give out clouds of black smoke etc?

 

[Shaun]

Think were all missing the point abit , it shouldnt fail on emissions as a 91 import is exempt

 

[antgtir]

Think were all missing the point abit , it shouldnt fail on emissions as a 91 import is exempt

Correct, but if its running rich then maybe there is some other underlying prob's that need to be ironed out??

What engine work do you know about has this car had?? I suppose if its had extensive engine and gearbox work then it would be possible to rev at such high levels, however i wouldn't advise doing this again until you know whats going on.

TBH mate i wouldn't rev it much past 6k anyway as if you look at alot of the power curves from the R (standard) it seems to reach its peak power at this point so going beyond this wouldn't bring any benefit and only bring you closer to the R breaking

As Fastguy said, has the cat been removed?? Lamda sensor would if knackered would cause the engine to over compensate with its fuel and air mixture causing it to overfuel. Have a good scout around and see if there are any other obvious probs before you start buying parts that you may not need in the end.

Goodluck, Ant.

 

[viper4460]

thanks for all the replies i really appreciate it. it stil has its cat on so that irons that out, it could be the lamda sensor i will look into this but i know 91 doesnt come into emmisions but being as high as it is its a failure as its way way to rich

 

[jonee]

r

men i'm sorry but a 1991 vintage vehicle should comply with the exhaust gas readings of


co 3.50 % max

hc 1200ppm max

jonee

 

[Shaun]

Re: r

men i'm sorry but a 1991 vintage vehicle should comply with the exhaust gas readings of


co 3.50 % max

hc 1200ppm max

jonee

Yes mate,you are right,but iirc it's because its an import and Pulsar has no listing on the emission data base so no figures are available and is there fore exempt My emissions have never been tested

 

[petegtir]

Re: r

men i'm sorry but a 1991 vintage vehicle should comply with the exhaust gas readings of


co 3.50 % max

hc 1200ppm max

jonee

Yes mate,you are right,but iirc it's because its an import and Pulsar has no listing on the emission data base so no figures are available and is there fore exempt My emissions have never been tested

they will use the uk sunny gtir as the listing for it. you can get away with it in like an MR2 turbo as they never sold them here

 

[campbellju]

My car failed recently on emissions. We guessed Lambda sensor and thankfully we guessed right. £120 for a new one it cost me though

Not saying this is your problem but food for thought.

Jim

 

[jasegould]

Yes mate,you are right,but iirc it's because its an import and Pulsar has no listing on the emission data base so no figures are available and is there fore exempt My emissions have never been tested

No, if a car is not listed they use the default which is 3.5%. Altho, as MoT test stations are self governed (albeit the odd visit from VOSA) different places have different ways of doing things, hence yours have not been tested.

Could be the lambda, but if your mechanic has the emissions data he should be able to tell you if it is, failing that the coolant temp sensor and dodgy MAF sensor can cause high emissions.

Jay

Jay

 

[Fast Guy]

Re: r

men i'm sorry but a 1991 vintage vehicle should comply with the exhaust gas readings of


co 3.50 % max

hc 1200ppm max

jonee

Yes mate,you are right,but iirc it's because its an import and Pulsar has no listing on the emission data base so no figures are available and is there fore exempt My emissions have never been tested

I've always been tested. (92Jreg) but it's only subject to the basic test above and flies threw even with a decat mongoose fitted.
IIRC Hannie failed with about 7% and she just fitted a cat and it passed. Maybe she can confirm that.

 

[jonee]

r

if the mot tester has to apply a default limit then the limit for a 1991 car with or without a cat is as below.

co 3.50%

hc 1200ppm

no exceptions

jonee

 

[sypher]

Campellju, at that price i assume you bought a genuine nissan item specifically for the GTiR, if so can you tell me what the integrator output voltage varies between? as you know there is a various opions on this, i would like to know what is max' voltage, 09 V, or 1.5 V (as stated in nissan workshop manual) ??

If car runs fine i would suggest checking of lambda probe voltage to begin with..