FAILED on emissions, on every section! *update, PASSED Mot*

[Ryan.g]

The O2 feedback is not on for a reason guys. With the lift and the way Jims cams are set so wild at 6 degrees advanced on the Intake and 6 degrees retarded on the exhaust, running anything leaner than 0.9 lambda and it misfires due to how long the combustion is with the way the cams are timed in and the fuel being burnt to quickly.. Hence more fuel is needed to keep it stable.

When we have set the cams up sensibly on the dyno Jim this wont be an issue.

Ryan

[Ryan.g]

Dam annoying, cause surely all these 1000hp supras and skylines still need to pass emissions and they'll have more mental fueling then me.

They dont pass emmisions they just know a Mot tester which looks the other way. Most high power cars without cats can be made to pass through a certain sequence through mapping but its not a 2 minute job.

Ryan

[Kongaroo]

The O2 feedback is not on for a reason guys. With the lift and the way Jims cams are set so wild at 6 degrees advanced on the Intake and 6 degrees retarded on the exhaust, running anything leaner than 0.9 lambda and it misfires due to how long the combustion is with the way the cams are timed in and the fuel being burnt to quickly.. Hence more fuel is needed to keep it stable.

When we have set the cams up sensibly on the dyno Jim this wont be an issue.

Ryan

So does Jim have HKS 264's like in his profile or something more aggressive?

I have GSC 268 cams which are fairly comparable to the HKS 264 high lift cams (although the GSC's have slightly more lift).

I currently have 3 degrees advance on my intake cam and exhaust is retarded 6 degrees as I read a recent test by ATS Racing that showed good results with this - so not too far from Jim's cam settings. The car idles smoothly with pretty much no lope at this setting. I have previously tried 'straight up' and also 4 degrees advanced intake and 4 degrees retarded exhaust - both also without problems with misfire.

I take it Jim's spark plugs, distributor cap and leads are all in good working order? If Jim's problems are typical of what to expect at 6 degrees advanced intake and 6 degrees retarded exhaust then I'll take that combination off the 'to try' list, lol.

In answer to JMR's query earlier - yes PFC can read voltages from the stock sensors including the O2 sensor. When O2 feedback is active you will usually see this voltage going up and down constantly between 0 and 1. When O2 feedback is off and assuming you have a stable idle/AFR in just one cell then the voltage reading will usually remain constant.

Btw Jim here's a good webpage regarding passing emissions in California - there's a number of things you can check on there if you are wanting to make some last minute checks before your MOT:

http://mr2.com/TEXT/SmogCheck.html

There's an interesting bit about using denatured alcohol in there - apparently this works well with cars that are failing due to being overly rich. All I can say is I'm glad I have a pre-1995 car

[jimGTS]

Ryan mapped before I discovered what cams I had. Was believed 272s due to the sound the car made, but upon lifting the cover I discovered hks 264s.
And the reason for such an agressive setup was the fact that I also discovered hks cam gears. 6 degree advance on intake, 6 retard on exhaust.

It's obviously this setup that Ryan has had to cater for.

[Ryan.g]

The O2 feedback is not on for a reason guys. With the lift and the way Jims cams are set so wild at 6 degrees advanced on the Intake and 6 degrees retarded on the exhaust, running anything leaner than 0.9 lambda and it misfires due to how long the combustion is with the way the cams are timed in and the fuel being burnt to quickly.. Hence more fuel is needed to keep it stable.

When we have set the cams up sensibly on the dyno Jim this wont be an issue.

Ryan

So does Jim have HKS 264's like in his profile or something more aggressive?

I have GSC 268 cams which are fairly comparable to the HKS 264 high lift cams (although the GSC's have slightly more lift).

I currently have 3 degrees advance on my intake cam and exhaust is retarded 6 degrees as I read a recent test by ATS Racing that showed good results with this - so not too far from Jim's cam settings. The car idles smoothly with pretty much no lope at this setting. I have previously tried 'straight up' and also 4 degrees advanced intake and 4 degrees retarded exhaust - both also without problems with misfire.

I take it Jim's spark plugs, distributor cap and leads are all in good working order? If Jim's problems are typical of what to expect at 6 degrees advanced intake and 6 degrees retarded exhaust then I'll take that combination off the 'to try' list, lol.

In answer to JMR's query earlier - yes PFC can read voltages from the stock sensors including the O2 sensor. When O2 feedback is active you will usually see this voltage going up and down constantly between 0 and 1. When O2 feedback is off and assuming you have a stable idle/AFR in just one cell then the voltage reading will usually remain constant.

Btw Jim here's a good webpage regarding passing emissions in California - there's a number of things you can check on there if you are wanting to make some last minute checks before your MOT:

http://mr2.com/TEXT/SmogCheck.html

There's an interesting bit about using denatured alcohol in there - apparently this works well with cars that are failing due to being overly rich. All I can say is I'm glad I have a pre-1995 car

Changing the timing of the intake cam is the one which normally causes lumpy idle. If they were set at the HKS recommend settings then this problem wouldn't be present. Best settings i have found before on the dyno for the Hks 264 units on a rev3 is around +2 on Intake and -2 on Exhaust.

Most engines with cams under 272 should idle at stoich with the cam timing at a sensiable setting.

When asked to map this car around a year and half ago it was just imported and i was asked to put a map on the car at a low boost level so it could be sold. Now Jim owns the car i have been telling him to bring the car to the dyno so it can be setup fully ie cam timing etc

When the car came over it idled at 1700rpm just because it miss fired below that where it was around stoich. Richening the mixture helps with this and i managed to get it near 1000rpm to make the car more usable.

but who knows whats done to this car. It could have stronger valve springs, oversized valves etc.

I got Salmanzers car to idle better with 1800cc injectors, 280 cams, t88 etc

[jimGTS]

Cars only been here a year, hense it's mot this week. LOL
It's always idled at 1400-1500 since I've had it.
Be nice if it did idle at 1000. Just need some dyno time. Or another road map from Ryan just to get me through this mot.

The cam setup is a rough guess, as it's got modified stock cam gears. Hks gear bolted on somehow, so from the angle I've been able to view it is ni on 6 and 6. But could be -/+ 1 degree I guess.

[ryan]

Have you, contacted the seller,after all the car needed an MOT when it entered the country? How did they get i thru? Or you changed specs since?

[jimGTS]

friendly mot man last time around it seems before i got the car, lol

[ryan]

friendly mot man last time around it seems before i got the car, lol

LOL I suggest you pay 'friendly MOT man' a visit and give him a bung

[jimGTS]

friendly mot man last time around it seems before i got the car, lol

LOL I suggest you pay 'friendly MOT man' a visit and give him a bung

Well it was done like 6hours away where it was imported. Not werth me taking a 12hour round trip just for an mot! LOL

[Nails]

I can't believe people dont know any friendly MOT places, first step you are doing wrong is going to big places, named places etc, go to back street side street ones. The emissions test is a joke any way.

[Dale_V]

agreed ^^

waving a £20 note infront of their nose usually helps too

[jimGTS]

the fact these guys opened the bonnet to try and find the dipstick means i dont trust any local garages round here to do any work, so i dont have any "friendly" garages. just friendly mr2 tuners and affliates, lol...

[JJ]

Jim... sort the cam timing out to HKS specs..( they've done the engineering behind it all ! ) I've found setting them up to recommended timing specs to be the best for all round performance / running. Previously, i'd mess with them to pull the turbo in quicker... make it run harder at the top end... but this would leave a crap idle.. lumpy / rich ( to keep it running )... its simply not worth it .. Screw the PP setup...the cams may have only just been chucked in to get rid of it.... The setup is only as good as the guy setting it up ( mechanically ) .. For all you know.. you maybe losing some power out of that set up !!

The key is to getting running like stock - smooth and fast !!

Again.. just a comment of setting up quite a few variations of cams... if the cams are originally JDM purchased ones for its year ( not stateside Rev 1/2's fitted to rev 3+'s ).. they should fit into you rev 3+ engines with the cam gears zero'd out.

If the HKS cams that were originally destined for the Rev 1/2's have been fitted ( like most importing from the stateside ) the cam are still excellent and still will work, but the cam gears will need some adjustment to bring them into HKS specs...

Rule of thumb...ensure the mechanics of the engine is correctly setup prior to any sort of mapping.

[Nails]

the fact these guys opened the bonnet to try and find the dipstick means i dont trust any local garages round here to do any work, so i dont have any "friendly" garages. just friendly mr2 tuners and affliates, lol...

youre not getting them to do any work though, just doing a MOT?

[jimGTS]

surely you cant build up a friendly relationship with a place if you only go there once a year for an mot...


if i knew someone who worked at one of these places, then of course that is different and you maybe could "get away" with more.



thanks JJ for that, i wanted to get all sorted and mapped up with ryan playing with the cams earlier this year, but had to wait to sort my manifold out and install my WI. just taken more time than i realised. and now mot has come around quicker than i hoped.

[JMR_AW11]

surely you cant build up a friendly relationship with a place if you only go there once a year for an mot...


if i knew someone who worked at one of these places, then of course that is different and you maybe could "get away" with more.

My advice would be to go somewhere where the test station manager/owner is into motorsport or similar.

The place I go to for MOTs are pretty good. They don't let me cheat but they do try their best to help the car pass the test because they all have similar cars and they understand the problems etc.

The place I go to is firm but fair. They never 'cheat' so the car has to pass the test but they let me tweak and play with the car and I book in at a quiet time so they don't need to rush me to pass the test.

[Nails]

surely you cant build up a friendly relationship with a place if you only go there once a year for an mot...

depends how friendly you are lol

[jimGTS]

Thank god!!

Am well pleased, got through the MOT today without a hitch!

Couple of advisories, but just scrapped through the emissions.


Only thing I changed was new oil and filter, new vpower, and this special prolong mpg emissions liquid stuff. Think it's this stuff that seriously helped!!!


Big thanks to owen at Kent cat craft for sorting me out!

[stevenb]

Hi Jim,

I'm wanting to test my N/A on emissions to see how it does before I MOT it as I have a rev 2 but de-catted.

Anyhoo....how much did they charge you and were they ok doing just an emissions check?

Cheers

Steve