Hi guys,
as I've mentioned in another thread on the cosworth cams, my car has been behaving crappily recently after the install of the cosworth cams. What's bewildering is that I've since put back the STOCK CAMS and the problem is still there! it's frustrating the hell out of me

existing mods:
Trust PE2 exhaust
Blitz SUS pod filter with custom heatshield (using stock MAF pipe/holder)
Nisei UICP, custom-fabricated LICP and O2/downpipe
stock turbo
Perriin MBC holding about 28 psi
AEM methanol injection kit (50/50)
ECUTEK-tuned

I was sitting pretty at approx 350whp and 55kg/m torque
click link:
http://img.photobucket.com/albums/v4...hECUTEKhub.gif
and the car was a pure JOY to drive, and the SST was holding up perfect with no CELs, and buttery-smooth.

THEN all hell broke loose after I got the Cosworths and installed them. Right after installation, the low-end became really jerky (it was absolutely perrrrfffecct, right up till this point) and even after retuning, the jerking never went away. Now I would like to reiterate again that I've seen put back the stock cams, AND the original ecutek tuned map I had just before I put in the cams. NOTHING ELSE WAS CHANGED except the cams. and those too have been replaced with stock since!

exact description of problem:
at low rpms below 2k, the rpm needle would not climb smoothly up to speed, instead it would waver two or three times as I lightly accelerate from 1k to 2k. Instead of smoothly accelerating from stop, it would move off, lurch a few times as speed increased, until it reached approx 2k rpm, before it would be smooth again and drive normally. The car will visibly (and nauseatingly) LURCH a few times every time I accelerate from stop. This happens in all gears if the rpm is low, but most prominent in 1st gear and R gear. Also idle is erratic now and flutters, when the car is stopped. It has occasionally stalled a few times when driving at low speeds (eg. traffic jams, or in carparks) until my tuner temporarily-raised the idle rpm to about 850rpm. This has gotten rid of the stalling, but the jerkiness is still there.

I had initially thought it was simply a matter of retuning that was needed after the cams installation, but my tuner has spent many many (maybe 6-8h!) trying to rectify this for me, to no avail. Now before you question my tuner's ability, he has managed to tune many cars with cams before without issue, and a fellow SST who has the same cams installed at the same workshop, had his car tuned by him, with none of these symptoms I have! Also, as mentioned, I have since installed the stock cams and am using the same ecutek map as before (the one that produced the above attached dyno graph) and the problem is still there!

I've also noticed the problem is not there when the car is still cold. But returns once I've driven a while and the everything's warmed up. <--- what could this mean?

I've since tried a few things:
MAF sensor - have swapped my MAF sensor with another X's - no fix
disconnected meth injection - no fix
swapped pod filter with another - no fix
flushed out and replaced all the SST transmission oil - no fix
swapped spark plugs with new ones - no fix

I've run out of ideas. My tuner has tried adjusting every damn setting he could think of, to no avail. Anybody have any idea? Any SSTs experience this?

Would really appreciate some help here. I've got no CELs and no idea what the hell's going on and it's frustrating the hell out of me! (and my tuner)

Anybody have any suggestions? Anything at all you can think of that might be the problem? This's killing me

 

It sounds like you have the cam timing out of phase but I'm pretty sure you guys already checked that. I know on K series engines if you damage the dowels on the cams or lose even so slightly, it will throw the timing off since it reads timing position on both cams. Check your sensors if they are dirty or damaged. Just some ideas. Good luck.

 

cam timing.. hmm. never really looked into that. I assumed the workshop knows what they're doing when they installed the cams. But from your experience, if the cam timing/sensors was improperly set up, would the symptoms above correlate with this?

thanks for the suggestion though. will try to look into it. good luck.. yeah I'll definitely need that! cheers.

 

damn bro good luck on finding a resolve to this

 

sorry to hear this, good luck on getting this fixed

 

Do you have a wideband O2 installed? Are the AFRs around 14.7 at idle and cruise or is it jumping around? A bad front O2 would cause similar problems.

 

yeah man good luck...makes me kinda not wanna get new cams on mine...hope u get it fixed...

 

Don't have a wideband, but from the ecutek data logging, according to my tuner, the AFRs are all sitting right.

Guys, please don't take this as a negative for the Cosworths, cos as I said, even with the stock cams in, the problem's still there. I believe something went wrong during the installation. Not the cams themselves at fault I think.

 

Are you sure the AFRs are okay in closed loop (cruise and idle)? Open loop I'm sure is fine since it goes off of your fuel maps but your AFRs in closed loop are adjusted with feedback from your front O2 sensor. Did your tuner measure your AFRs in closed loop or only on the dyno at WOT?

 

SiC, yeah, closed loop and open loop both checked.

Any idea how I could check the cam timing or if the cam sensors are working properly by myself? sorry I'm not too technically inclined

 

To check the initial cam timing you pull off your valve cover and turn the crank to top dead center for #1 cylinder. Check the timing marks on your cam sprockets and make sure they are both aligned in the top dead center position.

To check your mivec, you'll need a logger capable of logging mivec degrees such as the Mitsubishi MUT3. I'm not sure but the ECUTek Delta Dash may also support this.

I'm sure you checked but you don't have any intake leaks do you?

 

Valve clearance could also be a problem. I wonder if your tuner replaced any lash caps, if he did, I wonder if he put the old ones back in and checked valve clearance.

 

...

 

wernt there another guy on here that somthing similiar like this happened and they were wondering if the sst ecu was trying to relearn the car and after a lot of driving car seemed to smooth out cant remember excatly but maybe something to think about if it aint the timing

 

yep search "another sst thread " atleast to see if simptoms are similiar