11 replies to this topic

[oakmere]

I have fitted Schrick camshafts and the idle is not great. I hoped it would be better as I thought the idle was better with these than piper/comp cams. It is fine untill it goes into closed loop than after about 20 seconds it starts to chugg with the rev counter bumping up and down. I have a scan gauge and the fuel trims keep getting very lean if you blip the accelerator. It used to settle at -7 now it can go as high as -17. Could something else be wrong. It is a real shame as it sits at 750rpm fine for the first 30 secs. Cheers Oakmere

[TheHood]

No problems here, just ever so slightly lumpy but I do have a remap. Didn't think the ECU used closed loop at idle?

[oakmere]

I think something must be wrong. I will speak to CS first to see if the remap sorts it. If they say it should idle ok without the remap the first thing to check will be the timing. I am not sure what else it could be as the car drives fine it dose not hesitate or stutter at all once on the move and it pulls away from a standing start as standard. But at idle it is not happy once it goes into closed loop. Mine goes into closed loop about 10-20 seconds after start up once warm. Cheers Oakmere

[TheHood]

I know the duration is fairly mild, but Its still far enough away from standard to cause a choppy idle and the ECU to start throwing a wobbly with the fuel trims. I wouldn't be worried about it being lean at idle either. My remap raised the idle to about 850RPM.

[oakmere]

Just spoken to CS and they have said the idle is normally quite good with the Schrick cams. I have pulled fuse 8 and will take for a drive again tonight to see if things settle down. If not I will start by checking the timing and vac leaks.

[vocky]

I would say cam timing is out slightly

[oakmere]

I have checked the timing and it looks spot on. With the bottom pully mark lined up, the inlet and exhaust marks are at 10 to 2 with the identical number of links coming off each sprocket towards the middle As per vockys pic on the z22se chain fitting guide. So I don't think it is the timing. I enjoyed the drive more tonight with no clutch slip. It dose still chug at idle but the short term fuel trim has settled though the long term trim is much leaner now at -16 before the mods it was -8. I may remove the poly engine mount as I think this is transmitting much more vibration and I have no interior or sound insulation in at the moment. I might try some standard plugs in place on the denso iridium in at the moment as well.

[oakmere]

Feeling better tonight. The chug chug is still there but less so. I have the new gm plugs in now don't know if it is anything to do with this or not? I will be removing the uprated poly mount. It has been fine on the standard car but with the light weight fly, balance delete and cams it is not helping. When the new side mounts go I will replace the expensive upgrade.

[oakmere]

Just to update this thread. There was no problem with the engine it is just the cams combined with the light weight fly and balance delete. CS raised the idle rpm by 100 rpm, this has not improved the idle but has removed approx 80% of the vibration transmitted to the car due to the higher frequency.

[chris_uk]

You should sit in my car on tickover lol.

[Nev]

As Vocky says you only need to be out by a few degress with the timing and it can impact the idle a lot. Mine are bad too and it idles at 1100 quite roughly and doesnt settle until 1800 RPM.

[oakmere]

Nev The idle is far from bad and outside the car makes it sound better it is nothing like as bad some of the clips I have come across. My issue was the additional cab vibration but as I posted this has been sorted by the idle rpm adjustment.