or so says the ECU.

Car is a 98 GSR. Engine has a set of JDM ITR cams. It is otherwise stock. I've since done the valve adjustment three times, adjusted/checked timing twice, and replaced the spark plugs.

I have two problems though:
1) the car will sound like a diesel occationally when it is under load.
2) the car will throw a Running too rich code(based on the ODB II scan tool).

Any ideas why it's doing this?

O2 could be bad, but wouldnt it just throw a bad O2 code?

thanks,
-S

 

my guess would be timing

 

You shouldn't have any problems running R cams in a B18C, we do it all the time without any problem what so ever so it may just be a bad oxygen sensor. No other CEL tho? If possible I would try swapping it with a known good oxygen sensor for a bit. See if the problem comes back, if so then it's something else. You're just running a stock ECU, correct? Good Luck

 

Yes, everything is stock - ECU etc.

I guess I have to shell out for the O2. It's just that everything was fine before the swap. Car ran great.

Timing is at 16* TDC right now.


The thing is, I am not so worried about the richness - rather it's the noise I am worried about. I at first thought it might be knocking.. but then I am running rich. Can you run rich and continue to knock/ping?

-S

 

and you're positive that your timing belt is perfectly timed and not couple tooth off ?

I'd be more concerned about the diesel sound sunder load, prolly could be valve/piston tapping from incorrect engine timing.


greg

 

Yes. Everything(timing mark on the gears) lines up correctly when I am doing the valve adjustments.

The odd thing is, the sound doesn't always happen even under the same load situation.

 

my valves tap fairly loud with my zex stage 2 cam in my y8. This is mainly because of the high lift the cam has though. when I first installed the cam i adjusted the valves all crappy because I wasn't sure how tight a "slight drag" really needed to be. Now I have them adjusted right, but before that it definantely sounded like a diesel truck or something. Now my valves are much quiter, but still louder than stock...thats just from the cam though. So make sure you are adjusting the valves correctly.