RB25DET Strange Timing Issues

[mabru]

I put a high tension lead in to check my timing and verified that my timing loop on the coil harness is off by 14 degrees. I set the timing to 15btdc like the FSM says and it ran like a pig, the motor also heated up quicker than normal (which sounds like retarded ignition to me). I put the light back on it and adjusted the CAS back to where the shadows from the bolts are (the original position) and it runs much better. The concern is that according to my timing light and 2 others my car is running 23 or 24 degrees btdc at normal operating temp. I don't hear any ping at all, and my SAFC is registering less than 70 at idle for the raw knock value.

When I had it at 15btdc the exhaust note was quite different and basically ran like shit until about 4000rpm. Now it runs like it should but I'm still concerned and don't trust the damned thing now, I don't want to lose a cylinder or two. The only thing I can figure is that the exhaust cam is off by a tooth on the timing belt. IIRC the teeth are approx 7 degrees per. I looked under the front cover and it 'looked' like the cams were timed right in relation to 0 on the crank but now I'm not so sure.

Anyone have any similar probs or ideas?

Thanks,

-Matt

[rob82]

Are you sure you locked the timing correctly, did the engine note change?

[wrxhoon]

A lot of timing lights wont work in the loom loop , unplug number one spark plug and fit your timing light there , that will give an accurate reading .

[mabru]

Please read the post, I did exactly that. The timing was measured at the number one plug via a high tension lead. It is accurate, and off by about 7 or 8 degrees.

[wrxhoon]

Your first post is a bit confusing , i thought you checked it on the loop at the rear.

Pull the timing belt cover off and check to make sure all the marks line up .

[RB30-POWER]

The only thing i can think of is a camshaft is out.

You said you have tried 3 timing lights already so it cant be that.

Every RB i play with, you can change the static timing anywhere from 10deg to 30deg and no real change in noise/note. When you add more timing it raises the idle a little (naturally) but other than that no real difference.

If you can get it to run like shit, by retarding the timing to 15deg btdc, something is wrong.

If it run like shit at 5deg btdc i would understand, but anywhere from 10deg btdc and up it should be very minimal the effect it has on a car just idling.

If your got high ron jap fuel and it doesn't ping maybe just leave it advanced.

If your keen to tinker, check the cam gears in relation to not only each other but in relation to the crank timing gear/TDC.

[mabru]

The only thing i can think of is a camshaft is out.

You said you have tried 3 timing lights already so it cant be that.

Every RB i play with, you can change the static timing anywhere from 10deg to 30deg and no real change in noise/note. When you add more timing it raises the idle a little (naturally) but other than that no real difference.

If you can get it to run like shit, by retarding the timing to 15deg btdc, something is wrong.

If it run like shit at 5deg btdc i would understand, but anywhere from 10deg btdc and up it should be very minimal the effect it has on a car just idling.

If your got high ron jap fuel and it doesn't ping maybe just leave it advanced.

If your keen to tinker, check the cam gears in relation to not only each other but in relation to the crank timing gear/TDC.

Yeah, I basically wanted to confirm my suspicions, the problem with buying these damned cars is you never know what's been done to them in the past. This is an RB25DET R32 conversion car and has all sorts of goodies in it, the ecu won't do diag mode tho and doesn't even have the led in the window. I'm camming it and swapping to a new turbo in about 10 days so I'll just eyeball the cam gears and hold off until the swaps and see if I can get it back to normal timing.

Thanks,

-Matt