RB26 Base Timing Woes

[Willy]

I've had a V44 plug-in on my RB26DETT since 2008. I recently changed my timing belt and set the CAS back to roughly the same position. The car has been driving fine. The other day I checked the timing and discovered it was 10 degrees over advanced, so I retarded it by 10 degrees after double-checking with a different timing light. Now the car drives worse than before. It hesitates coming on boost and makes much less power. I removed the top timing belt cover and confirmed the cam pulleys were correctly lined up with TDC. I also confirmed the cam half-moon shaped key for the CAS is still in position and hasn't broken off. So I'm at a bit of a loss as to where this 10 degrees of offset may have come from. Does anyone have any ideas? Oh yeah, in setting the timing, I upgraded my firmware. I think I was about 4 or 5 versions behind the current release. Would this have caused any issues? In the base timing adjustment screen, the original offset (for 10 degree ref) was -82, as set by the Vipec tuner. Now it is -96 for the timing to be right. Do either of these numbers sound about right for an RB26?

One other thing, I did change the timing belt somewhere around 2008-2009 after the Vipec install and tune. I went back to the workshop and they checked the timing and adjusted the offset from -80 to -82. I was wondering in my head if the timing belt was always off by 1 tooth, but the fact I've changed the belt once already and it made minimal difference to timing, makes me think the possibilities are very slim.

[Steve]

Do you use some kind of loop on the coilwiring to hook up your light, or are you hooking up a sparkplug wire between the coil and plug? You should do the later as a "loop" usually is highly inaccurate.

[Willy]

Yeah I used the factory loop at the back of the engine, although I also tried one of the wires to the coil pack and got identical readings. I haven't tried putting a lead between coil pack and spark plug.

[Simon]

When setting the timing the stock loop will give issues when setting.

It is best to fit a short HT lead and time off that.

[Willy]

Solved it! You guys were spot on. The old timing loop problem strike again. I found a bit of ignition lead and connected it between the coil and spark plug, then set the timing off that. Believe it or not, it was 9 degrees off! Previously I had tested the timing loop on the little timing wire loop at the back of the engine, as well as on the low voltage wires on the back of the coil. Both of these gave identical readings. Nissan must have some fancy timing light or something. I'm pretty sure the Vipec mechanic used the low voltage wires on the back of the coil, but maybe he had a better timing light than mine.

 

The car is going damn well now. Very happy. Thanks for your help guys.

[Steve]

Just remember that if the car was previously tuned 9 degrees retarded, and you now advanced it 9 degrees your timingmap is now 9 degrees advanced all over. Also under WOT. 9 degrees advanced under high loads is alot and you need a retune.

[Willy]

It's fine now. I never had the car tuned while the base timing was incorrectly retarded. It was only retarded last week for a few days when I incorrectly adjusted timing off the loop. You're right though. 9 degrees makes a massive difference. It drives 100% better now.

[Dave Kriedeman]

Hi everyone,

I do a lot of Skylines and Nissan's in general.

Below is a list of the most common things I find with timing issues and software settings when setting up Nissan timing,

1. Always remove the coil and fit a HT lead from the coil to the sparkplug. (DON'T USE THE TIMING LOOP AT THE REAR OF THE CYLINDER HEAD).

2. Don't use dial back style timing lights.

3.Nissan coils have a very high failure rate and or misfire rate, sometimes due to HT spark firing from the primary/secondary winding cover to the mounting bracket that runs through the guts of them, this causes erratic timing gun firing and inaccurate readings.

4. Remember that the timing mark that is last on your left when looking at the balancer when the engine is cranking over is the TDC mark , the first to come around on your right is the most advanced mark.

Each mark represents 5 degrees.

5. I always personally move the CAS so that the 3 bolts are dead centre of the CAS adjustment slots.

6. Turn off the fuel ( set from sequential to off).

7. Calibrate triggers, always carry out the TEST ECCS first, keep cranking until a value appears in the box..

8. DONT FORGET TO TURN TEST ECCS OFF after setting.

9. Make sure battery is fully charged and start cranking, set lock timing to 10 or 15 degrees does not matter, adjust offset in the software to correct the timing, DO NOT MOVE THE CAS.

10. Turn the fuel setting back from OFF to SEQUENTIAL.

Allow engine to warm up, hold engine speed at approx. 2000 - 2500 rpm when warmed up and recheck the ignition timing with the timing lock, I normally set the lock timing value to 20 -25 degrees so the engine will rev at that rpm .

11.Once you are happy with the accuracy of your timing, perform an IGNITION DELAY test, rev the engine and adjust the delay to eliminate ignition drift.

12. On a fresh installation also check your sparkplugs are not heavily carbon fouled or wet as this will make setting your timing correctly a nightmare.

Regards

Dave.

Edited April 27, 2016 by Dave Kriedeman