laying over at 5000+ rpms...
#21
dont mean to beat a dead horse here...
To rule out fueling plot your injector pulsewidth vs RPM see if by chance it spikes or dives in the area of power loss. You should be able to connect an AFR with pulsewidth vs RPM.
If that's coming up different from good run to bad run check your Baro make sure it's not changing on you (should always be around 50-53kpa on a 2 bar, ~100kpa on a 1 bar) from when it's running good to running bad.
If you really want to get involved now would be a good time to either clamp to the header primaries or loosen the headers and install some thermocouples (ideally one for each cylinder) and see whay cylinders cool down more than others during the problem.
Aside from this.. I had 3-4 bad optis in a row (kept getting strange high rpm cutouts, misc popping, overall strange running). 2 were MSD pro billets. Dissasembled and Locktited the last pro billet and all has been fine since.
And BTW, yes they can be installed out of sync and still run (my first opti).
To rule out fueling plot your injector pulsewidth vs RPM see if by chance it spikes or dives in the area of power loss. You should be able to connect an AFR with pulsewidth vs RPM.
If that's coming up different from good run to bad run check your Baro make sure it's not changing on you (should always be around 50-53kpa on a 2 bar, ~100kpa on a 1 bar) from when it's running good to running bad.
If you really want to get involved now would be a good time to either clamp to the header primaries or loosen the headers and install some thermocouples (ideally one for each cylinder) and see whay cylinders cool down more than others during the problem.
Aside from this.. I had 3-4 bad optis in a row (kept getting strange high rpm cutouts, misc popping, overall strange running). 2 were MSD pro billets. Dissasembled and Locktited the last pro billet and all has been fine since.
And BTW, yes they can be installed out of sync and still run (my first opti).
Last edited by dookie454; 04-20-2008 at 01:01 AM.
#23
What was the a/f ratio thru all of this? To me it looks fuel related. Or your blowing the spark out. Obviously with a/f ratio u see it get real rich when u blow out the spark and you lean out if there is a fueling issue.
How much timing are you running?
How much timing are you running?
#27
Wow, I know how frustrating these things can be. I suspect the ignition system, as you do. But you seem to have looked into just about every aspect of that. One thing that was already mentioned was knock retard. Make sure that isn't what's happening by simply programming it out. If that doen't work - try running it off boost. If it runs ok off boost, I would go back to igniton. When I have seen vavetrain problems causing high rpm power loss it's usually consistent. But if it's an HR, I'd make damn sure the valves were adjusted right and aren't too tight..If it's an HR it COULD be lifter pump up, though this does tend to be pretty consistent.
Rich
Rich
#30
Are you sure that 18 degrees of timing is enough in the higher rpm range? It seems that there was another board member who was having a similar problem and it turned out that he just needed a little more timing.