Drax240z Posted October 3, 2004 Share Posted October 3, 2004 I'm getting close to pulling my hair out here! I can't seem to get my new engine to rev up without detonation... it's driving me batty. F54 block/turbo pistons N42 head Turbo Cam Big NPR intercooler Walbro pump 440cc/min injectors SDS EFI 8.3:1 CR I've swapped from my BPR6EY-11 plugs to BR8ES plugs, and that seems to have helped the ping slightly. Timing is currently 12* idle, all in to 36* by 3000rpm. Boost retard is significant at this point, 1.5* retard per PSI to a maxium of 16*. Using the wideband my air fuel ratios are 12:1 or richer across the board. Still I am getting ping on the top of 2nd gear. I've varified my timing with a timing light too. I seem to be fine until about 5psi boost where the pinging is audible. Can someone think of something I am overlooking? I am running 94octane gas... I think I might put some more in to dilute whatever was left in my tank 3 weeks ago when I parked the car to do the engine upgrades. Here is a log of my last run: Red is MAP, Green TPS, Pink AFR, Black RPM. This pull is from first gear at a dead stop. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted October 3, 2004 Share Posted October 3, 2004 Hmm..I started my timing at 20* onmy SDS and ramped up to a total of 32 I believe by 3500 rpm's. Everything else sounds normal. The extra compression may need a little less timing. It seems a good place to start anyway. Quote Link to comment Share on other sites More sharing options...
clint78z Posted October 4, 2004 Share Posted October 4, 2004 Um your problem point seams to be a 4:10. This is your highest map reading, I don't think that the increased compression ratio is directly causing this. I would sneak back the fuel at that map point since it seams to run well at about 11:5/1, I think that it is too rich and can't ignite properly. Acceleration runs aren't the best for tuning, stabilize you points at a constant load cell it tells more about what is going on. Start with the lower load cells and work up. Be careful !! Quote Link to comment Share on other sites More sharing options...
240hoke Posted October 4, 2004 Share Posted October 4, 2004 i dunno whats causin your detonation but i would add some more fuel in the two high spots, try and get the afr's to a solid 12. also might be better to do a 3rd gear pull also i also ramped my timing from 20-32 degrees oh, is the pinging audible?? Or is your sds knock sensor picking it up, ecause i could NEVER get my knock sensor to work right, i guess the L is jsut no smooth enough lol. I jsut turned my knock sensitivity al the way down and told it not to retard the timing at all. -Austin Quote Link to comment Share on other sites More sharing options...
Bernardd Posted October 4, 2004 Share Posted October 4, 2004 How much boost is 3.13 volts? That's the exact same rpm that I have difficulty with. Major richness (you're already there) and reduced timing got rid of my knock in that area. I don't know much about the sds but can you reduce timing in a specific load area? You may also want to add fuel/reduce timing just before the knock occurs. Check that: I re-read your post and at 5psi I can't see why you'd have a problem. I can run 12:5 afr's no problem with low boost , my problems occur at 15+psi. Are any of your plugs white? Perhaps an injector is clogged or something. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted October 4, 2004 Author Share Posted October 4, 2004 Hrm, the areas you guys see that are lean are corresponding to the 1-2 shift, and 2-3 shift, ie: I am lifting off the throttle to shift. Under all loads the AFR is 12.5:1 or richer on this log. Clint you are suggesting that I am too rich, however, I started in the 12.5:1-13.0:1 range and richened it up from there to try to get rid of the pinging. Highway driving the car feels fine, it is ONLY under boost that I am having issues at all with tuning. I am not using a knock sensor, the ping is audible indeed. Plugs are not lean white, and are equal across all 6 cylinders. O2 sensor came out black as night after relatively little time running in the car, it's certainly rich... as the AFR's indicate. As I see it, the options are this at this point: A) My initial timing is somehow mucked up and am I running more timing than I think I am. I am hearing something rattle that sounds exactly like detonation, but only happens under boost. That's all I can come up with at this point... I think I'll verify my timing marks, maybe somehow they got messed up in the rebuild. Quote Link to comment Share on other sites More sharing options...
clint78z Posted October 4, 2004 Share Posted October 4, 2004 Using the brakes a bit to stabilize a loadpoint on a map, that way there is no accelration enrichment. Did you try decreasing the plug gap, checking wiring and grounds. Have you any way of checking the intake air temp at this point. Might be useful to log that one instead of TPS. I love my LM-1, how do you like AFR chart vs load and rpm. I showed Klaus that one I did on excel, and he was nice enough to stick it in. Customer Service rocks !! Quote Link to comment Share on other sites More sharing options...
Drax240z Posted October 4, 2004 Author Share Posted October 4, 2004 Yeah I can log intake air temp, might be worthwhile to add that channel as well. Plugs are gapped at .032". Haven't played with my LM-1 a ton, but it's got some really nice features. I'm slowly learning how to use them to my advantage. Quote Link to comment Share on other sites More sharing options...
clint78z Posted October 4, 2004 Share Posted October 4, 2004 Hey Drax can you send me a copy of your logs so I can have a look at them using my LM software, I am intrested in zooming in on that problem area, some of the advanced features are handy in analysing things. My email is clint78z@yahoo.com Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.