Brad May Posted December 29, 2017 Report Share Posted December 29, 2017 Hi there, heres the setup I have... LS1 with cam, 6/71 blower with 8 injectors above firing on semi sequential. Waste spark setup. Had this running fine with a turbo, but now it seems to be misfiring and fouling alot even with a decent AFR. I did the spark test, all are sparking, however this may be where the problem lies.........sometimes when I would go to test the spark in spark test mode by changing from off to on, it would prime the fuel pump all of a sudden. Im guessing I have a wiring problem? or possibly sharing a power feed between fuel and spark that i shouldnt?? Any help would be appreciated. thanks Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 29, 2017 Report Share Posted December 29, 2017 Sounds to me like maybe a trigger error caused by ignition noise. Can you try to capture the misfire in a log: https://www.youtube.com/watch?v=_P1LRANeO4A Quote Link to comment Share on other sites More sharing options...
Brad May Posted December 29, 2017 Author Report Share Posted December 29, 2017 Ok thanks, will be a couple of days before I can. Cheers Quote Link to comment Share on other sites More sharing options...
Brad May Posted December 30, 2017 Author Report Share Posted December 30, 2017 Heres a quick log I managed to get, note there is TPS input from me as cold start with no IAC etc. Thanks Bradley LogLS1blower.llg LS1blower.pclr @Adamw Quote Link to comment Share on other sites More sharing options...
Brad May Posted December 31, 2017 Author Report Share Posted December 31, 2017 On 30/12/2017 at 6:03 PM, Brad May said: It's possibly more of down a cylinder rather than a misfire, but hopefully the log can rule out things like crank and cam sensor signals? Heres a quick log I managed to get, note there is TPS input from me as cold start with no IAC etc. Thanks Bradley LogLS1blower.llg LS1blower.pclr @Adamw Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 2, 2018 Author Report Share Posted January 2, 2018 Hi Adam, I have emailed the log to the tech email since I see your on holiday. Here's a question you may be able to answer while relaxing in spa, just a thought, but I just tested resistance on the new leads on it, obviously being ls1 they are short, but they have close to no resistance (not solid core either). Could this be interfering with signals? My old leads had alot more resistance. Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 2, 2018 Report Share Posted January 2, 2018 Hi Brad, I haven't been able to download your log, not sure if I have an internet problem here or if your attachment isn't working but never mind. could you try sharing them via OneDrive or google drive etc? Wasted spark ignition often creates a lot of electrical noise so with low resistance leads I would defiantly have some suspicions of this. Have you still got your old leads to try? Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted January 2, 2018 Report Share Posted January 2, 2018 Had a customer call about similar issues with another branded ecu last week. He was using non resistor plugs which generate huge electrical noise. What plugs are you using? Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 2, 2018 Author Report Share Posted January 2, 2018 Thanks guys, plugs are ac delco 41-805 which Google's as resistor type. I just got some new decent leads instead of the Chinese ones, so will see how I go today otherwise I will try share the tune another way Adam. Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 2, 2018 Author Report Share Posted January 2, 2018 Ok, so as excited as i was still no luck. Here's where I am so far...... Spark plugs are resistor type New Bosch leads spark tested every cylinder - all ok compression tested every cylinder - all ok run it for a couple of minutes, definitely down a cylinder or two, AFR was showing on the leaner side, pulled plugs, 7 & 8 wet, rest lightly fouled. Swapped 7 & 8 coils around with 1 & 2 thinking it was the coils, re run for a minute and pulled plugs. No wet plugs, but all completely dry fouled. This motor run perfect with the turbo setup, then I put the blower on, so the only difference is the injectors are now on top of the blower, left as semi sequential firing. Also relocated the coils from the inner guard back to the original rocker cover position. The fuel map should be pretty close since it was good before. The wideband is in one bank only, and to be honest their is a slightly bad leak in the v-band which is a couple of inches further past the oxy sensor which I know doesnt help. I sent the logs to TECH and they replied today saying the accel enrichment was terribly high and to lower that, but it used to be fine and hasnt been changed? Any more ideas?? @Adamw I have just uploaded log to onedrive, do I need your email or user name to share? Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 3, 2018 Author Report Share Posted January 3, 2018 Just thought of one more thing that I did change, I put a different cam in it, could this affect the cam sensor? Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 3, 2018 Author Report Share Posted January 3, 2018 back again..... so the engine was very sludgy inside (previous owner!) so I thought that possibly the cam sensor was sludged up. Just tried to remove it to clean, and the makers of the blower intake obviously dont take this into consideration. it will only come half out before fouling on the intake manifold. I chucked it back in and just tried to start the car again, after fiddling with the cam sensor now it wont start at all, nearly catches but wont, and nearly blew the exhaust to bits with the backfires it was doing..........so Im guessing I have a crook cam sensor? Anyway, by the time someone replies I will have the blower and intake apart and off so I can get to the cam sensor for replacement. Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted January 3, 2018 Report Share Posted January 3, 2018 Did you try to run a scope trace of the crank and cam sensors? Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 3, 2018 Author Report Share Posted January 3, 2018 unfortunately no, but the trigger error counter started increasing the last time I tried to start it. Half way through blower removal now, so will replace cam sensor and see how it goes. Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted January 4, 2018 Report Share Posted January 4, 2018 So you did say you changed the cam ? Is the cam sync in the identical place as the old cam ? Did you re-check the trigger offset when the engine was reassembled ? Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 4, 2018 Author Report Share Posted January 4, 2018 Yes changed the cam and never rechecked offset etc. Just in buying a new cam sensor now, might as well so I don't have to remove blower and intake again. I just "assumed" the sync would all be identical Quote Link to comment Share on other sites More sharing options...
Ken Dunkley Posted January 4, 2018 Report Share Posted January 4, 2018 Never assume - It makes an ASS out of U and ME . LOL . I thought id bring it up as it was running before and its one thing you have changed . I dont know if its positioned identically to the original but worth checking since you are have trigger probs . Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 4, 2018 Author Report Share Posted January 4, 2018 Jeez I hope its the same. Cam sensor here tomorrow so will chuck it together and see how it goes. Might just have to chuck a distributor and carbs in it instead! Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 5, 2018 Author Report Share Posted January 5, 2018 Update.... New cam sensor in and nope that didn't fix it. Still trys to catch starting and exhaust backfires Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted January 5, 2018 Report Share Posted January 5, 2018 From here i would turn the fuel mode off in PCLink and re sync your timing offset. Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 6, 2018 Author Report Share Posted January 6, 2018 Im still getting trigger errors when cranking so I'm guessing its one of the listed problems like sheilding, grounding etc. As the Atom does not support scope for the triggers I may have to drag it into a shop to get checked out Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted January 6, 2018 Report Share Posted January 6, 2018 You can try turning the ignition mode to off to see if it is the ignition system causing the noise on cranking. Quote Link to comment Share on other sites More sharing options...
Brad May Posted January 6, 2018 Author Report Share Posted January 6, 2018 Well it's going now, what I thought was an over rich mixture was severly lean, and ruined plugs. New plugs and 25% more fuel and it's running great again, well until a proper tune. Can't believe it was so simple Quote Link to comment Share on other sites More sharing options...
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