Subject	Diagnose this...while road racing 2 weekends ago, i noticed
Posted by	sawbonez on November 28, 2012 at 7:11 PM
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Message	a few episodes of overboosting to +- 20 psi, engine conservatively tuned to 20 psi on 100 octane. 30 min race ambient temp around 45F all was well. second session... after 20 min, sudden loss of 25% power. i quit the same lap parked the car. data as follows: no smoke, no abnormal noises, did manage 125 mph just prior to pits even with power loss, so no evidence of a "catastrphic failure" boost leak test= no significant leak #4 cylinder "dead" per power balance test electrode totally burned off #4 spark plug #4 coil pack good #4 injector nominal ohm resistance #4 injector has power from battery #4 injector harness in continuity with ECU harness ECU codes detonation sensor 14 times as expected... MAF code 9 times 555cc injectors and wiring harness 5 years old as i don't have an easy or efficient way to test the flow of the injector, my plan is to replace the injector first then evaluate both MAFs... i think the root cause of the lean condition in #4 cylinder is low fuel secondary to failed injector
Follow Ups	Diagnose this...while road racing 2 weekends ago, i noticed - sawbonez 19:11:30 11/28/12 Jeesh! Keep us posted. - OverZealous (CT) 20:06:49 11/28/12 I would do a compression test and check with a flashlight - Krazyd27(Houston) 08:04:53 11/29/12 top of piston looks ok, compression test pending i have - sawbonez 08:16:05 11/29/12 Yes get a look inside # cylinder. (n/m) - craigz96tt 08:10:48 11/29/12 Could be as simple as a faulty spark plug that just - MixManMash 10:07:59 11/29/12 ngk bkr7eix (n/m) - sawbonez 13:52:36 11/29/12 Sounds like maybe your MAF signal failed, allowing - TriniTT 11:22:35 11/29/12 ok - aliaZ 19:07:19 11/29/12 hmm...i don't think my car will do 145-150 mph in safe mode - sawbonez 07:08:17 11/30/12 That turn is when your MAF connector lost connectivity. (n/m) - TriniTT 13:56:32 11/30/12 got it now....i'm a little slow.. so my plan is as follows: - sawbonez 16:05:15 11/30/12 Just start with the compression test, it'll save time & $. - TriniTT 16:28:38 11/30/12 last time i killed a spark plug it took out my valve too. - Dane (Houston) 16:14:41 11/30/12 you can sort of flow test a injector in car - Dane (Houston) 16:25:01 11/30/12 you guys make me want to have a bone fire party with my - sawbonez 16:44:45 11/30/12 high EGT's due to retarded timing since you were running - ztunerz 10:32:48 12/01/12 thanks harry (n/m) - sawbonez 12:40:23 12/01/12
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