SORTING RULES - MISFIRE AT START-UP / ROUGH START COMPLAINTS (P0316 MISFIRE DETECTED ON STARTUP, FIRST 1,000 REVOLUTIONS) PulsCar analysis of NHTSA public data, October 2026. License: CC BY 4.0 Fingerprint of the rules text below, taken when it was written and before any complaint was sorted: b0adef144cee3727d0815a42bbce6a16026d0354d84b141d6c6e71def168ec8f (2026-10-28T15:39:00Z) [Changed when published, wording only, so that the file reads on its own: the title line moved up; the file name of the sorting rules and of the search list replaced by plain words; one phrase about sending narratives on for sorting reworded; one word in the description of category F replaced by "reprogramming". No rule changed.] Written before any complaint in the set was sorted. ## Pool (how the complaints were found) NHTSA complaints received 2015-01-01 to 2026-10-04 (the latest received date in the flat files). A complaint is in the pool if its narrative matches any of the following case-insensitive text searches: 1. R1 - the code P0316 by any spelling (letter O for zero, a space, hyphen or period after the P, suffix 00), or a bare number after a code word: `(? N. - R2 coils or plugs or injectors replaced together with no single part named: sorting-rules order C, P, I, A, M decides. A "tune-up" (plugs and coils) -> P if plugs are named first, else C. - R3 a part replaced but the owner says the symptom stayed or came back and no other cause is named afterwards -> U with returned=yes (a part that did not help does not count). If a later different cause is named as the fix -> that cause's letter with returned=yes. - R4 a shop/dealer diagnosis, estimate or quote that names a part as the cause counts as the named cause even if the part was not yet replaced. - R5 carbon build-up on intake valves or in the combustion chamber, burned oil, low compression, valve or head problems -> M; fuel injector deposits/leaks, fuel pump/pressure, bad gas -> I; vacuum/intake leak, sensors (crank/cam/MAF/MAP), wiring -> A. - R6 recall flag = yes only when a recall/campaign/TSB/special coverage/software update is tied to THIS fault or this event; an unrelated recall mentioned in the same narrative -> recall=no. - R7 stall flag = yes only when stalling, loss of power or limp mode is stated in the same event as the misfire/rough start; a failure to start alone is not stall. - R8 flash = yes only when a flashing/blinking check engine light is stated for this event. - R9 startonly = yes only when the narrative says the uneven running happens at start-up / cold / first seconds-minutes and clears or is much better when warm or after a short time; "also happens while driving" -> no. - R10 returned = yes only when the same light, code or symptom is stated to have come back or not been cured after a repair or reset. When the excerpt does not settle a point: the narrower reading (flag no; category U). - R11a a stutter/shudder "when starting" that the shop or dealer attributes to the transmission, clutch or mechatronic unit, with no engine-misfire wording -> N (not an engine start-up misfire). - R12a a cause stated only by the owner (own research, forum, parts-store scan, own reading of coolant or oil) with no shop/dealer/mechanic naming it -> category U, never M/I/P/A. - R13a returned=yes when the narrative says repair/service attempts on this fault were made and the fault persists ("no successful repair", "not resolved despite visits", "still present"); a check that merely found nothing -> no. - R14a category F only when a software update/campaign is stated as performed AS THE REPAIR for this fault; a campaign that came before the symptom, or a fix still pending -> U. - R15a dealer/shop only cleared or reset the code, or found no code/fault, and named no part -> K. - R16a pasted or quoted TSB/code-list text with no statement that THIS vehicle had the symptom -> N (all flags no). - R17a warning light or misfire code noticed "when started" or "in the morning" without a statement that the engine ran unevenly at start-up -> N (R1). - R11b a TSB / bulletin / lawsuit text quoted by the owner (P0316 only in the quote) with no statement that THIS vehicle had the start-up misfire or rough start -> N, all flags no. - R12b a cause stated only by the owner (own research, own theory, "I found out", parts-store or own scan) with no shop/dealer/mechanic naming it and no part replaced -> U, never M/I/P/A. - R13b stall = yes only when an actual stall, shutdown, dying, loss of power or limp mode is stated for this vehicle; hazard talk ("could stall"), "tries to stall", hedged "potentially" -> no. - R14b a symptom the dealer blames on the transmission: if the owner also says the engine itself runs rough/shakes/buzzes at start -> O; if only stutter, shudder or jumping gears -> N. - R15b startonly = yes only if the narrative says it clears or settles (warm-up, seconds, restart); bare "rough on cold start / in the morning" with no clearing -> no. - R16b recall = yes for a TSB, campaign, software update or warranty extension tied to this fault (performed, offered, refused, asked about); class actions, recalls of other markets/vehicles and unrelated recalls -> no. - R17c stall=yes when the engine is stated to shut off / die / stall by itself after a start attempt or at a stop (a pure no-crank or no-start is still no). - R18c a cause the shop only "might"/"suggests"/"could be" is not named: category U (K if the shop is stated to have found nothing). - R19c startonly judged on the start-up symptom itself: a later separate failure not described as misfire/rough running does not cancel yes; a misfire while driving (e.g. flashing light) does. - R20c stall=yes needs power loss/shutdown in the same event as the fault; reduced power in a later separate event, or hedged ("seems", "like it was"), -> no. - R21c a rough/rumbling/grinding SOUND at start with no shake, shudder or uneven-running statement -> N (all flags no). - R22c a dealer "known issue" remark, an owner saying no recall exists, or an unrelated recall (e.g. Takata) -> recall no. - R23c text cut right before the outcome of a repair -> category as named so far, returned no. - R17d stall=yes also when the same event states lost power, limp/reduced power, a stated speed cap or forced idle; "failed to accelerate" alone, or a power loss on a separate occasion/day, is not stall -> no. - R18d stall=yes when the engine shuts off, dies or will not stay running right after the rough start (same event); a failure to start alone is not. - R19d a shop/dealer that checked and found no leak, fault or code, named no part and repaired nothing -> K even when the owner guesses a cause (extends R15a). - R20d an owner-only observation (low oil or coolant, own scan, forum, "common problem") with no shop naming the cause -> U (extends R12b). - R21d a shop names two parts together with no single one tied to the misfire: sorting-rules order C, P, I, A, M decides; if one is tied to the misfiring cylinder, that one decides. - R22d a hard start, no-start, rattle, exhaust or other noise/vibration with no statement of uneven running -> N; a web-address slug quoted by the owner is not the owner's statement. - R23d a shop only observed a condition (coolant pooling) without naming it the cause, or the outcome is cut off in the excerpt -> U. - R24d recall=yes only when a recall, campaign, TSB or warranty extension for this fault was performed, offered, asked about or refused; a bare "no recall", "known problem" or quoted lawsuit text -> no. - R25d flash=yes only for a flashing check-engine light; other flashing lights (gear indicator, service lights) -> no. - R26d startonly=yes also when the owner says a restart / key-off-on clears it. - R27d returned=yes when a reset or earlier repair is stated and the same symptom then came back; a new symptom after a repair, or an unstated outcome -> no. ============================================================================== RULES OF THE CONSISTENCY CHECKS (the resolution column says "changed in consistency pass" for the complaints they changed). Rcons1: a first check, from the same excerpts, of the 170 complaints sorted as a coil, plug, injector, air/sensor/wiring or engine-mechanical cause with returned = yes (33 changed). Rcons2 and Rcons3: a final check on the FULL narratives, because the two sortings first saw only an excerpt of about 300 characters either side of the matching words; it re-read 856 complaints, every one not sorted as engine mechanical: those sorted to a cause other than engine mechanical, plus all those with no cause stated, and 135 changed under the written rules below. - Rcons1 consistency pass: when the cause or part named by the current letter was replaced/repaired/treated and the problem is stated to have come back or persisted, and no later different cause or fix is named, the category is U (returned stays yes). - Rcons1 if a later different cause or fix is named after that failure, the category is that cause's letter. - Rcons1 if the named cause is the last cause or repair stated, or the excerpt is cut before the outcome, the current value is kept. - Rcons1 (pass 2) consistency: the part or cause named by the current letter was replaced/repaired/treated, the problem is stated to have come back or persisted, and no later different cause or fix is named -> U (returned stays yes). - Rcons1 a later different cause or fix named after the failure -> that cause's letter. - Rcons1 a cause the shop only says "could be/might" is not named (R18c); an owner-only cause is not named (R12b). - Rcons1 if the named cause is the last cause or repair stated, or the excerpt is cut before the outcome, the value is kept. - Rcons2 final-cause pass on full narratives: when the full text names a later or final cause (coolant leak into a cylinder, cracked block or head, head gasket, - Rcons2 engine / long block / short block replacement, timing chain, valve or head problem) after the part named by the current letter, the category is M. - Rcons2 the same final-cause rule applies to I, A, O, K, U: the last repair that fixed it, or the last cause a shop named, decides. - Rcons2 a part that did not help does not count; returned is set to yes only where the narrative states the symptom came back or persisted. - Rcons2 a cause only the owner suspects, or a hedged "may/might" cause, is not named; the current value is kept when no later cause is stated. - Rcons3 final-cause pass on full narratives of complaints coded U: when the full text states a cause or repair that a shop, dealer or mechanic named (or that was carried out and not stated to have failed), the category is that cause's letter. - Rcons3 head gasket / coolant into a cylinder / cracked head / engine or long block replacement / valve or timing-chain finding named by a shop -> M; fuel pump or injector -> I; sensor -> A; shop checked and dismissed it -> K. - Rcons3 a part replaced that the narrative says did not help, a cause only the owner suspects, a hedged cause, or a campaign performed before the symptom does not count: the value U is kept. - Rcons3 full-text final-cause pass on complaints coded U: the last repair that fixed it, or the last cause a shop/dealer/mechanic named, decides the letter. - Rcons3 coolant leak into a cylinder / cracked block or head / head gasket / engine or long block replacement / cam phaser / rod bearing named by a shop or dealer -> M. - Rcons3 fuel injector or fuel pump named by a shop or dealer as the cause -> I. A shop or dealer that checked, could not reproduce or found nothing and named no part -> K. - Rcons3 a cause only the owner suspects or a hedged "may/might" cause is not named; a named part replaced without cure and no later cause stays U; no cause in full text stays U. - Rcons3 full-narrative pass on complaints coded U: the final cause or repair stated in the FULL text decides the letter. - Rcons3 a shop/dealer/mechanic diagnosis or quote naming coolant in a cylinder, a bad engine/long block/short block, head, cam/lifter/timing or a replaced engine -> M. - Rcons3 a dealer/shop that tested and found no fault, or could not duplicate, and named no part -> K; a bad injector/fuel pump part replaced by a shop -> I. - Rcons3 a cause only the owner suspects, a hedged "may/might" cause, a pending inspection, or a recall without a stated repair: U is kept. - Rcons3 final-cause pass on full narratives (I, A, O, K, F): the last cause or repair that a shop, dealer or mechanic names decides the category. - Rcons3 a coolant leak into the engine, a bad engine / long block, or engine damage named after the current letter -> M. - Rcons3 a part named by a shop/dealer after a K (checked and cleared) -> that part's letter. Owner-only guesses and hedged causes are not named. ============================================================================== THE TEXT SEARCHES AS WRITTEN (case-insensitive; the first search is the union of R1, R1p, R2 and R3) R1 (code): (?