slaughter2k

Hi, no, It's still not in closed loop. I just adjusted the maf voltage by hand until the external wide band o2 sensor showed adr 14.7 in idle. That's it. The narrow band o2 sensors from the ecu also reacted during hand adjustments. (jumped from rich to lean when i was near 14.7 as they should). but everything in open loop, no automatic fuel adjustments. --> currently it looks like he really needs that ammount of air and gas at correct afr to maintain 700rpm idle ?

My durametric (old one) has no button for ecu reset, just for failure code delete. I will check O2 and fuele trim values after disconnecting/reconnecting the batterie. What I did today: Soldered a potentiometer into maf signal line to manipulate the voltage to get 14.7 afr in open loop. What to say...O2 sensors (wide band external and regulating sensors) reacted immediately. Adjusted to afr 14.7 (was just a very minor amount of adjustment) and got 700rpm 2.7ms injection (accurate measurement) Afr ~14.7 (accurate measurement) 18kg/h maf (hand adjusted via potentiometer) 2.4% engine load 2% throttle (accurate measurement) This looks like I have an increased amount of mechanical load at the engine or maybe a compression or timing issue (??!!) What I'll do tomorrow is trying to get rid of the sai failure code and reinstalling sai pump relais (maybe this is preventing closed loop mode) MAF: guess it is giving reasonable values, even if they might be a bit off intake temp: confirmed with reasonable values via durametric coolant temp: confirmed with reasonable values via durametric, CPS: new sensor installed, no codes any more (still suspicious due to aasco flywheel) cam sensors: just one in row engine but this gives me 3-4deg. offsett: Should be ok O2 sensor heater: sensor are perfectly responding on maf modication and coast mode. Bad heater should also throw failure code O2 sensor: similar too heating knock sensors: that's something good I wanted to check but don't know really how to. Will upload a engine running video for you

Hi, detailed feedback...thanks for that. first: yes, displacement is still 2.7l Because of smooth flow I already thought of installing a grate from an other MAF to smoothen the air flow Problem with the CKP was that the shutter wheel from the aasco flywheel was not accurate. In addition the distance "aasco shutter wheel to the ckp sensor" was 0.8mm bigger than "stock flywheel shutter wheel to cpk sensor". After measuring and correcting nearly all teeth of the aasco shutter wheel the CKP failure code was gone. I red from 4 adaption values in bosch me 7.2 technical documentations. But I did not find anything how I can delete this adaptions for the porsche ecu. As I red from many boxsters running fine with aasco flywheels I hope I can exclude this suspicion that the open loop issue is localized here. Evap system is an influence but it should be visible at the fuel trims somehow. My ecu does not make any attempt to regulate nor highlighting a failure code. My big suspicion is also that he is stuck in open loop because of anything which he is not seeing as a reason to highlight a failure code. I already found your linked thread and was excited first. During reading it again I found out that the immo problem and the open loop problem was not related to each other. The open loop problem solution has not been diskussed unfortunately. I will check now: - loop status (open, close) - a different maf housing and a grate - suspicious ecu pins with open wires from harnes stripping - ...

summarized idle values and a MAF plausibility calc. that I did some days ago based on any 996 3.4 porsche dyno log I found in the web (for sure don't know the accuracy)

Should have summarized them accurately before...modifications: - Aasco light weight flywheel - 2.7 987 inlet manifold adapted - 996 plenum (t-pipe) with 996 throttle - straight intake piping through the fire wall into rear trunk - original MAF housing (cutted from org. air filter housing) - Filter cone (slightly oiled for prevent contamination of MAF) - deleted SAI (completely. closed also the head bores at the manifold flange) - complete new exhaust (equ.length headers, 200cell converters, new O2 sensors - low temp thermostat - underdrive pulley - new ckp sensor with controlled gap (1mm --> had "signal below threshold" failure before) - vaccum port at plenum / throttle closed - crank case evacuation via exhaust and moroso valves - tank venting and charcoal canister system removed completely - left tank vent valve, SAI pump and SAI valve attached to prevent ecu failures for now (no failure codes currently except SAI pump) - new spark plugs and coils - 986 2.5 liter transmission - stripped wiring harness. Removed all wires which are not needed including all relays. (nothing engine related should have been cutted) - hm, that's all I guess beside mechanical maintenance and slight improvements Not changed/touched: - stroke - ecu mapping (for now) - MAF housing diameter or MAF itself --> I will post some detail pictures of modifications in about four hours

Anyone has any advise? Don't know what to do else: Ecu is not adapting fuel trims and retards timing over 4k rpm

made a 3rd gear wot yesterday with a wide band O2 sensor on board. Idle is running at afr 12.9, wot at 10.5. Ignition angle is retarded at 4100 rpm ? I guess there is an additional major issue.

Update: original throttle installed. Engine not stalling any more on traffic lights when warm. Fuel adaptions will still not performed ?. Engine running rich. Problem 1 solved, problem 2 pending Remark: Reinstalled 996 throttle again with success. Issue was that I mounted it initially 180deg. rotated which caused stalling when warm :) -->what issue will not stored as a failure and might block fuel adaptions? Any ideas?

temp sensor values checked at room temperature. Btw: I couldn't find the coolant temp after radiator. Engine temperature is "engine coolant temperature", correct? Plausible... just re-adapting the original throttle

Update: today I installed the post cat O2 sensors because I read that missing O2 sensors are triggering a rich save mode. --> no change. No fueling adaptions, engine still stalling when warm. Tomorrow I will adapt the smaller original throttle body to the bigger 987 manifold. In addition I read that a unplausible fuel pump status might also cause injection time elongation. Bosch me 7.2 system description (based on landrover) Edit: I forgot to check coolant and air temp today, will do that tomorrow prior throttle body change.

I just ordered two post cat o2 sensors to complete the system again. Aditional comment: I disconnected the complete secondary air system including electric valve. Might be an issue? picture shows idle and 3000rpm. MAF values makes sense, O2 voltage goes down when engine costing down. Injection graph is normal?

codes cleared with durametric. No, both more or less: FRA RKAT values are completely frozen. O2 sensor value is moving very little (0.85-0.86V). No swinging as it should (also not when switching to the visual mode/ graph). Calibration is done...know what you mean. Btw: throttle pos. at idle is 1.6%. FRA RKAT is the same for bank 2 thanks for first help ?

Hello Porsche enthusiasts ? My first post so I give a short introduction. Have a 2001 986 2.7 and am from Germany. 986er is completely stripped for track use. I rebuild nearly the complete engine and did also some modifications. The point: - Durametric log shows rich mixture (o2 sensors at 0.85V confirmed by wide band sensor) - FRA is sticked to 0.99 even after battery disconnection - RKAT is sticked to 0 even after battery disconnection - injection time is higher than spec with 2.7ms (spec 2.2ms) - MAF is ok with 17.8 @ idle I guess - comment: warm engine stalls sometimes at traffic lites, MAF is original, engine running in general OK modifications: - lightweight flywheel - 996 throttle body - race cat with new exhaust (because of this there is currently no post cat o2 sensor connected) Hope someone of you has a hint for me. I hope my ECU is not toasted ? (due to frozen FRA RKAT value)