Horribly degraded performance

Being that you have the URD MK3 kit, and now on the HPTUNERS, have you had the ECU reflashed for the TRD S/C calibration? Since it has expanded mapping for an F/I application.

 

@RocketTaco808, you listed that you replaced the MAF. For the sake of the forum, can you post a photo of it showing part number? I just want to be absolutely sure that the OEM MAF is the proper one for your truck. I ask this because just recently I have come across people with OEM MAF sensors but not the proper OEM MAF.

 

Have not reflashed to the TRD one. Would be nice to have, but haven’t wanted to scare J away with too many requests.

figured maybe baseline first to get a proof of concept and go from there.

regarding MAF, let me grab a couple pics.

 

I am half to the point where I feel you purchasing a used ECU, shipping it to J and having him flash it for the TRD map, then with whatever tune your truck has. Then swap it in and see how it goes.

 

Damn, lost my typed message.

have a spare ECU NIB from toyota matching p/n of ECU in my truck, which matches the p/n from the ECU p/n post I typed out (with valued help from folks in TW that seconded my ecu being the correct p/n). J knows, and we’re saving as a nuclear option. Not a bad idea to send over now for the mongoose treatment.

here are the pics. MAF installed is what J and I have been running with. Other MAF is what we were trying to run with (no difference seen in output results from the swap). Both were NIB from toyota.

Please lmk if they’re not the right ones!

 

Well, not being told to lynch my MAF for being the incorrect one, so assuming that’s the right one

going to try one last injector variable change via HP tuners, and if we don’t see live and working fuel trims (not simply -21.1, -23.3 and -3.1 ONLY for STFT and 0 ONLY for LTFT through a lengthy easygoing drive), we’re deeming this as an ECU issue IF replacement ECU of same part number resolves.

Possibly the first legit (non water damage/person/rodent induced) ECU issue I’ve seen on this forum for 2nd gen 1GRFE.. Possibly.

 

Ok, well, my ECU was the culprit for my performance woes. I don’t think this is a mainstream issue for many, BUT, if you wind up with the surging/cutoff issues I had, and you’ve properly diagnosed/tested the normal culprits (vacuum leaks, dirty as f*** air filter, fuel pressure, new/proper plugs, ignition coil/misfire dtc’s, exhaust manifolds properly fastened to heads - they do have a tendency to loosen up when they shouldn’t-, Dirty/busted MAF sensor, OCV Sticking/clogged OCV filter issues, Timing validation, clogged fuel injectors, bad fuel pump relay, other DTC’s, clogged fuel return line, improperly connected fpr valve)… it might be time to try a different ecu. I setup a link showing proper ecu part numbers (though recommend you do your own research before buying)..

my ecu seemed to work ok without major red flag issues, but if fueling parameters were adjusted (via hptuners) to account for larger injectors (as required for supercharged applications) the fuel trim control system went bonkers…. It would only read -21.3, -23.1 or upon total deceleration -3 in STFT CONSISTENTLY. No in between values, no variance beyond stated constants, and NO LTFT!!!

new ecu (which happens to have the trd flash) has functioning fuel trims with actual variance and both STFT and LTFT values reflect real world conditions - not arbitrarily ecu chosen constants.

 

Thank you for the follow-up! Glad you were able to get it sorted.

 

2nd gen, can be fully reset by jumping two pins to each other on the obd port. I forget which two pins, but Google search will bring up a full reset with Christmas lights on the dash.

 

Btw, extreme thanks for helping elevate (or trying) us wet behind the ears folks when it comes to mechanical skills and getting our ponies running right man..