Chrundle

This again... code 52...

95 3.0 sr5 4runner, First post so go easy.

This truck is new to me so I have no baseline but it's not my first 3.0, not even my second. Bought truck cheap due to a misfire, burnt valves. It had codes but I never bothered to check them, fixed the heads, re used knock sensor out of a parts truck with a bad lower end that had no cel, built a new harness from the same shielding wire as Toyota uses, by same I mean it came from a parts truck harness. Dismantemed several short pigtails and made sure they were identical. I know that's not right but with the covid crisis I had nothing but time, and no real urge to spend money. Re used connectors either end but the were clean and not brittle. Everything soldered, and shrink wrapped well. Wire had good continuity and I added an extra lay of shielding with some cannibalized coax, shields crimped and soldered to another length of good factory wire, folded back and sealed as the factory ones are.

watched a video of a guy testing a knock sensor with a meter on ac voltage on the bench, no specific voltage was given but I can confirm that the sensor I used makes a signal, and if I hammer on the bench with the sensor firmly placed on the bench I could see the signal raise, then fall. I had 2 more 3.0 knock sensor in my hoard of parts, 2 tested identical one had no raise in signal when striking the bench. Figured my sensor and homemade harness are good. Even tested all said sensors with good, but let's say suspicious factory pigtail, same reading on my meter.

went ahead with installing, obviously code re appears after a rev or two, engine idles worse. In all my time with these motors and pickups I have never had a code 52 problem, and changing the parts again dont necessarily scare me but I cant convince myself it's the problem. With the engine running performing the same ac volt test I see a voltage that stays realitvly consistent at idle and increases with rpm, that's seems to be functioning. Dont quote me on the numbers exactly as I have already forgotten, and if there is a right range I should be seeing please let me know, assuming this test isnt junk... cant trust everything you read.

I am to the point of checking the wire between the sensor pigtail and ecu. Other then checking ohms on the signal are there any other helpful tips? Iv read atleast 20 pages on this so dont think I havnt tried to do some leg work. How many people find it to be the engine harness? I know people say the knock sensors dont go bad, already found that to be untrue... ecm swapped, so theres that... Kinda boils down to wires like always, but I dont think they are the ones I built doing it.

it has had a early pickup 3.0 swapped in, factory 95 ecm, 95 harness. Plugs swapped on the few that dont convert over, like knock sensor and yes the are re pinned correctly. I cant believe this is the issue either because I have another one that is exactly opposite 90 pu, 95 4unner motor. Not a single hiccup until the head gaskets gave but that's hear nor there.

timing is correct, tps in range, i think, and if not does that ever really cause this code? ... ecm swapped with matching numbered unit that proved itself to work, or atleast it came out of a cel free vehicle.

could it be a bad engine ground? they appear to be installed correctly and clean. Should I find the shield at the ecm and ground it directly? Has anyone actually relocated one successfully? I am too OCD for any hacky fixes but I have another knock sensor and all the used parts anyone could ever want to try and pinpoint this pesk. Am I Insane for keep buying 3.0ls?

Any help is appreciated.