Need help with ecu electrical issue

[Tjpinkston]

Short version of status: 92ls donor swap Ito a 68 f100 with crown vic ifs. Pulled motor and put new plugs wires caps rotors etc. motor ran ok in car but was a little rough. Alternator was not putting out due to leaking so pump. All new now and have 14.3@idle. Pulled and meticulously labeled complete harness from car. Wired up in truck and runs and drives ok. Running rich (9-10mpg ) and I have no power to cel and diag connector. Dash coolant sensor and speedo not functioning. Both worked in car. I have checked and set tps, iacv functional, maf checked good. I did an egr delete and resistor is wired in. No cats and secondary o2 not hooked up. I also bought another ecu and symptoms are the same. Caps look good. All fuses good. Cel functioned in car. Only code was cam sensor, found broken wire and repaired while engine was on stand. Please advise on what to check.

 

[George_R]

running rich without 2nd 02 sensors / emulators is pretty normal
diag. connector's '+B' pin shares power with MAF, VSV's, and 02 sensors. It's fed from master relay output.
warning light in the dash takes positive power from ignition barrel, and negative control signal from ECU pin W

 

[Tjpinkston]

Maf has +5vdc. I will test B terminal and update. I was under the impression that it would just throw a code without the secondary 02s. They're just for there for converter function check and the primary's did all the closed loop calc. Thanks or the response.

 

[George_R]

sorry I forgot that on early 1uz's maf does receive +5v power, anyway check for +12v at +b terminal

when ecu can't monitor cats it enters failsafe i.e. goes rich

 

[Tjpinkston]

Checked all pins on diag connector under dashkey on motor off; motor running)
Ab 0.7 ; 0.95vdc
A/c 0 ; 0v
A/d 0 ; 0v
ECT 0.46 ; 0.46v
W 0.6;0.6v (ofl continuity to earth)
Eng 0.05; 0.05v
Tt 0.01;0.01
Tc 10.35; 13.39v
E1 0; -0.01
Te2 4.98; 4.98v
Te1 4.98;4.98v

 

[Tjpinkston]

Is there a quick way to make sims for rear o2s to test? I have the sensors and the cats but don't want to pull the exhaust and weld in unless I have too. I have read you can wire them in to the primary's (parallel).

 

[Tjpinkston]

Got to do a little more checking before work tonight. Cel has 12v+ to it from key. If I jump other side to ground it illuminates. Ofl to ground on red-blue wire. Should have a little more time tomorrow afternoon to trace all the way back to ecu. Planning on wiring secondary o2 signal wires together with primary to see if this corrects rich issue. I'm thinking it is in limp mode for some reason. Hoping to get cel working to narrow this down further. I am also planning on ohming out ecu coolant temp sensor to eliminate that also. Just FYI Per Toyota specs it's approx 16.2kohm @ -4*f, 2.45kohm @ 68*f, and 0.32kohm @176*f.

 

[George_R]

See my posts above for the explanation regarding the warning light wiring. the negative side is most likely disconnected from ecu due to your fault to wire it properly.

don't know about early 1uz's, however with vvti engines, cats fault is detected if sub sensor signal copies that of the upper one....that's done per each bank. You should also simulate heater circuits. When you get to heater circuit simulation, you should also check if the heaters have power. The +B terminal I mentioned earlier, it's located in engine bay diagnostic connector

 

[Tjpinkston]

Wiring has not changed pulled 100% of oem harness from car. Plan is to get everything up and running before thinning out unneeded circuits. Sub o2 do not run heaters only primary's. I will report back this evening on b terminal +v. I should have a couple hrs to troubleshoot before work.

 

[Tjpinkston]

+b 12.41vdc key on, 14.14v running

Ecu coolant temp sensor 1.47kohm at 65*; 0.52kohm after ~10 mins idle (good)

I will get cel earth traced back to ecu tomorrow.

 

[Tjpinkston]

Found 21 pin connector not hooked up. Was in same area as heater harness. Everything working now!