Ecu issue

[RubyRanger16]

Been having this weird issue with my 94 explorer I did the manual swap and put a manual ecu in it from rock auto it ran perfect for about a week then it threw a 335 code and have a super high idle of about 1500 but when you push the clutch in check engine light goes out and idle comes down perfectly but then the second you release it idle goes back up and light comes back on, warrantied the ecu got another one again truck ran perfectly for 3 weeks not a single issues but on the weekend was letting the girlfriend practice manual driving and she stalled it, check engine light came on 335 code again high idle for a longer then would come down to 600 but is hunting up and down and again when you push the clutch in check engine light goes out and idle goes perfectly, I limped the truck an hour home had zero power was max 60km/h down the highway then randomly I would get full power back and be able to get up to 80km/h then lose it I was able to keep power for about 30 mins every time you stopped at light would lose power again, I took apart the ecu and it look like there a burnt spot I just have no idea if this is just 2 shitty ecu’s or something truck side frying it. Looking for people ideas what to check or test

I did some back probing at ecu
Dpfe on truck when had issue 8v at idle
Spare Dpfe 1 5.30v idle
Spare Dpfe 2 5.20v idle
All 3 drop close to zero when clutch pedal engaged,

I tested a bunch more circuits that could be connected but most seemed alright

 

[franklin2]

What did you do about pin 30? You will notice in the diagram below the vehicle is wired different if you have a automatic or manual on ECU pin 30. You should have a clutch pedal switch hooked to pin 30. "F" comes from pin 46. Would the problem go away if you jumped pin 46 to pin 30?

 

[Dilligaf1]

My book is a 91, so you might have some differences in your 94 but the computer pinout should be the same. So that would be pin 46 that is burned away or actually the trace to pin 46. It's labeled as signal return and is suppose to be grounded in the computer. It goes to lots of places, like

CIS(Clutch Interlock Switch)
Self-Test Connector
BP(Barometric Pressure) sensor
OCT ADJ(Octane Adjust)
ACT(Air Charge Temp) sensor
TP(Throttle Position) sensor
ECT(Engine Coolant Temp) sensor
and my personal favorite
HEGO(Heated Exhaust Gas Oxygen) sensor

My best guess would be some sensor failed internally and is putting enough amps through that pin to cook away that trace, you know like maybe the heater of a HEGO grounding through pin 46? Might also want to check the wires and ground of that/those HEGO. Who knows I could be completely off base, but good luck at any rate.

 

[RubyRanger16]

My book is a 91, so you might have some differences in your 94 but the computer pinout should be the same. So that would be pin 46 that is burned away or actually the trace to pin 46. It's labeled as signal return and is suppose to be grounded in the computer. It goes to lots of places, like

CIS(Clutch Interlock Switch)
Self-Test Connector
BP(Barometric Pressure) sensor
OCT ADJ(Octane Adjust)
ACT(Air Charge Temp) sensor
TP(Throttle Position) sensor
ECT(Engine Coolant Temp) sensor
and my personal favorite
HEGO(Heated Exhaust Gas Oxygen) sensor

My best guess would be some sensor failed internally and is putting enough amps through that pin to cook away that trace, you know like maybe the heater of a HEGO grounding through pin 46? Might also want to check the wires and ground of that/those HEGO. Who knows I could be completely off base, but good luck at any rate.

I went through and continuity tested that burnt ecu and it came back to the TP pin but after checking everything something is still oof with my reverence volt it’s all above 5v but it’s weird with the octane adjusting bar unplugged my ref volt drops down to 4.5v now but it’s constant 4.5v KOEO which is annoying I’m gonna get the ecu fixed that do further testing I can’t test anymore without getting it fixed, I’ll have every sensor unplugged when the new ecu goes in then plug one at a time and test until I find the shorted or messed up sensor