Kzj78 Ecu damaged, symptoms and diagnosis (1 Viewer)

[VannCruiser]

Hello

Haven't posted in a while.

Truck: 1995 kzj78 1kz-te M/T
Kzj78w-Met

Fuel level light went on, uh oh, I turned around and parked the rig, went to get fuel with car.

It started snowing so I waited until next morning. I parked close to my boat so I wanted to move my truck up a few feet.

Started normal, few cranks, then died. Repeat. Now no start. I quickly filled up the prado, primed no start. Strange. Push into garage to let warm up, fear of some ice or water in lines. Change filter, prime. Fires up, died. Ok now I'm noticing no fuel to injectors but fuel to pump. Test all sensor/valves, all correct ohms etc. Crack injectors and bleed, closing one by one. Clean spv filter and fuel temp filter, Fires up a few times but dies. Voltage to Spill control is low... barly 2volts. Give 12v power to spv, click click, fire up truck but dies. Trace wiring, all good.

Open my ecu. Oh no. Some nasty stuff. Truck has 87,000km

Now to find an ecu repair in canada, manitoba lol.

 

[Shyrock]

Not Canadian, but they offer ECU repairs:
Services | Relentless Motorsports TX - https://www.relentlessmotorsportstx.com/services

 

[VannCruiser]

Not Canadian, but they offer ECU repairs:
Services | Relentless Motorsports TX - https://www.relentlessmotorsportstx.com/services

I will give them a call

 

[VannCruiser]

Can anyone give me the info on c002 it's bottom right corner in my pic, it's a fuse and it's black right now.

 

[Combat Wombat]

Ive repaired heaps of these, it can sometimes be a full day running new jumper connections and removing the old components without delaminating the PCB...
Or it can take an hour and works perfectly.
Havent seent it as much in the manual ECUs though, more common in the Autos (the transmission control section normally)

 

[VannCruiser]

I'm trying to find the dioide I'm supposed to replace. The black blue with a L

 

[VannCruiser]

Fixed now!

 

[VannCruiser]

Thank you @Tigris .

After all this it was relatively easy to fix. Had to do some work on the copper lines, replace some caps, and actually the diode was in good working function, just coveted in the cap oil. If anyone is canada needs help, or work done on these message me.

 

[Triplefat]

Having a similar no start issue with my 1995 Prado automatic. Noticed no fuel at injectors but fuel to the filter. Then I noticed my CEL and glow plug lights aren’t coming (I do hear the click though). So I pulled my ECU but to be honest my ECU looks great to me, so I’m a little lost. I do see maybe one little black spot next to C003, trying to figure out what that does.

 

[Combat Wombat]

Do you have access to someone else with a similar/same vehicle model that you can temporarily swap in their ECU to see if it solves anything?
One of the hardest things Ive done is repaired an ECU, charged the time it took and it STILL didnt fix the issue.
The glow plug system has a relay, and the power supply that triggers that relay may need verifying/testing first.

 

[Triplefat]

Do you have access to someone else with a similar/same vehicle model that you can temporarily swap in their ECU to see if it solves anything?
One of the hardest things Ive done is repaired an ECU, charged the time it took and it STILL didnt fix the issue.
The glow plug system has a relay, and the power supply that triggers that relay may need verifying/testing first.

Unfortunately no I’m in Connecticut so not to many 70 series out here. My CEL and glow plug light were working when this problem started which is the other odd thing. But now two months of sitting later stopped working. I’ll look into the glow plug power supply

 

[Triplefat]

Does anyone have a diagram of what each circuit does on the ECU? I’m curious about C003

 

[VannCruiser]

The shop fixed it, the old polish guy just knew ehqt to swap in.

 

[Triplefat]

Yeah I found a computer guy out here to change all the capacitors, he also found a trace that was bad. Working like a charm now.

 

[LDRF]

The shop fixed it, the old polish guy just knew ehqt to swap in.

Someone local to Winnipeg?

 

[VannCruiser]

Someone local to Winnipeg?

Yes