1G 92 Talon Tsi turbo no start condition

[Jthroener]

Been having issues and banging my head on the wall to get this figured out.

Car was running just fine, went out to start one day and got nothing but a crank. Long story short, I am not getting the initial stage of the MPI to activate. No CEL light and boost gauge does not go to 0.

I have checked all that I know of to check, I have power at the computer pins 103, 108, and 110 with Key on. I have a solid chassis ground on 101 and 106 and have even introduced another ground to those at computer. I have power on MPI with key on at 10, 9, and 3 with ground at 6.

For some reason the computer won't ground computer pins 63 and 66. From my understanding, this should go to ground once it sees ignition key on power from the ignition switch which is being shown to computer. When I manually ground it, I will get a quick CEL light flash and no boost gauge movement. Also when manually grounded, I will get the power off of MPI 4 and 5 to the computer but still won't fully power up and still no start.

I have also sent the computer off for rebuild, in which first time it did have capacitor leakage. Since then its been sent off 2 additional times and comes back as nothing wrong. It seems as if I am missing something simple, but can't understand what so looking for any and all advice.

Thanks in advance.

 

[steve]

Sounds like you're following the right steps. Who are you sending your ECU off to for repair?

You shouldn't see 12v on 108 until the key is in the start position. Same for MPI relay pin 9.

Pins 102 and 107 get 12v from the MPI relay when it switches on. Turning the key on to either the accessory or run position should provide 12v to pin 110 and to MPI Relay pin 3. That on a good ECU will cause it to pull pins 63 and 66 to ground, activating the MPI relay but that also requires the ECU at pin 103 to be getting unswitched 12v from the room fuse to provide backup power.

Since you see 12v on MPI pin 10 and when you ground MPI pin 8 the relay outputs 12v to pins 4 and 5. It's working. Have you checked the wiring harness between MPI pin 8 and ECU pins 63 and 66?

 

[Jthroener]

Yes sorry, pins 108 and MPI 9 show 12v only when cranking. The backup power stays at a constant 12V with Key on and even when cranking. Verified this with an actual light bulb also. Computer was sent to Flagship One. I have not pulled apart the whole wiring harness, but I have measured Ohms between 8, 63, and 66 and all measure good continuity.

 

[steve]

I don't know who Flagship One is other than a quick google search but my experience with places that don't specialize in these ECUs is they miss quite a bit and often do a sloppy job repairing them. It takes time to clean up capacitor electrolyte leakage and it's hard to make money that way.

The only people left that I'm confident with is ECMTuning. Hopefully you'll get back a working ECU but based on what you're telling me that's sounds like the problem.

What Make, Model, and Year 1G do you have?

 

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