Anyone ever repaired a K car SMEC controller?

[Moparnocar]

Well, drove about 10 miles, died pulling into gas station. Tryed to restart, and it sputtered.

Went into gas station to build some type of test light to start testing. After 10 minutes, tried again and it started.

I had my relay on to bypass the ASD circuit, applying ground to the fuel pump relay ( it grounds the blue/yellow wire, powering fuel pump and coil etc) because that is what I found not working last time

I am gonna replace the dist sensor, I haven't yet. I ran it for a hour, and it didn't die. I also wiggled every harness

I know it could be anything, but any other ideas on what to stress/look at?

If it died again, obviously be easier to fig out. Fuel. Pump is new also. I had fuelsquirt out of test port when it died this time, so I'm assuming the pump was running, but I had no real tools with me

 

[Moparnocar]

Well, I pulled apart my SMECbesides cracked epoxy, it looks like a chip my be partially melted, I'm not sure what do the experts say? Besides get a new car .. lol

 

[Moparnocar]

Better pic

 

[Billccm]

inspect for fractured solder joints on the molex pins.

 

[Demonic]

inspect for fractured solder joints on the molex pins.

This ^ And all the grounds. You need a digital voltmeter with adapters to check current draw. Older components draw more amps, which equals heat, which leads to the SMEC looking like it does. Do a current draw test on all loads connected to the SMEC.

 

[Moparnocar]

This ^ And all the grounds. You need a digital voltmeter with adapters to check current draw. Older components draw more amps, which equals heat, which leads to the SMEC looking like it does. Do a current draw test on all loads connected to the SMEC.

So that chip IS burnt up? Hard for me to tell, but there is holes in the silicone material

Are the molex connection the big gray one I'm looking at? I don't know how I'd see the solder without removing all the epoxy

 

[Moparnocar]

Got a supposed good SMEC from a 89 lebaron turbo. Eprom # matches that. My old eprom says V6... Night had been reprogramed?

You can see, that area is not damaged on the new one. Any idea what component that controls? Also, how do you check these molex pins?? Do you have to remove the epoxy ?

 

[Moparnocar]

Well, after 10 miles, 2 trips, it died in my driveway at idle, same as last time it died, this time, I was prepared

I hate incomplete internet sagas, so here we go

No fuel pressure. Had power to coil/injectors. ASD/fuel pump relay tested ok

Went back to fuel pump, the second I touched the connection, it turned on. When I let go, it turned off. Connector looks perfect. So hard to believe that's been causing my problem, bit it looks like it. It's a weird one, so I'm going to have to make one probably

 

[Moparnocar]

Here's a pic of what the pins look like, it's a weird triangle shaped plug. Haven't been able to find one aftermarket, this plug configuration look like anything else to any one? The 3 pins on the left, only 2 are used

 

[Moparnocar]

Saga continues....soldered wires on pump, pump runs, still no start..

Swapped out new dist sensor no change
Disconnected map no change

Used noid light, seems very dim, barely can see it, but it is working, on at least 1 injector

Used same light to check coil firing signal on - coil, nice bright and blinking

Did these have injectors short out, and draw down voltage like the old 2.8/3.1 GMs?

I'm ohming them next

Has code 42, but that maybe cause I am grounding ASD on key up. I have since disconnected it

 

[Moparnocar]

Well, I lost the ground from the SMEC to to ASD/fuel pump relay again, even with used SMEC

I checked power and grounds to smec. Everything is there, except 12v key up power from fuseable link. I replaced the wire, now I've got everything. Also, 8v reference voltage to logic board is actually 8.7v, don't know if that matters

On key up, blue/yellow wire should turn on ASD for 1-2 seconds to run fuel pump. It does not do this anymore. Grounding this wire, allows the car to run

What am I missing, that the SMEC won't activate the ASD for 1-2 seconds on key up? I believe I have all input to do that

Still don't know how to identify these molex pins another poster is talking about