83 MGM starting problem

[Mainemantom]

I have had problems with my 83 MGM. It starts when it feels like it. It has been to three shops. They have just thrown parts at it.
I think it is in the electrical harness. Today It started right up and ran great. I took it out for a good drive. Returned home and put it back in the garage. Turned it off, then restarted it. Turned it off then tried to restart again and it would not start. My plan is to attach a remote starter switch, crank it over and move wires until it starts. Then I will know what connection is bad.
The car has the 302 with the TBI. What other parts could make it do what it is doing ? It is not going to another shop to pay someone for their "time" but not fix the problem.
It is at the point of wanting to sell it however if it will not start all the time, I can't get what I need for it. Any help is appreciated.

[pantera77]

Honestly, I can't say I blame the shops for throwing parts at it. EEC III is downright terrible.

I'm assuming it still cranks when it doesn't start. Next thing to check is to make sure it has spark, if it does you can at least rule out the ignition system.

[slack]

I agree with pantera. Check for fuel, spark & compression.

If it doesn't turn over you can try bypassing the starter solnoid with the key in the run position and big screwdriver on the terminals. I did that when mine was on the fritz. Also another side note, my Deville used to have an issue where after running for a while, the starter would seize up from the engine heat and won't crank again until it cooled back down. Once I swapped out the bad starter, the problem went away. This probably isn't the case but I'm just throwing out ideas.

[gadget73]

yep, fuel or fire. If its got no spark, check/clean the connection to the crank sensor to see if that fixes it. Most people don't know its got one, and it will not give you spark or fuel delivery without any signal from that. Sensor lives on the passenger side, basically hidden next to the smog pump. Should be a 2 wire connector that runs down to it. I want to say the actual plug is hanging out somewhere right near the AC compressor, not at the sensor itself. Either way it should be the only wire running down to that area.