my 85 12a wont start/stay running
 

i bought a 1985 12a gs a few months ago everything on it is from factory. the guys that had it before me had it running for a little while then sat for a few months. when i got it i got it to fire up but after about 5 minutes but it died. but it fired right back up but this time it wouldnt hold rpms on its own and it sounded worse then the first start ue and i had to keep my foot on the gas. once it died that time it hasnt started on its own since. the carb has been rebuilt and i feel thats my issue cuz it was never retuned and ive been cranking it for months and hasnt flooded yet but timing is also off from what im told and they say thats my issue as to why it wont start. it does fire up and has good compression but i have to use starter fluid and last time i used it to start it it only ran for 5 seconds and it killed its self like there was no fuel. i really need some help cuz im completely stomped as to what it is

You need to verify the gas delivery (right pressure and flow). Also start at the tank and verify that it looks like clean gas and a clear filter are installed. Next make sure the pump is working and putting out the right psi (2.5) and flow is good ( 1/2 gal per second (a guess)). If it sat for any length of time you need to suspect the gas is old and causing issues.

Check the sight glasses on the sides of the carb (front and back relative to the direction of the car). You might need a mirror for the rear one. At idle fuel should be right at halfway. If not that's probably your issue and you should go ahead and check/replace the fuel filter and see if that changes anything. The fuel pump on later years (like the 85) only runs when the engine is spinning, which means that you would have to jump it to get the bowls to fill without the engine running. There are some threads around here on how to test the pump in this way.

Timing should only require one adjustment unless someone has messed with the dizzy. Connect the timing light to the front leading plug (the furthest forward lower plug) and set the timing to where the yellow mark on the main pulley lines up with the pin on the front cover (you'll see what I mean).

I hope that made sense.

So anyway, set the timing correctly and check the fuel bowls/replace the filter before you go much further.


Edit: Dang, I've been out-typed.... :)

the first thing i did when i got it was check the filter and changed the gas. i cleaned the filter with fresh gas to get some of the deposites out. then put some fresh premix in it in case the omp goes out. the pump has been over ridded and its pushing a good flow

we have a over ride on the pump so it turns on when u turn the key. thats how we got it started the first time. i reset the timming on the dizzy a few weeks ago (lining the dimple with the notch). my biggest question is does the car have to be running in order to set the timing cuz im told yes and no

Yes.

When I first got my car running I had someone run the starter, while I used the timing light to verify timing. I don't remember but I may have removed the trailing plugs to reduce compression and increase rpm. You will also need a battery charger to keep the battery from going dead.