So here's the issue with my 92 RS, 305TBI...I was driving down the road when all of a sudden the car starts to bog down like the fuel flow is being interrupted, or the car is losing spark? The problem goes away, then returns, it's not constant. At the same time the tach is jumping all over the place.
The first time this happened I figured the fuel filter was clogged, so I changed it, problem went away for a couple of days, then returned again. I then started checking plugs, wires, etc. Changed out the ign coil, problem went away, then returned again. Yesterday when the problem started, the tach and speedometer went haywire and the check engine light was flickering like it was doing morse code. I checked the trouble codes when I got home and nothing but 12 showed?! Here's a list of what I changed/did, please help!

Changed; fuel filter, idle air control valve and connector, plugs and wires, ignition coil.

The thing that makes me think it may be an ECM problem is the check eng light going crazy.
Please let me know if anyone has experienced this, or know what the problem might be.

Thanks,
Marcus

 

What was the tempature out side that day? not your cars temp.
How long were you driving before this problem accured?
I'm thinking you may be having an issue with fuel pressure in your tank.
As maybe not enough as there is supposed to be to help the fuel pump.

 

It was in the mid-80's. The problem usually gets bad when I drive home, not when I leave in the morning. In the afternoon it's worse.

 

It sounds to me like you are having a vapor issue.
I would do a few checks Like a pressure on the fuel tank, as there is not to be a pressure drop there. Like when they do it for emmisions testing. You could have a bad gas cap or it could be your purge valve in your vapor recovery systerm. And along those lines you may want to check the charcoal canister. THe purge valve is a simple vacuum test. It should hold a vacuum. if it doesn't then it is faulty. And when it goes bad it is open.

 

Thanks, I would have never thought of that. I will check it and get back to you.