gas mileage/electrical?

[AgInternational]

I drove my 91 2 door sport about 30 minutes then shut it off. about an hour later, I started it up and the radio, blinkers(not the emergency flashers), power windows, and fan panel did not work. I drove for about 10 minutes then shut it off. about 2 hours later I started it and everything worked. that was 3 days ago and everything still works.

Now, since then my fuel gauge is dropping a lot faster, thus horrible gas mileage. I don't know if they are related or not. maybe its just a coincident. I'm not sure. Does anyone know why this is happening? anything helps, thanks.

 

[Anime]

My guess would be the ECU. When the capacitors on the ECU motherboard get old, they leak, and can damage the other electrical components, or damage the pathways between them. The most common symptom is a vehicle that won't start even though everything else is fine, but other random electrical issues or strange problems with no explanation that come and go seemingly randomly have also been traced back to a bad ECU.

The solution is to remove the ECU and have the bad caps replaced with new ones, but since most people don't have the caps or soldering skills to do so, they either send it out for a refurbishing, or just buy a used ECU that hopefully lasts a little longer. You can't buy a new one anymore, and even if you could, they'd be hundreds of dollars. The caps themselves are only a few dollars apiece, if that, but the cost is in the equipment to do the job and the skill to do it without damage. You can buy semi-refurb'ed ones at auto parts store or on Rockauto for a hundred or so, and if they don't have yours in stock, they can take yours and refurb it instead. They don't always do a great job, but there aren't many other options unless you know someone who can do precision soldering.

 

[AgInternational]

I also had one time where I turned the key, the dash lights all came on, but when I continued to turn everything went dead. I jumped it and all was well. no problems with that since.

 

[Anime]

You might try just looking up under the dash with a flashlight, and also inspecting the engine compartment wiring as well. Even just replacing the underhood ECU relay with a good one might yield results. It could be a simpler, smaller electrical issue, but the ECU is my guess when it's wierd electrial issues.

 

[Mettler]

Do you have an alarm? check that too.