Ok, so my 93 del sol si has been acting weird lately and this issue came out of nowhere...

When I go to start the car, the fuel pump doesn't always prime, it does and it doesn't when it wants to. Eventually it always starts. I have replaced the fuel pump and main relay and even the mechanic I'm going to is stumped...

All grounds are good, all fuses are good. It's been happening for the past 2 weeks everyday.

HELP!!!!!!!

 

Clean and tighten the G101 ground attached to the thermostat housing. If that doesn't help, swap in a known good ECU.

 

If "lately" the weather has been rainy/high humidity and the car sits outside then yes I bet the ECU also. I have a 93 del sol si and had the same problem. I've noticed a lot of 93's experiencing this lately. I think 19 to 20 years is the life of the ECU in humid climates.

 

I was really hoping it wouldn't be the ecu...the mechanic said it may be the factory radio/ALARM acting up? Like it somehow is just now, randomly, cutting off fuel for some reason. He's taking a look at my dash wiring today.

 

The radio and the fuel system are related? On what planet? The fuel pump priming has nothing to do with the radio nor does the radio have anything to do with the ECU.

 

The mechanic was thinking the factory alarm (which is through the factory radio) might have a fuel cutoff feature, which is false. He found a loose connection on my ignition coil, and tightened it. I don't understand how that fixes my fuel issue, but the car hasn't given me problems all day...

ECU could be the problem.

 

You can get a used ECU from a salvage yard for around $100.
You don't need a new ECU from a dealer (big bucks).
Check the label on your ECU to get the exact model # and check around.
If you are already dealing with a mechanic (Honda mechanic ?) ask him if he has a spare ECU laying around just to pop in and try it out.
Find a friend with the same car and ECU and just swap it.
Make a note of your radio code before you detach any ECU's.