[rturner]

I have a 90 Si all stock except for a cold air intake. My problem is when it is hot and humid outside my car will not start. It'll turn over but seems to get no spark. All the plugs, wires, rotor cap, fuel filter have been replaced within a years time. Any ideas? It seems to do it most when it is humid outside.

 

[ludesrv]

Most common issue in our cars. You aren't getting gas, you have all the spark you want. The reason you don't have gas is your main relay doesn't turn out (bad soldering, a new one will fix it, or you can add solder to your existing one). Notice when you hear a click with engine light coming on when you first turn the key, it will start, and when there is no click, it won't? That's the main relay saying 'I'm on' or 'I'm off'. The main relay turns the fuel pump on and off.

 

[tyson]

classic main relay issue.

 

[rturner]

Thanks for the replies. Why does humidity play a factor in it? I've taken out my relay before and everything looked fine. Where do I buy a new one. I really hope this fixes it. Thanks again

 

[ludesrv]

Thanks for the replies. Why does humidity play a factor in it? I've taken out my relay before and everything looked fine. Where do I buy a new one. I really hope this fixes it. Thanks again

Honda, and humidity is moisture, moisture and crappy electronics do not mix at all. Plus that baby gets hot, so it expands and the contacts lose touch to one another.

 

[MX5RACER]

I had a issue just like this before and it turned out to be the coil. There is a test you can do to test the coil, not the method I describe below. I would test the coil and inspect the main relay. Without trouble shooting this more, we cannot give you a better guess than what commonly goes wrong.

Pull off one spark plug wire from any spark plug and put a spark plug in the wire. Then hold the spark plug next to a good ground like the engine. Have someone else turn the car over and check for spark. If you are not getting spark, then it is ignition related. If you are getting spark, check the main relay, just above the hood latch under the dash. Touch the relay and put the key to the ON position. It should click, if it does, turn the key to run. It should click again, sending a message to the pump. If you do not get these clicks, then you have a relay issue.

 

[jfrolang]

I've had spark with a bad coil before.

 

[tyson]

Thanks for the replies. Why does humidity play a factor in it? I've taken out my relay before and everything looked fine. Where do I buy a new one. I really hope this fixes it. Thanks again

its usually a crack in the solder joint. just resolder the connections on the pc board.

 

[rturner]

Thanks guys. I'll try to pinpoint my problem my next day off work.