In a 88 honda civic when it is hot outside the wether wont star when is not so hot star with no problem?

we need a little more info than that. hot/cold mornings, smells, sounds, etc.

Start with the battery unless fairly new & have that tested

Next turn key on & listen for fuel pump

It may run but not have pressure or volume

Check fuel pressure at motor with a gauge

Any light on dash & you checked for codes
didn't you? What are they?

Turning over & Starting are two different things,
don't use them together,different systems there

My first guess would be the fuel pump relay or the ignition module.
Look for something that gets hot and fails like a relay or electrical part.
When it won't start, check for spark at the plugs and the fuel pressure.

You may need a new O2 Sensor, but that isn't
why it won't start.

Don't throw parts at it

Have a local repair shop ,at least check it out
for you

its more than likely the alternator drive belt needs re tensioning if its got aircon that belt may cause the same problem just get the drive belts checked and re tensioned

Have seen this MANY times in Hondas but am not there to be 100 percent sure but you are describing ot exactly what I have seen in the past. The first one I worked on that this happened to took me almost 3 weeks to figure it out. The thing that I have found like I said MANY times ended up being the PGMFI relay which when it gets hot does not work. Below is a diagram of it's location for you. Now I'm pretty sure you don't have the high dollar computer diagnostic equipment on hand but what you can do is when the vehicle does not start spray (just a mist do NOT soak as it will short out everything) some cool water on the relay to cool it down. If the vehicle starts after that, chances are, that's your problem. Again I am not there and cannot be 100 percent sure and would hate for you to spend money for nothing but have seen it so much and so common, this is the first place I always go with this symptom in a Honda for that year. If you have any questions, feel free to email me at [email protected] and I will be happy to answer any questions if I have the information you need and there would be no cost, don't mind helping. I hope this helps and good luck.

check ignitor unit inside dist. and coil.

more than likely your vehicle speed sensor is bad try replacing it

I have same problem . i wonder if it is the fuel pump. please let me know if you find out.