I'm trying to chase down an intermittent no hot start issue. I'm aware of what the ECT sensor does and how it works. The car will randomly no start, but usually only when hot. The car has sat for as long as 3-4 hours and has not started.

My question is....will a bad ECT sensor trip a check engine light? My CEL isn't on so that's why I'm somewhat stumped. If there is no light, should I bother to try to check the connector and jump it?

The last question leads me to a few other questions. The car is a 93 Accord LX. I got to the ECU (in hopes of possibly reading any codes). The ECU is stamped JULY 19, 1993. However, there are NO LED's on the casing anywhere (indicating possibly a 94 ECU??). That has me curious. Also, not sure which connector is the one for checking codes. Looking under the dash, there is a white connector on a mounting tab, that has 6 wires (all black). What's that for? Looking everywhere online, it says the service connector should be blue. Not a blue connector to be found under there. Found 3 connectors together, 2 brown, 1 beige I believe. Service connector have 2 wires?

 

The connector you are looking for is under the passenger's side of the dash, it is blue, and has only two wires going to it.

The location is behind the kick panel. I think that the tegger site referenced at the top of the gen tech help has a diagram showing the location. Short that connector with a piece of wire and count the check engine light flashes. I don't know when Honda made the switch from the LED to the flashing CEL.

A bad ECT should cause the check engine light to come on and set a code.

Is the starter turning the engine? Hot weather + no start sounds like a possible main fuel relay problem. Search this site, that subject has been covered a lot.

 

I think by 93 the Accord was already into the method of flashing CEL.

Tell us whether the starter cranks the engine. If it DOES, then it sounds like the main relay.

 

Not to make anyone sound bad, but I looked EVERYWHERE in that kick panel area and there isn't a single blue connector to be found. It seems like every single thing that I'm looking for on this car, isn't there. No blue service connector, no LED's on the ECU. I've DL'd one of the manuals that gave me the location and wire color. I'll pull the kick panel apart again later tonight and see if the wire colors match what the manual says.

As for the starter turning the engine over during the no-start condition, it definitely does. I got the car to replicate the problem last night (this is gf's car. She is always driving it when the problem occurs.) I let the car run for a bit, get up to temp, then shut it down. Tried to start it back up, it sputtered for a second, died, then wouldn't start back up. Let the car sit for 15 min, and it fired right back up. No CEL's or anything.

I'll do some searching on that main fuel relay problem on here. Keep the ideas coming. Thx.

 

The thing about the main relay, is it doesn't energize the fuel pump. Easiest thing is to listen for the pump, so get into the following habit...

All noisy stuff OFF - radio, ventilation, etc.
Turn the key to ON but don't immediately turn to START.
Listen for the relay, & the pump running for 2 seconds before it stops.

When the main relay fails, it usually will still click, but the pump doesn't run. This normally happens when the interior is hot, like a sunny summer day. Open the windows while you wait for help, then the interior cools down, car starts, & the mechanic thinks you're imagining things.

Know how to solder electrical stuff? Find the relay by following the sound (near driver's left knee). You could pop open the case & re-melt some cracked solder joints on the circuit board.