Hard (Re)Starting Hot, Not Temp Sensor

[SephirXV]

Standard hard start when engine is hot (cab temp doesn't seem to matter), normally we blame the Main Relay.

But... I recently was getting an ECU code 6, discovered one of the wires had broken out of the plug and had to get a new one from the yard, thought that fixed it, but no. Without the sensor, it was hard to start, but it would start within 10 seconds. Now that the sensor is fixed, the car absolutely won't start hot, I have to pop hood, pull plug, start, and ride it home with CEL on.

Could be main relay, having resoldered yet, but I don't think so, because when it's trying to start I can smell gas after it's cranked for awhile. I also thought that maybe timing was off at dizzy, but when I checked it a few weeks ago, it was dead-on at warm idle. I didn't check it's advance/retard at various throttles, could that be it?

The main relay is supposed to power the fuel pump, so why doesn't fuel cut out when the engine bay or the interior get hot, why does it only affect starting?

[moonjaw2002]

Had the same problem with hard start hot.It turned out to be a leaky injector filling no.3 cyl with gas.
The o2 sensor will cause a hard start,it tells the ecu what gas mixture should be.
Check coil also to see if breaking down at high temp.Mark

[greentee76]

Did you replace the sensor or just fix the plug?

[2oodoor]

replace that sensor with the batt disconnected?
assuume the ecu reset
o2 sensor causing hot start problems seems out of hierarchial order, everything else makes sense though
starts right up first hit once you unplug the same sensor? hrmmm two wire o2 sensor, what kind of car is this again?

[2oodoor]

ECT is code 6, sure it isnt flashing two sets of code 3 MAP

edit, Im sorry I got mixed up.
leaking injectors sounds logical, but not when you unplugg the JY ECT sensor it starts.
O2 sensor causing a hard start would give you an ozone smell a few seconds before it finally turns over, it would be reading rich and cut down the fuel or injector pulse. Seldom see it the other way around.
any other symptoms at all?

[LX-incredible]

An o2 sensor doesn't come into play while starting. Replace the TW sensor. I had the EXACT same issue.

[Demon1024]

same here with the tw sensor, but check your air filter before you buy one it can cause the same problems

[2oodoor]

An o2 sensor doesn't come into play while starting. Replace the TW sensor. I had the EXACT same issue.

technically true, but is can send a code as a result of the original problem that is why you use codes as only one piece of the diagnostic puzzle.
I am not sure if this ecu has clear flood processing from an 02 reading or not, actually I doubt it

[w261w261]

I barely made it to the Honda dealer to pick up my new TW sensor, and had to install it in the dealer's parking lot (the dealer had to order it, so I was sweating it out coming in....in the final stage of he sensor's decline, it got noticeably harder to start when hot each time I tried). I don't think it would have started hot one more time...that's how bad it got. 6 flashes on the ECU. So I'd vote for the TW sensor too.

[AZmike]

Replace the TW sensor. I had the EXACT same issue.

Same here. It would start and run poorly and eventually got to the point that it would not start hot.

[nsstech]

Mine used to have this problem. It's an 88 LXi with 387,000 miles. I used to have to crank it for about a minute straight and the battery would sometimes almost get weak enough to not even crank the motor. Replaced and rewired the coolant temperature sensor, 25$ at autozone. This got the hot starting problem down to about 30 seconds. I could always smell gas when trying to start though, so I figured the main relay was fine. 2 months down the road I said fuck it and bought a new one for 60$. I didn't want to resolder, I figured it would be best to replace the whole unit as it had been exposed to possible water damage. Got home, removed the old relay, and installed the new one. Car cranks right up now, I have yet to have a problem for 3+ months. Give it a go :cheers:

[Dr_Snooz]

Try driving it for awhile. The ECU may just need time to reacclimate to getting a signal from the TW sensor. If you haven't already, reset the ECU by pulling your #11 (Clock) fuse for 10 seconds. Then drive it for a week or two.

If you continue to have problems, take a hard look at your Main Relay again. Re-soldering will not always fix it. Sometimes the relay itself is bad and the entire module needs replacing. Finally, I'm struck that you are getting a gas smell. That sounds like a leaky injector to me. Those are expensive, so replace them as a last resort and only after making sure that they are, in fact, leaking. Obviously, if you continue to get trouble codes on the ECT, you'll need to replace it as well.

I don't think timing has anything to do with what you are describing.

Good luck!