Intermittent stalling on warm starts, No issues with cold starts. Options

[jordisonjr]

Hey guys, looking for some advice on an issue that arose on my car. Ill start off by saying its a 95 GTS (Canadian car) with a 5sfe. Motor is completely stock aside from a short ram intake, which I've just replaced with the factory air box.

From time to time, when the car is warm, it'll give a tough time starting. Ill start the car up cold and it gives no issues, drive it untill its up to temperature, and then turn the car off. I'll let it sit for 10-20 minutes, come back and the car will give difficulty starting.

It'll fire up to about 1000 RPM (regular idle) and then drop right back down to 0. If i give it some throttle I can get it to run if i hold the RPM at idle for 30 seconds or so, and then it runs and drives fine. However if I don't give it throttle it just stalls out again. This problem is also very inconsistent, majority of the time it will start and run fine, but when it does give me problems, its always under these circumstances.

It occurred once this week where i had to give it a significant amount of throttle(1/4 to 1/2) to force it to start, and then held it at idle for 30 seconds or s, and then it idled fine.

I posted this on the facebook page, and also did some researching on other toyota forums, and have a very very rough idea what could be causing this, and I'm hoping someone could provide some insight as to what could cause this. Its a difficult thing to diagnose, as it doesn't happen extremely frequently, but I'm also hesitant to drive it, as I don't want to get stranded somewhere with a vehicle that doesn't start.

Any help or advice would be greatly appreciated.

[jordisonjr]

Thanks everyone for the replies!

How does the distributor look? My guess is cap or rotor.

Distributor, was replaced a few years ago with a used one, which I also replaced the cap and rotor on. There's also no CELs being thrown.

Check the coolant temp sensor resistance against the chart in the BGB when it's acting up, sounds to me like an intermittently failing CTS, likely reading very cold when the engine is very hot which causes it to inject WAY too much fuel for starting with closed throttle, opening throttle allows in more air and leans it out enough to start and then when you hold open throttle it clears out the over fueling. Why it doesn't continue to run rich, I'm not sure, but I would be sure to inspect wiring and connectors.

Where is this located? and how would I check this (Sorry, very unfamiliar with electrical things like this) The explanation you provided does make sense to me though.

I would check the ignition coil along with the cap and rotor. IACV and EGR would be next places to check.

Where is the ignition coil located? And how would I go about checking this? What should I look for in the cap and rotor? It was replaced a few years back, but could be due to be changed again. I've read more than a few times that it could be IACV related.

A member on the facebook page also mentioned this could be a bad MAP sensor as he was having similar problems. When this first arose, I was thinking it was more fuel related than electrical/sensor related.