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]

So I did a little bit of poking under the hood today, and this is what I've found:

Pulled off the cap and rotor, found that there was a bit of oil at the bottom of the cap. It seems that where the distributor assembly mounts on the motor is where the leak is. There's a few hoses as well as a harness directly below the dizzy with significant amounts of old, built up oil, and it seems to be a little cleaner near the dizzy mount. Its hard to get an eye in there, so i was mostly checking the condition of the oil by feel. See photos:

Bottom of cap:


And here's the hose/line below the dizzy, the harness/wiring is farther below that. I don't think this would be the source of the leak, as this looks to a be a coolant/water line to me. If you look just above that, the dizzy mounting bolt is wet with oil.


I don't think this oil could cause the problem, as its not interfering with the electrical connections, however its concerning. Would this simply need a gasket/o ring to be replaced? Or would this require entire dizzy replacement?

This next photo is the inside of the cap. Looks like there's a slight bit of corrosion on the contacts. I'm not sure if this is something that can be cleaned, or if that would require replacing. Or if thats even how it should look, its been a while since i've seen a fresh cap.


Rotor:


Dizzy with dust cap removed:



While I was in there I checked the resistance of the Ignition Coil, based on the link Box provided, and everything seemed to be in spec. The next time this issue arises i'd also like to check by removing a plug and checking for spark, however being intermittent, I need to wait for it to come up again.

I also checked the Resistance of the IACV, and that also seemed to be withing spec (19 - 23 ohms, based on this link: http://www.toyotanation.com/forum/103-camr...eaning-iac.html which is a great article on how to remove and clean the IACV). So that can rule out a damaged/malfunctioning IACV I would think.

I also checked the Igniter wiring for cracks, and there was no signs. All of the wires seemed intact. I tried to trace this back to where it would ground as Batman mentioned, however it leads back the main harness, at which point I lose it. Is there a way to test this with a multimeter?

Next was checking the resistance of the coolant temp sensor, however, when I went to do this, my sensors were slightly different than the image box posted:



Based on the image posted by Box, I would assume the sensor on the right side (Lighter grey) would be the coolant temp sensor, but this sensor only had one wire leading to it, and one terminal on the inside of the plug which I found odd. So I wasn't sure if this was the correct sensor, or how to go about checking its resistance. I couldn't really do much else with this.


After this was all done, I drove to the parts store, and picked up some injector cleaner (long shot) as well as some Seafoam deep creep to clean out the IACV while its still on the car. I thought this would be worth a shot. I drove it there, and the car was at operating temp, came out and it stated up fine, drove to the gas station filled up, and it started fine once again and then I drove home. I feel like this issue is going to be a pain to resolve due to being so inconsistent.

I sprayed down the IACV and also ran fuel injector cleaner in the gas, but I'm not convinced this will resolve anything. I've also removed the short ram intake, and put the stock air box back it, but I doubt this will have any affect on it either.

As this is an intermittent issue, Ill try and keep this thread update as frequently as possible, but it may go some time without posts, depending when the issue arises.