Time to bring this back again. I thought my problem would be gone for the winter since it used to only die on hot days. Not so now. It is now dying with temps in the low teens.

As an update: I did the telltale light for the power supply to the distributor and it stays on all the time. Even when I am in a no start situation. I did not do the fuel pump because in a no start, I can still hear it run right after turning the key on.

Any new thoughts?

 

Having the fuel pump running, & good pressure at the fuel rail, is important. But it doesnt prove the injectors are firing.

Can you check for reliable power at fuel injectors?

Each injector has one wire of same color as other injectors (yellow/black?). That should have good battery voltage whenever the key is turned on.

The ECU switches the ground side of the circuit. The other wire for each injector (4 different colors) are connected to ground only when the ECU wants to fire that injector.

 

Much as I hate to resurrect this again, my problem persists. Here is an update:

We finally took the car into a shop to see if they could figure something out that I was missing. After 2 hours of diagnostics and driving around, they came up with nothing and I can't afford to have them continue to troubleshoot.

I have had this nagging feeling all along that it is related to the fuel pressure regulator. Messing with it is the only time that I have seen changes. In fact if I pull the vacuum line off I can make it die much more often and in the same manner. So... I purchased a new FPR and put it on. Thought we had the problem fixed. No dying for 3 weeks and then, presto, it dies again. It is dying less often now than it has but it still dying.

So, I need some help on checking voltage to the injectors. I don't know how to do this. Any other ideas would be great also.

 

Easy way is to get/rent/borrow a "NOID" light. It's a little lamp that plugs in-between the injector & it's wire. Try to start, & the lamp should blink along with the injector firing.

DIY way...

Each injector plug has 2 wires, one of which is the same color for all 4. I think either yellow/black or red/black, depending on year. That wire should have power whenever the key is turned on.

Set your multi-meter to measure 0-20 volts DC or some range above 15v.
Hold or clamp the black meter lead to the negative battery post or to a good ground.
Unplug the injector & put the red meter lead in the plug for that wire I described above.
Key ON (don't have to start) the meter should read 13v or something like that.

 

Verify battery voltage as Jim Blake mentioned.

You can use the telltale bulb as a noid light.

Unplug the injector connector and hook the light across both leads. The light should flash when you try to start the car.

 

If the light DOESN'T flash, you'll want to know why.

1) Lack of continuous voltage on the one wire.
Test by using the meter (or test lamp) from black/yellow (or black/red?) wire to ground.

2) Other wire failing to switch ground on & off.
By elimination after you test #1.

 

I am that there was no resolution of the poster's problem. However, I have read many posts (from tons of sites) and have taken everyone's advice in account and have compiled a list to diagnose the same symptoms (stalls when warm/hot) :

1 - Replace the fuel filter, its cheap and easy!
2 - When the car dies, always listen for the fuel pump.
3 - If the CEL does not come on when you trying to restart, change/resolder the main relay.
4 - If the CEL comes on but the pump doesn't check fuses / replace pump.
4a - Perform the Fuel Pressure in a cup test
5 - Put a test light on the black/yel wire should be on while ignition is on - if not then check fuses, main relay
6a - Connect a timing light (TL) to battery and any plug wire
6b - Tie wrap the TL trigger on at all times
6c - Start the car, let it get hot and rev the engine
6d - Observe the light, it should never go out - if it does then the engine has stopped firing the spark plugs.
6e - Since you have previously verified power in step 5, then problem lies in the distributor
6f - Remove the cap, check spring, remove rotor, carefully remove ignitor module while inspecting wires for damage
6g - IMPORTANT: Since it is failing when hot check for a generous amount of thermal (white) paste between the module and dist - little to no paste and the module will overheat, no doubt about it. This is why a new one comes with the paste and you must use it where the module contacts the dist.
7 - Apply new thermal paste (aka dielectric grease) to the module and reinstall.

I am stopping here because the thermal paste was the root cause of my problem. I hope this helps.

If the module had been defective, I would have bought a cheap cheesy dist from ebay for $80 (dist,module,cap,rotor,sensor,everything) and replaced the whole thing.

Don't flame me, you know most replacement parts come from the same (crappy) Chinese factory so why not buy everything all at once for the same price? Shoot, buy 2 and leave one in the trunk as a spare.