Engine dies when....

[AirForceFiat]

Ok my 81 spider starts ok and will idle fine until I apply the brakes it kills the engine, but not every time. Sometimes I can apply the brakes and it still runs fine until I flip on the headlights then the engine dies. And then when I try to restart it it fires up then dies immediately and continues to do so. Does anyone have any idea what is wrong with it? Alternator bad?

[Fi8spider]

Basics first I guess, is the timing and idle speed ok?

Vacuum leak maybe?

A brake booster leak from the white plasic right angle fitting can make it idle rough or cut out when the brakes are applied. There should also be like a metal one way valve in the brake booster vacuum hose from the manifold that can cause grief if it's faulty, especially if the idle speed is set too low it wouldn't take much more load to help the engine die.

[AirForceFiat]

I didn't notice any vaccume leaks, but I'll check again, and would that cause it to not start up again when it dies?

[RoyBatty]

Possible short to ground in the electrical system for the lights?
Could be robbing you of power needed to light the ignition system.

[GeorgeT]

Check you alternator: I had the exact same issue and it turned out to be a bad diode in the alternator. The alternator did not put out enoghh "juice" to run the lights and the motor; replaced the alternator and things were fine again.

[AirForceFiat]

Ok found no vaccum leaks and had alternator tested and it's good, but now engine died after about 20 mins of running, it died at idle and won't restart. I already replaced the coolant temp sensor what else could make it do that?

[rlux4]

It could be a number of reasons. You need to check what's missing from the equation when it won't start. Spark, fuel, or injector pulse.
If the car will run OK then we can assume timing and compression are within limits, so that leaves the three.
When the car won't start check a plug wire for spark, then put a stethoscope on an injector and listen for a clicking, and then check that your fuel pump is running.
Ron

[srwilson]

Have you checked the coil and coil wire? Sounds like an electrical issue to me. Pull a plug wire and see if you got a spark.

[digitech]

One thing to look at (what happened in my case anyway) is to check the voltage at the coil. When I loaded certain portions of my electrical system, it dropped the voltage supplied to my coil below what was needed to run the ignition. Left me sitting more than a few times and chasing my butt until I got it figured out.

[AirForceFiat]

Also I replaced the ignition coil, ignition control module, rotor, cap, plugs, and wires. Also just off topic, does anyone know where the EGR is exactly located on this thing? I failed NOX emissions:(

[rlux4]

Unless your car has been changed from fuel injection you don't have an EGR valve. Or a smog pump. Or a mess of hoses and lines related to them. About all you need is the cat and crankcase vent. The ECU (electronic control unit) controls fuel/ratios so if it gets an incorrect signal from a sensor it would cause bad combustion. The most critical sensor being read by it is the temp. sensor in the coolant T. Not the one on the bottom of the radiator, it's for the fan.
Ron

[So Cal Mark]

Nox is caused by high cylinder temps, so over-advanced timing and lean mixtures can raise levels drastically. Make sure the timing is correct and the CO is set right

[bobplyler]

I had a similar problem. It ran fine until it got hot, then would cut out and not start for a while. What was happening was I had a pinhole leak in one of the radiator hoses. When it got hot, it would spray a tiny mist on the coil.

[AirForceFiat]

Ok well I've got no leaks, other than an oil leak, but it seems like even when I shut it off with the key after its been running it won't start up again either... Will do more testing today

[AirForceFiat]

Ok new update, after running good for about 30 mins if the rpms were below 2500 the engine would shudder and sputter for about 30 seconds then die and would restart for about 1 second and die again. Now testing the spark it looks like I'm not getting any at the plugs. I've replaced the ignition control module, ignition coil, cap, rotor, plugs and wires and the pickup wires are not new but they look ok what else is there?