1988 chevy truck won't start

Hello, just had this problem myself. Check your EGR valve by pulling the vacume line off and pushing up under the valve put your finger over the vacume line hole and release the valve, if it returns to normal position then its bad if not its good. If its bad it needs replaced. Mine did the exact same thing and thats what it was. Hope this helps

Turn the key forward and listen to see if you hear the gas pump run.or have some one put there ear on the gas tank door.also air out the fuel line there may be air in the fuel line.

Put gas in carb just to check I'm sure you will get it

Could be the crank sensor or something in the wiring. Each cylinder has its own coil, so it would be something affecting more than one cyl.
If it won't start at all now, you will have to figure out if it is a lack of fuel to the injectors or lack of spark to the plugs, or something else.
Are you saying the check engine light does not come on when you turn the key on, or just not when it is running rough ?

On electronic fuel injection pumping an pumping an pumping the gas pedal does nothing without the engine running ! Pushing the gas pedal to the floor will cause the PCM - engine computer to go into clear flood mode .

You have some very interesting ideas here , but not really how it works or is !

The vehicle will go into closed loop fuel control when the engine coolant temp reaches a definded temp an the O2 sensor get hot.

She would run for a couple minutes and die which is open loop when running, closed loop is when the sensors kick and it would die. Pulled spark plugs, they were black meaning no spark. Can only be 2

Black spark plugs indecate a rich condition , over fueled , wet spark plugs indecate no spark .

Inside or directly under the distribitor cap is a plastic ring with either one or two wires attached..... these devices fail and not allow the engine to start.
It happened on my 88 chevy (305 cu in.). a quick fix is to replace it with a new one.. (Advance Auto) or other parts store.

If it was running yesterday and only cranks this morning you need to determine which you are missing - spark or fuel. The spark is easy - pull a plug and let it spark to the frame. while cranking. If you have spark then you have to start checking the fuel system.

i had the same problem, and it turned out the coil pack was moulding inside wich stopped the spark all together, i ended up changing my coil pack and putting on new wires because the ends connected to the coil were very corroded and that cures the not running part just fine


enjoy

Try checking those sparks again. It could be a weak spark not enough to start your engine.
Make sure also that you have fresh gasoline, as gasoline or diesel looses it's effectiveness after a long time.

check to see if you can hear the fuel pump running.just cycle the key to the on position but dont turn over the motor you should hear a humming sound come from the fuel tank.if no sound check your fuses if all ok could be a bad fuel pump
or check to see if you have spark if no spak then it could be the module inside your distributor cap.it also controls the fuel pump.
samboiv