Cranking but not starting
 

Hey guys,

So I've got a 93 sport 2WD. It's got the auto 4.0 L straight 6. So issue is, I've replaced the ignition coil, rotor and distributor cap. I'm getting spark but it won't turn over. It's just spinning and cranking but not turning over. All other systems normal and it was running fine until about 3 pm CT. I shut it off and when i tried to fire back up it just spins. Battery and all fluids are good, checked fuses and they're good. Do you guys have any ideas on what i should try from here?

Thanks

cranking = turning over.

Your condition is cranking, but not -starting-. Or in mechanic speak a "crank-no-start".

If you have tested for spark and know that you have it. That typically leaves air and fuel as the primary culprits. That is assuming there were no recent over-heat conditions, or something like that.

For air, the the most common problem is the Idle Air Controller not opening and letting air in during the start (it also regulates air when your foot is off the pedal to control the idle RPMs). You can sometimes test this a little yourself by feathering the gas pedal while cranking to see if it tries to start.

For fuel, the first place to check is the fuel pump. You can test the fuel pressure by connecting a fuel pressure test gauge to the fuel rail. Some autoparts stores rent this device. You can also simply press the shrader valve on the fuel rail during cranking to at least check that there is any fuel pressure at all. If fuel does not come spraying out under pretty high pressure - it is a sign that the fuel pump has either failed or is having a problem with electrical connections. You can also youtube terms like "testing fuel delivery" to find out how to use starter fluid sprayed into the throttle body. If the vehicle starts and runs for a few moments - this is another indication that fuel is culprit.

I've tried checking the air as well. it's getting air fine and i've tried feathering the gas with no change. My FIL is a mechanic and has been helping. We've tried fluid in the TBI. It was getting fuel with no issues earlier this afternoon and previously. No overheat conditions.

How was spark tested?

What kind of fluit? What was the result?


How did you determine that?



You need to stop being so stingy with the information. Spell it out. We can't help you if we don't know what's going on, and this Twenty Question routine gets really old,, really fast.

"It was getting fuel earlier this afternoon with no problems"

I assume you know that it was because it was running. So you tested and now know it ain't getting fuel at the rail?

"We've tried fluid in the throttle body"

And what happened?

Lastly, when you turn the key to on, do you hear the fuel pump hum for a second?