1994 will start then idle down and die after 5-10 seconds

[Hrb00drow]

Just bought a 1994 Explorer XLT. When I start it, it will run for a good 5 seconds @1200 rpm, idle down to 800 rpm then sputter out and die. If I hit the gas while it is dying it will stay running.

What could the issue be? I'm pretty new to this stuff.

 

[natenkiki2004]

Sounds like the idle air control motor is doing it's job but somethings not right at normal idle. Typical thing would be vacuum leak, maybe clean the MAF sensor.

Is it giving you a check engine light?

 

[vq5speed]

Sounds like a vacuum leak.

 

[Gadget X]

Maybe fuel delivery, whether due to a clogged filter, weak pump, or something related. Iirc, a vacuum leak will cause a high idle speed? Good luck with it!

 

[Hrb00drow]

It is not giving me a check engine light and as of the other day it wasn't pulling any codes. I will check out the suggestions when I get home today. Thank you.

 

[OneofMany]

I tend to be suspect of the IAC too, but usually it cause the engine to die right after starting. Also check your egr. If it is stuck open it will inject too much air into your air/fuel mixture.

 

[SammyM00782]

I have the same truck with the same problem but I can isolate mine to happening only after the truck has been running already and it's not consistent. If you give it gas it'll stay running but sound and feel like a miss. There's something wonky with the EGR I think, I can't remember the code right now but what happens is as I creep out of my neighborhood at minimal throttle you can feel it stutter slightly for about 5 seconds, engine light (which burned out actually) and then it's fine.

 

[fritz24]

As they mentioned iac-hell yeah. but a Vacuum leak??? Hell noooo.
Faulty Engine coolant temp sensor-check for corrosion and cracked insulation. This will cause the engine to stall start up if stuck on hot.
fuel delivery- check if fuel system holds pressure with KOER to KOEO for about 60 sec. report back

 

[the_don]

fuel pressure should be 30-45psi with vacuum hose attached to the fuel pressure regulator
40-50psi with vacuum hose disconnected, and must hold at least 30psi for 5 minuites after engine is shut off. but i would look at the IAC first.

 

[Albino 94LTD]

Check the fuel pump relay in the power distribution box under the hood.

For a test, swap it with the WOT relay.

If that fixes the issue, replace the original suspect relay with a genuine Ford part NOT and aftermarket one. The original Ford relay has lasted 21yrs.

 

[MUDDYTOES]

Mine did the same a couple days after getting back from a long trip. If it dies at low idle but runs with higher rpm it's a vacuum leak. My 93 caught a leak at the brake booster an made it so I had to really stomp on it to get the darn brake pedal to move.

 

[crpowell67]

I would look more towards a vacuum leak specially in the plastic/nylon lines not saying it is not something else but start with the easiest first real easy to check lines.