hi, i just purchased a 93 explorer with engine problems and i was wondering if you could help me figure out what is wrong with it. when i start it up it will idle just under 2000rpms and then hesitates and dies.

 

Well, a lot of things could cause this. Some possibilities:

You could have a vacuum leak. A vacuum leak is usually accompanied by a whistling or whooshing sound. It can be caused by a vacuum hose that is cracked or has a hole in it, or one that is disconnected or missing. Did you recently work on the engine? If so, you could have unwittingly broken or disconnected a vacuum hose. A vac leak could also be caused by a leaking gasket.

Might be a problem with your idle air control (IAC) valve. The IAC valve has an electrical connector attached to it. Is that connector loose? If it's on tightly, do you have voltage at the terminals? To find, test and, if necessary, replace the IAC valve, click on this link: https://www.ford-trucks.com/article/...r_IAC_Fix.html.

Could be a defective EGR valve. The EGR valve has a hose attached. Is there vacuum at the hose when the engine is cold? There shouldn't be. A thermal vacuum switch (TVS) should prevent vacuum from getting to the valve when the engine is cold. If there is vacuum when the engine is cold, you could have a faulty TVS.

Is your check engine light on? If it is, you'll need to pull the code(s). Many auto parts stores will read the codes for free.

Do you need to apply much more pressure to the brake pedal than usual? That would indicate either a faulty vac booster or the large vac hose that goes to the booster is disconnected or damaged.

If you can provide more info, it would help pin this down.

Good luck!

 

Pull the codes even if the CEL is out. There can still be code stored.