'93 Sport with CEL on, stauls at a stop, loss of power

[Theguy155]

Hi,

I have a '93 Explorer Sport that has 150,000 miles on it. I have replaced the catalytic converter and the thermostat so far. I really have not had any other problems with it, however. I do a little bit of off-roading and trail riding. I have a 3" body lift with 31" tires as well. Recently, the CEL has been coming on sporadically. It experiences somewhat of a loss of power, and sometimes, at a complete stop, the engine will idle, then gradually move to lower RPM's and eventually shut off. This happens rather quickly, however. I believe this is a fuel problem. Possibly something with the fuel line, fuel pump, spark plugs, or even the vacuum. Any comments on this would be greatly appreciated!

Thank you.

 

[Cali' Explorer]

My first thought would be the Fuel Pump or, more commonly, the Fuel Filter.

I don't know much about the older X's, but I guess it could also possibly be the FPR (Fuel Pressure Regulator).

Also, when you say the CEL comes on Sporadically, do you mean that it will light then immediately go out, or is it that one day it will be on the whole drive, the next day it will not? If the light stays on long enough to go get a code pulled, that would definately be more useful.

 

[MrShorty]

With the check engine light ocming on, the first thing I would do is run the self-tests. Only requires a paper clip (www.dalidesign.com/hbook/eectest.html). Start diagnosing the KOEO hard faults until that portion of the test gives a pass code (111), then move on to the KOER test. After getting a pass code for the KOER test, clear the codes and see if any continuous memory codes that were present return. Then resolve them.
Most fuel delivery problems can be diagnosed using a fuel pressure gauge.

 

[guppy274]

Check your vacuum hose first, its cheap. If you leave it alone it will get worse too the point where you can't take your foot off the gas without it stalling at lights or really low speeds

 

[Opera House]

Fuel pressure regulators are known to stick open when they wear unevenly. Initially this is more likely to happen at high vacuum conditions - like when stopped at a light. You might want to consider monitoring the fuel pump current. I did this by pulling the pump fuse and running lamp cord to a meter in the cab. Many crimp on wire terminals easily fit into the fuse socket. Current is about 5A and the engine will stop at about 2A. This will definitely tell you if you have a fuel problem, but not specifically tell you what it is. Easier that hanging a fuel pressure gauge on the hood.

 

[otterfluff]

Listen for any hissing (vacuum leaks) under the hood. I had these exact same symptoms, ended up that I had just blown a vacuum cap off.

 

[Theguy155]

I'm sorry, what I meant by sporadically was that I would start the car, then drive for a while. After just about 30 sec-2 min of driving, the CEL would light up. It would go off for about 30 sec-2 min while driving, and then light up again. I actually got the problem fixed this week. The problem was that my Mass Airflow Censor was broken. Ya, a new MAF and the tests they had to run to find out that my MAF was broken cost me a pretty penny as well!

 

[Glacier991]

It pays to read your own codes and go from there. As Mr. Shorty said it is easy on the 1st gens. The light does not have to be on to read it. The puter stores codes. Wouldn't it be a ***** if the code that was never read pointed to the MAF... would have just cost you the price of a repacement MAF. There is a lot of good information here, if you take the time to read and digest it. Can save you BIG bucks - but you get out what you put in, timewise.