A year ago I bought my deceased father's 1993 Explorer, this was the last thing he ever drove and has sentimental value to me...it has only 85,000mi.

Yesterday the check engine light came on. The Explorer was running fine before. I drove 20mi to my destination and noticed black exhaust once I arrived. It started fine when I left, but ran rough. On the way back it stalled several times while slowing down and chugged some. Temperature gauge seemed to show fairly rapid changes in temperature but all in the normal range. Then it died again and had to pull over. Waited a few minutes and gave it lots of gas pedal and it started again. At this point I was about 20 miles from home. The engine would die frequently if I slowed down or stopped but I was able to drive it home, could not drive it in the garage due to it not being able to stay at idle. I tried to gun the engine several times to start it, and noticed that the power steering fluid cap had popped open and fluid was spilling.

How bad is this?

 

Sick, but far from dead.

First thing to do where the check engine light came on would be to pull codes from the computer. I know Ken00 has posted instructions from his manual for this at the top of the BII and Ranger forums. Only requires a paper clip.

 

It sounds like your fuel pressure regulator has died. It would cause all those symptoms upon failure. When you floor the pedal when cranking on a EEC-IV vehicle the computer turns off the injectors, this means that when you did this and it started the engine was flooded.

 

I don't have the equipment to do a fancy computer test. Aren't those 50,000 dollar machines designed to rip customers off? In any case, I'll try to find the instructions you mention if it can be done easily.

I'll see about the fuel pressure regulator...where is it?

thank you, I hope it can be made to run with reasonable expense...

 

I second the FPR diagnosis, it is secured to the rear of the fuel rail (near firewall)with 2 10mm bolts and has a vacuum hose connected to it..

 

thanks, but I still can't find the Fuel Pressure Regulator. I've worked on other cars before and never saw such inaccessible parts for such a big car (good luck with the spark plugs!), this is frustrating! I do not see anything that looks like a "rail". I would assume this is some structure supporting the injectors and it may be buried deep under the air intake system, but it is not visible as far as I can tell. Is the FPR accessible or does it take major disassembly of other systems? The firewall is crowded with all sorts of stuff and there are multiple ones that have vacuum hoses...help! Does anyone know more or less where to dig?

 

On my '92 4.0, the FPR is on the front end of the fuel rail, kind of right underneath the throttle body. It will have a vacuum line coming off of it, and a high pressure fuel line.

 

FOUND IT! Thanks! It is below the front of the throttle body in my 1993 Explorer. maller than I thought and with a very thin vacuum line and a braided steel gas line attached to it. Now that I know where it is (more accessible than the passenger side spark plugs) I have to decide if it is broken.

What about the IAC (Idle Air control)?

What about the MAF sensor? How do you clean this part?

 

What do you want to know about the IAC and the MAF? The MAF is normally cleaned by removing the part holding the filaments out (need security torx bits available at most any auto parts store) and gently cleaning the filaments with a non-residue cleaner (I use isopropyl alcohol). Normally one starts diagnosing problems with the MAF by pulling codes from the computer as I originally suggested. IAC can get dirty and cause idle issues, and it can be easily cleaned with throttle body cleaner.
Best first check of the FPR is to pull the vacuum line off and see if it's full of gas (gas=bad FPR). If it looks ok, then get a fuel pressure gauge on it and jdo a fuel pressure test.

 

I just wanted to know if the problem could be the MAF as I read on various other posts. Another post I found suggested it might be the IAC. I tested the IAC as he described and it was apparently shot. I bought a new one and now the Explorer can be started, but it idles erratically.

I do not have equipmet to "pull codes from the computer" and the truck could not be driven. Now that it seems to run I can drive it to Autozone to hopefully get these codes. I'm just afraid it won't make it to Autozone.

I will check the vacuum line as you suggested and see if it has gas.

 

You have to remember.. the computer may have to relearn how to idle and all with the new IAC.. sometimes that takes a few miles.

And yes it could be the MAF... although usually when it causes drivability problems, it's usually more like cutting out or no power... doesn't typically cause idle problems.. although I'm not going to automatically rule that out.

As far as your P/S cap being blown off, that's from turning the wheels with the engine off... pushes fluid up into the resevoir, causing excessive pressure and the cap blows... as long as it isn't broken just top-er-off and put the cap back on.

Let us know what codes you get (if any)... good luck

 

BTW... when you are ready to do the plugs, go in through the wheel well. It's much easier than from the top.

 

All the equipment that is required to pull codes is a paper clip, then count the flashes of the check engine light. As noted, instructions for this have previously been posted here, or you can fiind instructions all over the internet or in any good repair manual.
If you prefer, code readers can be obtained for as little as $25. I believe these usually come with adequate instructions.
If you want to try to go to Autozone, you can. Sometimes they'll pull codes for you, other times they'll tell you they can only do '96 and up OBD-2 vehicles. I think it depends on how knowledgable the Autozoner is. Because it can be hit or miss when going to Autozone, I would suggest you learn how to do it yourself.

 

Found and checked the fuel pressure regulator. No gas when I pull the vacuum line.

Went to Autozone (with a Mitsubishi) and they don't read on "old" Fords. My Explorer is an "old Ford"!!! Also they had just sold the last code reader for about $ 30...

I did not find the paperclip trick...but I will look again. Is it really worth the trouble? It seems computer codes give you many possible problems, like you all kindly gave me already!

Thanks for the answer on the power steering leak...that is exactly what I did (turning the wheel with the engine off...it's good exercise!)

Also thanks on the advice with the wheel well spark plug removal...I'm sure it will save a lot of trouble.

A mechanic suggested I clean the EGR ... where is it?

I will go to the library to find a Chilton's manual to learn more on the engine layout. I will find the EGR and look on the manual about the paperclip code thing and search more on the web. I promise I will let you all know how it comes out. Meanwhile keep up with the advice, it is much appreciated!

 

"I did not find the paperclip trick...but I will look again. Is it really worth the trouble? It seems computer codes give you many possible problems, like you all kindly gave me already!"

Computer codes tell the story - they are sort of a mixed blessing I guess, esp the more sensors a car has on it, but you should get those codes read, so you don't end up spending time/money changing parts that are fine to begin with... it's expensive to just "throw money" at it, and guess.

Something like a rough idle, could be 10 different things... the computer knows why the engine runs rough - so LET IT TELL YOU!

it could be something simple, or not, but you have to start with codes - you can buy an OBD1 reader for under $50 on ebay if you can't find one anywhere else, or find a decent mechanic that will read them for next to nothing, or don't want to do the paper clip thing...

it's the first thing you need to do... we are all trying to help you, but codes are the only real way we can start to shed some light on what the problem(s) are...