Rough Idle, loss of power, horrible gas mileage

[Theguy155]

Good afternoon gents,

First let me say I love this board, I love you guys, and I have been a member since I was in high school, I am now out of college, with the same '93 Explorer Sport none the less!

Anyways, I searched through the boards and found a number of threads on this problem, but I figured I would go ahead and make one of my own as well.

Here is whats happening. She has 218,000 miles on her and recently I have had a lot of trouble getting her started in the morning, after leaving her in the garage after I get home. The longer I leave her, the longer it takes to get her started in the morning. This morning took about 30 cranks for her to finally start. She will start the first time after I drive around and warm it up for a while. This has nothing to do with temp. though. I am in TN right now and have live in the south all my life, so it is not the heat that is affecting it.

After she starts, CEL is on, she has a rough idle, around 1000 rpm, and gets absolutely no power when I drive around. It is a 5 spd manual, you can also feel the buildup of back pressure when I drive(why it is getting no power I'm guessing). She is getting horrible gas mileage, like ~200 miles to the tank. Also, the fuel pump is staying on instead of cutting off after 2 seconds right before I crank it. This makes me think it has something to due with the fuel pump/fuel line, but the fuel pressure is fine. I just had it tuned up recently as well as changed the plugs and cables. The vacuum is fine and there are no leaks.

Here is what I have done: Full tune up, Checked battery/alternator, changed plugs/cables, changed air filter, fuel filter, cleaned throttle body, changed PCV, put in new IAV, new fuel pump relay, checked MAFS

I have not pulled codes yet, i just now read that thread on doing it with a wire/paperclip so I may have to try that. By the way, do any of you know how to pull codes on the 1st gen?

Here are the things I think it may be: Injectors, clog in fuel line/fuel pump, 02 sensor, computer

Thanks for the help gents, yall are great!

Please excuse if my question is simply answered, I haven't posted on this site in a long time.

BLESS!

 

[turboranger91]

do you hear any rattling coming from the exhaust at all? i knew mine was bad, and that the cat was busted (so it made a bunch of noise at idle), but last week, it must have gotten much worse. i had to floor it to go anywhere. i had no choice but to hack the exhaust off. once i did, it went back to it's normal amount of power.... it's just REALLY loud and has no back pressure now. have to get that fixed this week.

 

[Theguy155]

its not the cat, also, i forgot to mention that it is running very rich, and may not be running on all 6 cylinders

i too need to fix mine this week

 

[Theguy155]

I am thinking it could be an O2 sensor, injector, EGR valve, fuel pump, or possibly the computer. Any help is much appreciated. Thanks again gents.

 

[muhl5443]

if its running rich you probably have a sticking injector. although the o2 sensor and computer could be doing it too. its hard to say with out looking at the vehicle and diagnosing it. as far as the starting and running rough problem sounds like it could be intake manifold gaskets. my 98 did the smae thing a few winters back i had codes p0171 and p0174 and did both the upper and lower intake gaskets and problem was solved.

 

[Theguy155]

excellent thanks for the looks guys

the growing list of things it could be:
O2 sensor
injector
EGR valve
fuel pump
the computer
cat
intake manifold gasket

i dont think it is the cat or the manifold gasket though, i checked them out and they are fine

i know this is a common problem, there are a number of threads on here about this type of thing, im gonna go back and take a look at those and then go check it out myself this afternoon

we'll keep you guys informed

 

[MrShorty]

Did you ever pull codes? Reading threads on here is a useful exercise, but, where the CEL is on, that suggests that your computer wants to tell you what problem it is seeing.

 

[Theguy155]

i just tried to pull codes using the paperclip method aaaand........it no worky, i dont what i am doing wrong, i followed the thread on how to do it, i tried the KOEO method, i dont have a scanner, i am going to go try it after posting this though, i just took it out for the first time today so she's warm now, took about 15 times to start this morning though

i am beginning to think it may be an injector that is sticking, i did put some injector cleaner in and that hasn't seemed to help anything, all that gas has to be going somewhere cuz it is getting horrible gas mileage, and that would account for the trouble with starting and power issues as well, and it really sounds like not all the cylinders are exploding to me, it sounds like a freakin go cart engine

i ran into another thread with a post that said something about a mustang with this problem, guy said his injector was sticking and basically just dumping fuel into the cylinder, i'll try to find it

by the way MAJOR gas smell, obviously running very rich

 

[Theguy155]

just tried to pull codes again...to no avail...i dont know what im doing wrong, there is not much too it, and im pretty sure im doing it right, im not that big of a dumbass and its not like its rocket science, i tried it in KOEO mode with a paperclip, its not giving or flashing me any codes, the CEL just stays on as well as the fuel pump

this could be a grounding problem somewhere

thanks for the input guys, glad to see this board is still active like this, i think i might take her in to see if a mechanic can see what is wrong with her this week, i have got to figure out what is wrong this is killing me

 

[MrShorty]

tried it in KOEO mode with a paperclip, its not giving or flashing me any codes, the CEL just stays on as well as the fuel pump

This sounds almost like you are grounding the fuel pump test lead rather than the STI. Beyond that, we pretty much have to assume you're doing it right. Maybe check the wiring between the self-test connector and the PCM to make sure there isn't a wiring problem there.

 

[Theguy155]

i double checked how i was jumping it to pull codes, as far as i can tell i was doing it right, did it just like it says in the thread and in the manaul

unfortunately i broke down and took it to the shop today, i hate it but i just dont have the tools to fix it, and this problem is a little beyond my knowledge i think, i think it might be the injectors, its getting the worst gas mileage ever, 60 miles since i filled up and half the tank is gone, its getting almost no power too, it barely goes when i gas it, CEL light on, hard to start after leaving it over periods of time, it sounds like a go cart engine when i finally get it started up

thanks for the help guys, hopefully we will have an answer by tomorrow

 

[Wakeboy1337]

Your computer is most likely in FAIL mode (code 998) and this could also cause the scanning to not work. Try another computer.

 

[Theguy155]

wow...just got word back from the tech...it needs a new computer...im gonna research this...but could anyone be a good sport and point me in the right direction?

 

[mawrazen]

Local junkyard $50.00 dont ask how I know. LOL

 

[mloyacono]

My '92 Explorer is having the same basic symptoms as yours, I took it into Ford about a year ago, and they could not find the problem. I think that I will take it into my local shop and see if there are any codes. Have you replaced you computer yet?

 

[Theguy155]

Sorry for not updating my own thread, there are so many threads on this topic that I found another one and started posting in it.

Here is the link to said thread:

http://www.explorerforum.com/forums/showthread.php?t=282241&page=3

Anyways, I got a new computer from advance auto parts (best place to get them IMO) and will be installing it this afternoon. I am really hoping this fixes the problem and will keep you updated.

The new EEC from advance was 166 total, but they give you a 45 dollar refund if you bring your old one in, its called a "core discount." I highly suggest going to advance auto, they are always so helpful and if they dont have everything you need, they can order it very quickly. The mechanic working on my car quoted me 700 + dollars to replace the EEC . 475 for parts and the rest was labor and tax...AND it was going to take them about 3 days to get the part. So it would cost me over 300 more dollars for parts and 3 extra days if I let them do it for me. Instead I literally walked .1 miles up the road to AAP and saved over 500 bucks, AND they are getting the part to me is less that 24 hours, pre-flashed, ready to go, all you got to do is plug it in.

What kind of crap is that? I mean really, I would like to know where that mechanic is finding a new EEC that costs 475 dollars. That must be some kind of super computer. Oh ya, and every other place I looked online was like $250 or so. Advance for the win.

Here's to hoping this works!

 

[Theguy155]

mloyacono: you can try to pull codes yourself by jumping the EEC tester plug with a paperclip or peice of wire, there is a thread that tells you how to do it, it is a 'sticky' on the main page of the 'stock 91-94' forum, i suggest you try that, it is very easy and that is how i figured out that my EEC was bad

 

[mloyacono]

Theguy155, Thanks, let me know how replacing the computer works for you

 

[Theguy155]

will do, wish me luck, im gonna need it

 

[Theguy155]

alrighty gents, the new ECU came in today and is now installed, started her up and the CEL was not on and all of the symptoms were alleviated, drove her around for a few miles and she did just fine, good power, good idle, no stalling, easy to start up, fuel pump runs for 2 seconds

thanks to all once again for your replies and support