98 Ford Explorer fuel system lean..

[bcart01v]

Hey everyone. First off I have to say that this website is extremely helpful. I've spent the last month reading over a lot of posts to get me where I am now, however I still need help.

I have a 98 ford explorer with a 4.0L. v6, OHV (vin x). I bought it 2 months ago with 155,000 miles on it. It was perfect. Drove amazing. Then 3 weeks into it my check engine light came on, ran codes, and I got Camshaft Position Sensor error. After finding out where it was located, I decided to see how long I could get by without changing it. The answer was not long, I started getting rough idle, loss of power, then sudden stalling. So I parked it, removed the hood and stood on a chair to replace the sensor. The old one was completely broken and hollow. I changed it (4 hours later). But driveability remained the same. Plus my check engine light was still on. I ran codes again and got, Fuel system to lean in bank 1 and 2. No clue. I got on here and started checking off things.

First, the car dieing stopped after the cam sensor was changed, still loss of power and rough idle. After some voltage tests I determand that the MAF sensor was bad. Replaced that, and now the rough idle is pretty much gone, but loss of power and error codes remain, I checked the PCV valve and it seamed good, but replaced it being that it's cheap. I did notice that the valve had oil inside of it. Not sure I lf that's normal, but I couldn't find anything that said it was or wasn't bad. Checked the EGR, I could hear and feel it move, checked the pressure going into then egr pressure regulator and it was perfect and didn't flux. Hooked the output to the egr line To my vaccum testor, and it kicked on whenever it needed to. So. Now what?

Here is what I can describe as what happens. Now, it is getting cold out, and my engine rarely moves from then Cold line, I'm not sure about that either. Now. When I push on the gas to go around town its semi ok. It will get up and go alright (not like it used to). But when I get on the highway, once I give it gas, you can feel it loose power, kinda shutter, the rpm guage will rise but it's def. Not getting power, and then the engine starts heating up, finally moving away from then C notch. I'm not sure if that's important. But it happens. When I get to the speed I'd like, when i let off the gas you can feel power coming back. And its not to hard to maintain speed or speed up slightly. But a lot is a no go.

Also, takes several cranks to start. Where should i look next? I'm running out of ideas and good weather.

Thanks for reading and ideas.
Ben

 

[bcart01v]

Well, spoke entirely to soon.

Just as soon as I thought I making progress, things go in the opposit direction.

Yesterday morning is when I installed the new MAF sensor, ran fine, went to work had no problems, then after i got off work things went south. Driving home on the highway my check engine light starts flashing, I loose power instantly and my engine is shuttering like no other. I get off at the first exit, Check engine light stops flashing, remains on, and everything is back to normal, for about 2 miles. Eventually i start loosing power all together, im going up a fairly steep hill at a whoping 5MPH because it just wont go, trying to push the car down the hill, it refuses everything i try to do, and eventually just stops. The engine is still running, but idleing so bad, my RPM guage is falling below 0 but somehow its not dieing.
I pop the hood and take a look, i have exaust comming from the back of the engine. I didnt have a light and I'm un-sure of where it came from, or if it was even exaust and not just something spilling onto the exaust pipe. How ever, during this hole time my engine temp. is still sitting at Cold. I had it towed home.

Today I bought a new ignition coil, because the one on the engine was the original for one, and failed the tests my book said to do. BUT, did not fix the problem. Now, mind you that when i woke up this morning and started it, of corse it cranked forever but still fired up. But after warming up it starts idleing rough again.
Im getting a new code, Random multipul missfires, so thats why i looked at the ignition coil first. Still getting the error code though.

After removing the ignition coil however, i did happen to find the fuel pressure regulator (now anyone can correct me if im wrong but im pretty sure this is what i saw, the Fuel pressure regulator is just forward on the engine from the ignition coil on the 4.0L OHV?), like i said i found the fuel pressure regulator, but it had no vaccum line attached to the bottom of it, even though the diagram showed one runing to it. Now i looked forever and couldnt see any vaccum line near, around, or free, so im not sure about that, however its pretty obvious that it hasnt been hooked up in quiet some time as the nipple on the bottom is just covered in dirt and dust.

Im at a loss here, next on my agenda is to check and clean the 02 sensor, replace the fuel filter, and then pray that fixes it. I'm also wondering, could this all be caused by a clogged catalyitic converter? I've had vehicles in the past that showed these same problems and with a simple drilling into the exaust took it all away. To me it just seams not enough air is leaving the engine, and that would explain why i was getting exaust comming back into the engine.

All thoughts, seams like im just taking a shot In the dark at this point. Any help or insight is more than welcome.

Thanks in advanced.
Ben

 

[bcart01v]

Update everyone.

Well, today, went out, had a heck of a time trying to get it started. so, I took off the Idle air control sensor, cleaned it out, retested my map sensor, and then i noticed that my neg side of the battery was loose, real loose. It just slid right off when i pulled it, noticed i had a heck of a lot of build up on the terminals, so i cleaned the off, patched everything else back up. And it fired right up...

No error codes, so i drove it around. Alot. and i pushed it hard, very had. Its very responsive, no rough idle. No error codes...
Not saying that this is a bad thing, but lets just hope this keeps itself up.

I'll keep everyone posted incase someone is having the same troubles (which seams to be a common code in a lot of explorers, but not a common fix.

 

[bcart01v]

Well new update.

After driving around for a day the check engine light came back on, got rid of the random missfire code but still mixture lean in bank 1 and 2.
took it to a shop today and they suspected bad 02 sensors or a clogged cat. I doubt that both 02 sensors would go bad at the same time, but weirder things have happened. I'm going to try the seafoam trick to see if that helps. Also read if you unplug your battery overnight it could turn up some new codes. In some.cases fix the problem. We shall see.
Unfortunanly Oklahoma's getting a good blizzard/rain mix, so i have to wait on working on it.

 

[bcart01v]

New update again.

So I tried unplugging the battery for 8 hours, plugged it back and, started it up semi fine. Drove to work, no problems, no error codes. Drove home, no codes. Go to the store, check engine light comes on. Figure its late in the day I'll check it tomorrow. Go to Christmas party, fine. On the way home on the highway, fine. Got off the highway about a mile around, loose all power. Pull over, it Comes back. Drive a half mile, lose power again. Pull over, it dies. Figure I'll wait till it cools down. Start it up, rough idle, dies. So I unplug the battery for 10 minutes, and plug it in, start it, takes a few cranks, runs rough for about 30 seconds. Then it's like I flipped a switch, and magically its back to normal. I have power again. Now I did notice I lost power about twice but it didn't last long. Made it home.

Im confused.

When it quit on me, I put my hand up to the cats to see if they were hot, and they were luke warm, didn't seam unusual. I don't think it's the cats, cause it wouldn't start right back up from unplugging the battery I wouldn't think.
Could my ECM be going out? Or just a bad sensor that's randomly working when it wants to. Any ideas would be great.

Also, after leaving the battery unplugged so long, I noticed that the engine leaves the cold mark, and it was freezing today. It warmed up at idle, cooled down at acceleration, and warmed up at steady speed. Now it cools down fast. It could go from half between hot and cold, to cold in a solid 10 seconds. Not sure if that's anything.

And, if anyone has a 4.0l OHV, could you let me know if the fuel pressure regulator Has a vaccum line? I stumbled apon this regulator replacing the ignition coil, and noticed it doesnt have a vacc line running to it, even though the diagram said there is one. I've looked everywhere and I can't see a vac line just laying around unplugged.

Help!!

 

[bcart01v]

Quick question to ANYONE.

In the book it says that the X has a emergancy fuel cut off switch in the passenger side pannel, and in case of a wreck theres a button to push to shut off the fuel pump. Well when i was trying to test fuel pressure, I see a red button on top of the switch, but its stuck pressed down. My question is, does this button only activate during a crash, or could mine be broken? i had to unplug the switch compleatly to empty fuel pressure (changing fuel filter)

The faster the better, im looseing light lol.

 

[bcart01v]

Another update. Replaced fuel filter, dirty as all get out, now, ive got

Fuel mixture to lean in bank 2.

Not bank 1 and 2, just 2. So i assume im moving in the right direction. Next step is to take o2 sensors off and clean. i guess.

 

[bcart01v]

Well. replaced plugs on passenger side. Seafoamed. Still fuel mixture to lean bank 1 and bank 2. still runs like hell.

 

[bcart01v]

Alright everyone, new update.

Well. Its been 2 days since the fuel filter and seafoam change. Things are getting better. Starting isn't taking a thousand cranks, but more then standard. Idle is back to normal, the car doesn't shake or sputter at idle. Driving like a granny does the trick, still can't give it gas or it bogs down. I had a feeling either a fuel injector may be going bad, or its just still clogged. However I still can't find the vaccum line for the fuel pressure regulator. Oh well. I think im going to check the new fuel filter and re-seafoam. It was unbelievable how much gunk fell out of the old fuel filter. (original filter with 159,000 miles).

I think im moving in the right direction. Ordered some new o2 sensors online cause of the right price, and to rule that out.

Merry Christmas everyone! Hopefully Santa fixes my x!!

 

[bcart01v]

New update.

Changed the 02 sensors. Engine light off. Drove the crap out of it. Didn't have a problem. Still can't lay into it though, cuts out. But im sure the injectors are clogged after seeing that fuel filter.


But ultimately, my problem is fixed.

 

[bcart01v]

Spoke to soon

Driving around all day I had no problems, but I did realize that the farther i drove the more it started to bog down and start quitting.

right before getting onto the highway, check engine light came on, getting onto the highway was a pain, and keeping over 60 is near impossible. And never fails, soon as exited, it died. Was able to drive it to a lighted area where it died again, and unplugged the battery. Before so i ran codes (kept code reader with me..). What it read now is 0174(again...) and now, 1131, and 1151. didn't have my book, but after looking it up it seams that's the o2 sensors i replaced.

now after unplugged the battery, and it re learning how to idle i drove home no problems. I'm really starring to get lost now. I can't understand how it just gets worse as i drive. I had a 91 Chevy Lumina that did the same thing, and ultimately it was the electronic control module that was faulty, which i plan on going to a junkyard tomorrow to pick up.

When i replaced the cam sensor, i unknowingly unplugged the ECM, with my battery still plugged it. Now im not entirely sure if that could mess it up but the book is pretty specific on ways of handling the engines computer. im running out of ideas.

other boards have said check the.DPFE sensor, but i dunno, i feel that If the sensor was going bad It would just stop running, but then again me unplugging the battery would leave everything up to the computer which in-turn wouldn't be bad. I dunno. I'm just throwing parts at it at this point.

 

[ranger7ltr]

Two questions...

What did the inlet fuel in the filter look like and how long had the truck been sitting?

If the inlet side of the fuel filter looked like rust or coffee grounds the tank is done...I went through exactly what you are doing right now and the fuel filter would clog up after a couple of days or 200 miles...I even had a radiator shop boil out the tank and tried the POR-15 tank liner and the rust still came back...

Also if the truck sat for a long period rust can start and become the problem inside the tank where there was no fuel covering the metal tank...

I would change the fuel filter again, look at the inlet side of the filter, and if it looks rusty I would stop changing parts until I changed the tank...

Good luck and let us know what you find...

 

[joecrna]

I don't like the way your temp gauge responds. Do the hoses get hot to the touch? If so, maybe just bad gauge. If not, bad thermostat. Computer reads coolant temps and adjusts air/fuel. If temp sender is bad it will act erratic. Cant remember which sender is used by the computer off the top of my head though.

 

[bcart01v]

The fuel that was coming out of the fuel inlet was crystal clear, I made sure to capture some fuel out of the in and out lines just curious as to how much crud was I it, and To my surprise no dirt.

And for the hoses, they don't get hot to the touch, and as far as I know this truck was only sitting on the lot for a couple of weeks, however, I feel that who ever owned it before me, doesn't drive it as much as I do.

I found a used ECM for cheap, going to try that next. If anything I'll have a backup.

 

[bcart01v]

quick question.

Will a bad iac cause the problems?

With it un plugged it fires right up. But just won't run. With it plugged in, takes forever to start, runs like hell.

 

[bcart01v]

New new new new update. Lol.

So everyone, I bought a used computer from a 97 explorer that had an identical motor, and here was the result: AWFUL. I Should of known better, first of my car thought I was stealing it. The ac was stuck cycling on, and froze over, and shifted like hell. So I took it out, put old back in, and replaced the idle air control valve. The gasket that was suppose to be between the iac and motor was missing, but after replacing it my idle was smooth, still a lot of cranking. But. I had majority power back, I cruised on the highway at 75 with no problem (first time in a month) and I made it home without resetting anything. Engine light on, still fuel mixture lean bank 1 and 2, and im starting to think that my gaskets are shot, because my engine now has an obvious hissing sound, can't pinpoint it though.

And lastly. At the junkyard I did some looking, and the OHV's there had a vac line running to the fuel pressure regulator, mine does not. So I took the vac line off the ac and ran it to the fuel pressure regulator, dunno if this has helped, but I don't think it can hurt. Will go back tomorrow and pick up that line cause mine is obvious gone.

And lastly lastly, I will check the thermostat real soon, I have a sneaking suspicion that someone has removed it entirely, my thought on this, is that I basically control the engine temp with my foot. The more I give it, the warmer it gets, but it doesn't stay warm, cools instantly when i left off the gas. I heard that this could cause the vehicle to run lean or rich, to warm and cool the engine, not sure how true that is, but ill find out.

I'll keep everyone posted just incase someone else is having these problems.

 

[bcart01v]

Quick update, and hopefully someone can give me an answer.

A few times I've heard this hum that comes from the rear of the engine, it sounds electronical, and it almost sounds like the windshield washer motor. It kicks on for a few seconds, then goes away, now since my car hasn't been running to well I couldn't tell if it was effecting the drive at all, but today pulling up to a stop light, the hum started for maybe 5 seconds, and the second it stopped my idle was erratic, and it was trying to die. I put it in park, gave it some gas and all is well.

What could this mysterious hum be? It rarely happens and I can never get it to do it again. Its hard to search to.

Help!!

 

[bcart01v]

another update.

Well, the humming/whirl sound has only happened once since last reported, it happened turning into my neighborhood, going about 15mph, as soon as I gave it gas it stopped. I'm kinda thinking its the fuel pressure regulator, being as I've never heard this sound until I plugged the vac line back in. I also haven't drove it since, being as im tired of worrying If I'll make it home or not anymore.

Tommorow i start my vacation, which means more time to work on car. First things will be the intake gaskets and go from there. At this point im praying anything will work.

 

[bcart01v]

Guys...

right now im in the middle of replaceing the intake gasket, and i think ive found my problem.


There is none....


I just took the top half of it off, and whoever worked on this before, never put a gasket back on the engine, or on the throtle body, or between the IAC valve, and they replaced the EGR vac lines with fuel lines that were way to big...

Call it a hunch, but i think im on to something here..

 

[bcart01v]

Alright, im gonna need a second opinion here.

After replacing the upper intake gaskets this is what i've gathered.

The engine was torn apart before, the lower intake gasket has been replaced recently it look pretty new, but the upper gasket was missing. Im missing the VAC line running to the Fuel pressure regulator, and the DPFE sensor was new along with the vac lines running to the EGR, they were also new.

I Havent pulled any codes, and i would say that im looseing power, but im kinda not.

I can press on the gas pedal, and it wont respond instantly, but it will get up there. Slowly but surely the RPM Guage moves up there, but it seams my RPM guage moves faster than my speed.

Additionally i noticed that i was low on oil, added some STP to it and put TransX into the transmission (Which needs flushed obviously..)

My only question, what would someone gain by removing the vac lines to the Fuel pressure regulator? wouldnt it run rich? cause im not.. before it said i was running lean and i assumed i was just getting to much air.

After this im waiting till tax returns and taking it to a shop. I've spent every day off for the past 4 weeks messing with this, not getting anything else done.

EDIT:

Well check engine lights back on, Fuel system to lean bank 1 and bank 2. Seams like an entire waste of time.
However, i did fix the tempature problem. Whoever installed the last thermostat (which was new), installed it backwards, after putting the new one it, it warms up nicely.

I think im going to just be one of those people with a check engine light constantly on.