Serious stalling!

[Bmwz389]

Hey guys,


It's been a while, but i can always trust this forum to help me out fast when I need it the most.

I have a 92 explorer 2 wheel drive (4.0).

Yesterday I was driving to get my hair cut and the exhaust fell off from where the c bolt tie down is after the rear of the muffler (the weld split at the resonator).

But that's not what I'm worried about, but figured I'd throw it in.

Today (about an hour and a half ago), I was at the store gettin a drink.

I got in the truck and started it up, it ran fine. I put it in reverse and gave it just over half throttle.

All of a sudden this thing is feels like it's missing to all hell. It's sputtering like crazy, about to stall out. When im driving the tach is bouncing like crazy.

I pressed it down halfway while driving, and everytime it'll downshift, and increase RPM for about 4-5 seconds, and then it will start cutting out again.

Like it's misfiring or havin a fuel cut out.

Any idea what I should be looking for? It ran fine all week, and ran fine after the exhaust fell off.

Thanks i advance guys! I'm hopin to hear soon as this is my only ride right now...

- Brandon

 

[Armyguydan]

Sounds like it could be a clogged fuel filter 2 me. As a side not I was having stalling problems and found my air intake tube from the air box to the intake was badly cracked and was sucking in ice cold air. After I replaced it it's running fine. Good luck and I hope I helped.

 

[MrShorty]

Probably the first thing I'd do if I thought it was "havin a fuel cut out" would be to put a fuel pressure gauge on it and see if the pressure was dropping off when it stumbled.

I've seen similar symptoms come from having a vacuum line come off (lost the line to the PCV valve once on mine). I would suggest making sure all the vacuum lines are hooked up.

I might pull codes from the computer -- you never know if there will be anything useful in the trouble codes or not, and it only takes 5 minutes to run each test.

 

[Blacksheep Josh]

As mentioned before, definitely check fuel pressure and see what it's coming up. Also might want to check your spark plugs and make sure none of them are fouled to bad...

But do a fuel pressure check, and then replace the fuel filter if it seems clogged. Also check all your vacuum lines, especially where it's just capped off in the back, those tend to come off at times.

You can also clean your IAC and MAF sensors, if those get dirty sometimes it'll mess up the idle.

Also, when was the last time you changed your spark plugs?

 

[glfredrick]

Most common stuff I can think of below


Fuel pressure regulator? (pull off vacuum line, if filled with fuel, regulator is bad)

Ignition Module? (pull off and test at Autozone or other parts house)

Open EGR? (chunk of carbon holding it open) (test engine vacuum with a cheap vacuum guage -- if it is not above 18 at idle, you have a problem - unbolt and clean with carb cleaner)

Vacuum line? (first, visual, then if need be, use starting fluid -- VERY short burts in vicinity of vacuum lines, if engine revs up, you've found your leak -- WARNING -- DON'T HOSE DOWN THE ENGINE COMPARTMENT UNLESS YOU ALSO WANT TO REPLACE THE VEHICLE AND YOUR FACE!)

IAC? (Idle air, located on the top of the plenum, unbolt and clean with carb cleaner)

Plugged CAT? (have to remove to test - gets worse after long idle period, engine oil is burned in cat, plugging it up - can clean out after higher rpm run, but will plug again at idle)

 

[Bmwz389]

Hey guys!

Thanks for the fast replies everyone!

I wrote these all down on a list to check out.

Fuel filter: Don't know last time it was replaced
Intake tubing: bought from junk yard about 5 months ago, checked all, seemed ok.
FPR: Replaced about a year ago cause I was having a fuel smell.
Vacuum lines: will check all
Spark plugs: Probably around a year ago. don't have my log sheet to check the date.
IAC: cleaned 2 or so years ago.
MAF: cleaned about 6 months ago
EGR: never been touched lol
Ign Mod: Will look into it
Cat: was wanting to hollow it out but didn't know if it would throw a code...


We're gonna run outside and start overlooking the car, it's freezing out but I gotta get this done, it barely strarted this morning.

Thanks guys!

- Brandon

 

[Bmwz389]

Ok so this was completely stupid.

It turns out the intake tube from the box to the buttlerfly came loose and it was sucking air in past the MAFS.

I'm not sure how the hell this happened, maybe i didn't tighten it enough after installing the new alternator in it, and it came loose over time.

But what I don't get is I could have sworn it would run fine without the intake on.

I have no idea how we missed it last night out behind target when it was stalling. It must have been too dark to see it or something. No clue.

But thanks alot everyone! I can't believe it was that simple of a problem.

I do want to know if I can hollow the cat out, as it's quite old and it would sound better without it wouldn't it??

- Brandon

 

[gsx220]

as far as the cat if you get a sniff test for your inspection you probably wont pass with it hollowed not to mention being bad for the planet and all lol but i never ran a car on my gsx and didnt have an issue but that was turboed and stuff i think there is an o2 sensor after the cat so it might toss a code i think i read that before im not sure tho

 

[tigercat]

i did it to mine it sounds better 91-92 has one O2 sensor in front and 93-94 has two, one in front and one behind the cats so if you have a 91-92 you should do it, if you have 93-94 dont you will loose a lot of power.

 

[Bmwz389]

Ok that sounds good.

Im about to post a new topic on the exhaust now to get some more info, I figured it would make more sense to have an exhaust topic.


Thanks for all your help guys!
- Brandon

 

[glfredrick]

Before I hollowed out the cat on anything except a pure off-highway vehicle, I'd replace it with a new high flow unit.

I'm no tree hugger, but we need to be responsible people, and cats do a great job of reducing vehicle emmissions with no real penalty in horsepower or exhaust flow (until high flow/rpm racing scenarios at least).

I've used universal high flow cats from eBay sellers with great success. I'm even running one on my Ranger build once it goes together.
(Example -- no recommendation -- http://cgi.ebay.com/ebaymotors/Stai....c0.m245&_trkparms=72:543|65:12|39:1|240:1318 )

Ditto on the double O2 sensors. If the cat doesn't do its job (hollowed out) you will get a code. The work around here is to install a fake rear sensor (sends a signal to the computer as if the cat works) but for the reason above, I don't recommend that for highway use.