93 Explorer runs too lean.
Thread Starter
|
Freshman User
Joined: Aug 2004
Posts: 26
Likes: 0
93 Explorer runs too lean.
I thought I would start a new thread since this is less about reading codes and more about how to fix at this point.
The story so far: 93 Explorer. Idles rough, dies most of time with a big gasp. Hard crank to start. Car at stop sign will settle to about 700rpm...sit...jump down to 500rpm, go back up to 700rpm...fight for its life. and then finally die. Putting it in Neutral can sometimes save me from dying.
Replaced: MAS Sensor, IAS sensor. Brand new. No effect on problem.
Sprayed WD40 around gaskets and EGR to see if idle "picked up" for vacummn leak. Got nuttin.
error codes:
172 - HEGO sensor circuit indicates system lean (right side)
138 - HEGO sensor circuit indicates system lean (left side)
What is my next step before I give up and buy my neighbors used Grand Cherokee?
The story so far: 93 Explorer. Idles rough, dies most of time with a big gasp. Hard crank to start. Car at stop sign will settle to about 700rpm...sit...jump down to 500rpm, go back up to 700rpm...fight for its life. and then finally die. Putting it in Neutral can sometimes save me from dying.
Replaced: MAS Sensor, IAS sensor. Brand new. No effect on problem.
Sprayed WD40 around gaskets and EGR to see if idle "picked up" for vacummn leak. Got nuttin.
error codes:
172 - HEGO sensor circuit indicates system lean (right side)
138 - HEGO sensor circuit indicates system lean (left side)
What is my next step before I give up and buy my neighbors used Grand Cherokee?
Last edited by scatpack; Aug 8, 2004 at 01:20 PM.
Elder User
Joined: Aug 2001
Posts: 942
Likes: 0
From: South Texas
1. Verify fuel pressure regulator is within specs. 35(+/- 5) PSI with vacuum line connected; 40 (+/- 5) PSI vacuum disconnected.
2. Pull all vacuum lines at the tree, plug them off, and see if idle improves. If so, find out where the leak is and fix it (look closely at the power brake booster & cruise control unit).
3. Double check EGR valve (if equipped) for a stuck open EGR system
4. If 1 and 2 fail to resolve the issue, pull the intake and replace the lower intake gaskets.
Bottom line is you either do not have enough fuel getting in, or excess air getting in. Either one of the two (or a combination of both) will cause the codes you gave. Of course, I assume you have checked out both EGO sensors and the associated wiring harnesses. I think the WD40 try was a waste of time and proved nothing.
Dialtone
2. Pull all vacuum lines at the tree, plug them off, and see if idle improves. If so, find out where the leak is and fix it (look closely at the power brake booster & cruise control unit).
3. Double check EGR valve (if equipped) for a stuck open EGR system
4. If 1 and 2 fail to resolve the issue, pull the intake and replace the lower intake gaskets.
Bottom line is you either do not have enough fuel getting in, or excess air getting in. Either one of the two (or a combination of both) will cause the codes you gave. Of course, I assume you have checked out both EGO sensors and the associated wiring harnesses. I think the WD40 try was a waste of time and proved nothing.
Dialtone
Thread Starter
|
Freshman User
Joined: Aug 2004
Posts: 26
Likes: 0
Originally Posted by Dialtone
1. Verify fuel pressure regulator is within specs. 35(+/- 5) PSI with vacuum line connected; 40 (+/- 5) PSI vacuum disconnected.
Trending Topics
Postmaster
Joined: Dec 2001
Posts: 3,742
Likes: 2
From: UT
Get a fuel pressure gauge.
Attach to fuel rail at Schrader valve (looks like a tire valve) on the passenger side of the fuel rail.
Turn the key on, ground fuel pump test lead in self-test connector. With the pump running, fuel pressure should be as noted above (40 +/- 5)
Unground the test lead to shut off the pump. Fuel pressure should remain within a few pounds of the initial reading for several minutes.
Start the engine. Fuel pressure should drop (if vacuum line is still connected) but stay above 32 psig.
Increase engine speed. fuel pressure should stay within a pound or two of the value at idle.
That's what it should do. And any good manual will have this procedure in it along with the diagnostic steps to take when a portion of the test fails.
Attach to fuel rail at Schrader valve (looks like a tire valve) on the passenger side of the fuel rail.
Turn the key on, ground fuel pump test lead in self-test connector. With the pump running, fuel pressure should be as noted above (40 +/- 5)
Unground the test lead to shut off the pump. Fuel pressure should remain within a few pounds of the initial reading for several minutes.
Start the engine. Fuel pressure should drop (if vacuum line is still connected) but stay above 32 psig.
Increase engine speed. fuel pressure should stay within a pound or two of the value at idle.
That's what it should do. And any good manual will have this procedure in it along with the diagnostic steps to take when a portion of the test fails.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Posting Guru
Joined: Apr 2003
Posts: 1,085
Likes: 0
From: West Chester PA
Do a search in this forum for the IAC valve. I recall that someone posted a thread here - might even be a sticky - about how to test it. The problem with the idle seems to me like the IAC valve could be at least part of the problem...
Good luck.
Edit - Yep. It's a sticky. Check the first thread in this forum. All you need to test is a voltmeter....If this isn't your problem, it looks like it will only cost you a few minutes...
Good luck.
Edit - Yep. It's a sticky. Check the first thread in this forum. All you need to test is a voltmeter....If this isn't your problem, it looks like it will only cost you a few minutes...
Last edited by maa139; Aug 9, 2004 at 07:42 PM.
Thread Starter
|
Freshman User
Joined: Aug 2004
Posts: 26
Likes: 0
Ranger,
Ah.. the ol' fuel filter. Theres another thread on here from me about my dreaded fuel filter. It doesnt come off becomes someone (Ford?) jammed the fuel filter so far into the fuel lines on both sides that it cannot be unlocked. My only option is to cut it off. Ive held back from that because I dont want to end up with 2 fuel lines with Fuel filter 'stems' that I cant remove.
So its staying on for now.
Ah.. the ol' fuel filter. Theres another thread on here from me about my dreaded fuel filter. It doesnt come off becomes someone (Ford?) jammed the fuel filter so far into the fuel lines on both sides that it cannot be unlocked. My only option is to cut it off. Ive held back from that because I dont want to end up with 2 fuel lines with Fuel filter 'stems' that I cant remove.
So its staying on for now.
Elder User
Joined: Feb 2004
Posts: 811
Likes: 0
That may very well be your problem. You can get the clips inside the line to repair the fuel lines from the ford dealer. Get them before you start. 
Part #'s should be, E9UZ-9B307-A, and or, E9UZ-9B307-B.
Part #'s should be, E9UZ-9B307-A, and or, E9UZ-9B307-B.
Last edited by ranger88a; Aug 10, 2004 at 09:30 AM.
Thread Starter
|
Freshman User
Joined: Aug 2004
Posts: 26
Likes: 0
FIXED!
It was 2 vacumm leaks. One at the T, one at where the hose for the air intake meets the manifold.
Fixed those, cleared codes. Im back in business!
Thank you everyone for your help!
(Still neglecting the gas filter....)
It was 2 vacumm leaks. One at the T, one at where the hose for the air intake meets the manifold.
Fixed those, cleared codes. Im back in business!
Thank you everyone for your help!
(Still neglecting the gas filter....)
Thread
Thread Starter
Forum
Replies
Last Post
handsomerob
1987 - 1996 F150 & Larger F-Series Trucks
12
Jan 23, 2018 01:01 AM
bigmacmondayf250
1987 - 1996 F150 & Larger F-Series Trucks
3
Jul 11, 2014 01:20 AM
SideWinder4.9l
1987 - 1996 F150 & Larger F-Series Trucks
7
Jul 30, 2011 08:29 PM
