93 Explorer Failed Smog NO
Thread Starter
|
Senior User
Joined: Dec 2000
Posts: 100
Likes: 0
From: Sacramento, CA
93 Explorer Failed Smog NO
My 4.0 V-6 Failed smog test in California, NO(ppm) )oxides of nitrogen were high.
Did ok on 15mph test but failed 25mph test ( max is 508 and I had 672).
Smog tech said try O2 sensor and run a can of injector cleaner thru it. He said the EGR valve is also a potential culprit, but he said this car doesn't have one.
Any geniuses out there that know smog stuff??
No check engine light or other abnormalities.
The only odd thing is that I run the car with the octane shorting bar removed (I replaced it for the test) to keep the engine from pinging.
What else besides the O2 sensors should I look at?
Thanks - Chris in Sacramento
Did ok on 15mph test but failed 25mph test ( max is 508 and I had 672).
Smog tech said try O2 sensor and run a can of injector cleaner thru it. He said the EGR valve is also a potential culprit, but he said this car doesn't have one.
Any geniuses out there that know smog stuff??
No check engine light or other abnormalities.
The only odd thing is that I run the car with the octane shorting bar removed (I replaced it for the test) to keep the engine from pinging.
What else besides the O2 sensors should I look at?
Thanks - Chris in Sacramento
Postmaster
Joined: Dec 2001
Posts: 3,742
Likes: 2
From: UT
93 Explorer Failed Smog NO
I'm not an expert on emmissions, but that ping issue suggests that something isn't right. It's actually common on this engine. Commonly caused by a dirty MAS or a vaccum leak, usually around the lower intake manifold. Don't know that it will resolve everything, but it can't hurt.
Thread Starter
|
Senior User
Joined: Dec 2000
Posts: 100
Likes: 0
From: Sacramento, CA
93 Explorer Failed Smog NO
Checked KOEO and engine running codes - nothing showed up just 111 which is OK.
I'll look into the MAF.
Isn't there an easy way to check for vacuum leaks ? Seems like I heard of a procedure somewhere...
I'll look into the MAF.
Isn't there an easy way to check for vacuum leaks ? Seems like I heard of a procedure somewhere...
Postmaster
Joined: Jan 2003
Posts: 4,417
Likes: 3
From: Durham, NC
93 Explorer Failed Smog NO
I agree, the lower intake getting loose is common. To check for
a vacuum leak, try spraying some carb cleaner between the
intake & heads while it is idling, and you will see a difference
in the idle speed if it is leaking.
a vacuum leak, try spraying some carb cleaner between the
intake & heads while it is idling, and you will see a difference
in the idle speed if it is leaking.
New User
Joined: Jun 2002
Posts: 12
Likes: 0
93 Explorer Failed Smog NO
Been there on the pinging. There is an Explorer Maintenance site with an "Engine pinging" page, which EXACTLY nailed my pinging problem ('93 V6 pushrod engine):
http://www.glue.umd.edu/~singletn/web/pages/ping.html
The sparkplug #5 thing was for real (sparkplug #5 is the middle plug on the driver's side)
I fixed the problem for a while by re-torqueing the intake manifold bolts, but I eventually ended up replacing the lower intake manifold gasket.
Your vehicle, if it was originally manufacured for the California market, might be one of the very few '93 Explorers which does not have the pushrod engine, so you'll have to check for engine code "X" (the 8th character in your VIN).
http://www.glue.umd.edu/~singletn/web/pages/ping.html
The sparkplug #5 thing was for real (sparkplug #5 is the middle plug on the driver's side)
I fixed the problem for a while by re-torqueing the intake manifold bolts, but I eventually ended up replacing the lower intake manifold gasket.
Your vehicle, if it was originally manufacured for the California market, might be one of the very few '93 Explorers which does not have the pushrod engine, so you'll have to check for engine code "X" (the 8th character in your VIN).
Thread Starter
|
Senior User
Joined: Dec 2000
Posts: 100
Likes: 0
From: Sacramento, CA
93 Explorer Failed Smog NO
I'll do the carb cleaner thing for the leaks; and torque the intake manifold. I know there's almost a cult following on the pinging problem , I'll check out that webpage, thanks. Although we bought the car used in Sacramento, it is not a CA car for smog requirements (originally registered in Idaho).
Keep those ideas coming- I'll report on the results.
Keep those ideas coming- I'll report on the results.
Trending Topics
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
93 Explorer Failed Smog NO
I posted the TSB concerning pinging in the Ranger forum in about the middle of Feb; it applies to the Explorer too. Note that the TSB is anly applicable to the 4.0L engine. Someone has also used Marvel Mystery Oil to eliminate the last bit of knock, that was also posted in the Ranger forum within the last week.
Running the fuel down to about 5 gals and adding a pint of naptha is another trick to make em pass emissions. That naptha causes the converter to heat up more and become more effective. Just fill the tank back up after the test. It's being done on a regular basis in my area; seems the tail pipe sniffer doesnt see the naptha.
Running the fuel down to about 5 gals and adding a pint of naptha is another trick to make em pass emissions. That naptha causes the converter to heat up more and become more effective. Just fill the tank back up after the test. It's being done on a regular basis in my area; seems the tail pipe sniffer doesnt see the naptha.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Thread Starter
|
Senior User
Joined: Dec 2000
Posts: 100
Likes: 0
From: Sacramento, CA
93 Explorer Failed Smog NO
That's a great web page; a compilation of posts for each topic on maintenance of Explorers-(probably work for Rangers to).
I cleaned the MAF (per one of the articles on the webpage) and will get to the intake manifold next.
Cowboy- whats the date and name of your TSB post on pinging?
I cleaned the MAF (per one of the articles on the webpage) and will get to the intake manifold next.
Cowboy- whats the date and name of your TSB post on pinging?
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
93 Explorer Failed Smog NO
Article # 01-19-7, dated 10/1/01. Title is "Engine - Carbon Knock on acceleration". I found this in the Alldata website, a pay for info service. However, they were kind enough to provide a sample of their product which happened to be for the 93 Ranger. I provided the URL in my posting in the Ranger forum, along with the verbage of the TSB.
Thread Starter
|
Senior User
Joined: Dec 2000
Posts: 100
Likes: 0
From: Sacramento, CA
93 Explorer Failed Smog NO
Checked #5 plug - beautiful tan-grey tip with no build-up. Gap was too much, bent it back down to .054.
Couldn't figure out how to get to the intake manifold bolts- hidden behind the other accessories; just two or three accessible.
Since I changed the O2 sensors (2) and cleaned the MAF and replaced the octane bar, and ran a can of "emissions cure" in the gas (premium) = no more pinging. Hope it stays that way with regular gas too.
Heading out now for the smog test place for a recheck- cross your fingers and hope...
More later...
Couldn't figure out how to get to the intake manifold bolts- hidden behind the other accessories; just two or three accessible.
Since I changed the O2 sensors (2) and cleaned the MAF and replaced the octane bar, and ran a can of "emissions cure" in the gas (premium) = no more pinging. Hope it stays that way with regular gas too.
Heading out now for the smog test place for a recheck- cross your fingers and hope...
More later...
New User
Joined: Jun 2002
Posts: 12
Likes: 0
93 Explorer Failed Smog NO
Your clean sparkplug means that you don't have motor oil or coolant being sucked into the intake (at least on the #5 side of the engine), so you might not have a loose lower intake manifold...
But, the good news is, if you'll really crawl up in there and look, the manifold bolts can all be torqued without removing the upper manifold. They are accessible between the "legs" of the upper manifold. There are 2 studs at opposite corners of the manifold that are a bit difficult, but the toughest one (in the front, I forget which side) I was able to tighten using a crow's foot wrench.
Put a socket on one of the more accessible ones - mine were so loose that they turned without any resistance whatsoever, by hand, without using a ratchet, just an extension on a socket...
But, the good news is, if you'll really crawl up in there and look, the manifold bolts can all be torqued without removing the upper manifold. They are accessible between the "legs" of the upper manifold. There are 2 studs at opposite corners of the manifold that are a bit difficult, but the toughest one (in the front, I forget which side) I was able to tighten using a crow's foot wrench.
Put a socket on one of the more accessible ones - mine were so loose that they turned without any resistance whatsoever, by hand, without using a ratchet, just an extension on a socket...
Thread Starter
|
Senior User
Joined: Dec 2000
Posts: 100
Likes: 0
From: Sacramento, CA
93 Explorer Failed Smog NO
That's loose!!
I put a torque wrench on the two I could get to easily and they were close to what they should be ( ~ 200 in/lbs / 18 Ft.lbs)
PASSED THE SMOG!! (barely)
All the numbers showed improvement from the failed test so I guess the 02 sensors were the main culprit. As far as I know they are original (123,000 mi).
I'll check out getting to the remaining manifold bolts.
Thanks for all the suggestions guys...
I put a torque wrench on the two I could get to easily and they were close to what they should be ( ~ 200 in/lbs / 18 Ft.lbs)
PASSED THE SMOG!! (barely)
All the numbers showed improvement from the failed test so I guess the 02 sensors were the main culprit. As far as I know they are original (123,000 mi).
I'll check out getting to the remaining manifold bolts.
Thanks for all the suggestions guys...
Thread
Thread Starter
Forum
Replies
Last Post
QuadVan
1968-Present E-Series Van/Cutaway/Chassis
4
Dec 18, 2013 06:46 PM
rwsam
1978 - 1996 Big Bronco
10
Jan 6, 2003 11:59 PM