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My 89 5.8 Bronco failed California smog.

The test was done cold.

At 15 mph (1545 RPM) it measured 165 HC PPM (MAX 81) and 1310 NO PPM (MAX 690)

At 25 mph (1526 RPM) it measured 42 HC PPM (MAX 66) and 1161 NO PPM (MAX 592)

So far I have replaced:
Spark Plugs (correctly gapped)
Spark Plug Wires
Fuel Pressure Regulator
Air Filter
PCV
Crankcase Breather Filter
Gas Cap
Fuel Filter
Oil and Oil Filter
and I'm picking up a new Oxygen Sensor today.

The truck is significantly more powerful, in fact, better than it's been the entire time I have owned it for the last ten years. I always felt it had driven quite nicely, in a way I'm glad I had to get it smoged for the first time, however, I'm very concerned about failing the smog test again because I don't want the truck to be labeled a gross polluter. I'm new to the smog stuff, but I feel confident that it will pass the emissions test this time around.

My big concern is that: It passed the entire Emissions Control Systems Visual Inspection/Functional Check Results with the exception of the Ignition Timing. However, I don't think that the issue has anything to do with the timing, occasionally the throttle gets stuck, the peddle will behave normally but the RPM stays very high, 3500+, I can stomp the peddle and rev the engine up further, then release and the RPM drops back to normal. This condition happens after the warm up cycle, and usually occurs during driving conditions, but even after shifting to park it continues. After the truck has been driven around for half an hour or so the throttle isn't sticky anymore.

My scan code reader returned the errors.
12 RPM at idle out of range/high
21 ECT out of Self-Test range MAP/BARO out of Self-Test range.
33 EGR valve opening not detected.
44 Secondary Air Injection system Inoperative (right side).
70 ECM failure
77 Brief WOT not sensed during Self-Test / Operator error.

After the truck being fully warmed up with a half hour drive or so, I don't get any errors.

I'm suspicious of the EGR valve and it's sensor, but I don't see a lot of reason to replace them without a warmed up malfunction. Does anyone recognize my trucks situation or have some good suggestions to resolve the problem?
 

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Chillin on the Gulf Coast
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1,596 Posts
I have no personal experience with smog testing (I have only had vehicles registered in Louisiana in an area with no emissions restrictions), but you might try THIS thread to help with that though. As far as the throttle, pop the hood and remove the plastic cover over the throttle body and see what condition your throttle cable is in. I have seen many of them that had a piece of the tube inside the spring broken and causing the cable to bind in a partial throttle condition as you try and let off the gas.
 

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AKA: Butthead
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2,857 Posts
My 89 5.8 Bronco ...occasionally the throttle gets stuck, the peddle will
behave normally but the RPM stays very high, 3500+, I can stomp the
peddle and rev the engine up further, then release and the RPM drops
back to normal. This condition happens after the warm up cycle, and
usually occurs during driving conditions, but even after shifting to park it
continues. After the truck has been driven around for half an hour or so
the throttle isn't sticky anymore.

After the truck being fully warmed up with a half hour drive or so, I don't
get any errors. "The test was done cold." -Steve
The shops that make money off of getting it "to just pass" make a
big deal about the need to let the sucker idle while waiting in line...
don't shut it off and restart, let it get good n hot and stay that way.

Changing the oil is another one that was important, I was told (but
you done did that already).

IME you need to clean or replace your IAC to fix the fast idle trouble.
If yours is the take apart kind then take it apart and clean it like you
mean business. ;) Read the resistance of its coil too, had one that
was acting stupid because of the coil resistance was out of spec.

Here's Ryan's page with a picture of the "take apart kind ;)"...
http://fordfuelinjection.com/index.php?p=39

---------------------------

You say the pedal acts normally so this doesn't fit your situation
exactly, but... ;)
I found that two things can make the pedal sticky 1) cable routing
2) throttle plates sticking because they are jamming in their bores.

Cleaning the throttle body and oiling the mechanism with DuPont
Multi-Use (dumb name, good stuff) seems like it helped but that
wasn't the cure on mine. To adjust the throttle plate stop needs
a volt meter because it effects the TPS voltage tho. Instructions
for that procedure are here on FSB somewhere. ;)

Steve, swapping out the TPS while you're at it won't hurt either.
Rockauto used to sell Standard Motor Products stuff but not sure
what anymore. :/ SMP was the manufacturer of a lot of stuff for
the auto industry and labeled it whatever the buyer wanted like...
"Motorcraft" for example. ;)

Alvin in AZ
 

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AKA: Butthead
Joined
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2,857 Posts
As far as the throttle, pop the hood and remove the plastic cover over the
throttle body and see what condition your throttle cable is in. I have seen
many of them that had a piece of the tube inside the spring broken and
causing the cable to bind in a partial throttle condition as you try and let off
the gas.
x2 :)

But not sure it applies since Steve claims the pedal is acting right.

The plastic sleeve wasn't broken on the '91 F150 I inherited but
it broke the instant I messed with it! :/ Since then, I haven't seen
one that wasn't broken. ...Ford dropped the ball on that part. :/

Alvin in AZ
 

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Chillin on the Gulf Coast
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1,596 Posts
I have an autozone cable that I bought with a lifetime warranty, so if I ever have an issue with it I can remove it and replace it easily.
 

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Premium Member
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23,549 Posts
Test done cold.

Well the smog tests are supposed to be done on a hot and thoroughly heated engine. a engine thats cold is running rich and trying to heat up to operating temp.
 

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Premium Member
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9,990 Posts
cajunrebel: Thank you Brother that's the place to start......:rockon

The use of 91% Isopropyl Rubbing Alcohol is a big part of the formula for passing ANY state smog test. My 86 was deemed a Gross Polluter in 2007 so CA has a consumer assistance program if you can qualify financially with low income of up to $500.00 FREE in the form of an authorized letter mailed to you to be used at any "state" approved" Gold Seal smog station thru Bureau of Automotive Repair to fix any smog problem and if you still have a problem, you can then go to a DMV Referee for a fee and get registration and tags for 2 years so you can fix the problem.
In 2008 I swapped in a new 302 EFI long block and was the FSB lab rat in 2009 and PASSED then again this past Sept lowering my timing to 8* BTDC, using the alcohol and PASSED agian at Test Only facility with flying colors first time around, using a timing light they either didn't notice my timing or don't understand how to use them....lol lol.....so follow ALL suggestions as it applies to your BKO. and by all means when you go for a smog test, any questions they ask PLAY DUMB, I DON"T KNOW OR I DON"T WORK ON THE VEHICLE........savvy? :doh0715:

There is a Ford Racing Performance Parts "idle setting procedure" Instruction Sheet (Techline (800) FORD788) steps 1-9 on How To adjust idle by disconnecting the IAC using the throttle body idle stop screw, drilling out the mounting screw holes on a newer "plug & play" TPS so you can adjust it for voltage setting.

In the past the ideal setting was thought to be .93-.97 volts or just under 1 volt but recently posted information regarding this appears the setting should be between .55v-.75 volts.

Posted by FSB member Jermil01 recently:

Wanted to update this thread based on some TPS adjustment information I got from one of my tuning sites. This goes against the conventional wisdom of setting the TPS closer to .95 range. Thoughts??

Regarding any ECU controlled function (and idling conditions in particular), before any strategy based adjustment can be made by a computer controlled system, it must first run somewhat normally in a default and OL mode.

To do this with a FORD you must first follow a few rules.

You must keep the TPS input above the deadband area and below the "tip in" area. On a FORD this equates to below approximately 0.9V and above 0.45. Anything above 0.90V the ECU thinks the throttle is starting to open. This brings into affect possible dashpot and fuel cut strategies which can turn one grey real fast. Below approx 0.40-0.45V the system suspects an incorrect input and substitutes a default figure.

So first off, the TPS should be set to around 0.55-0.75V. You can also disconnect the IAC then disconnect the battery for 15-20 minutes, reconnect and the computer should default back to factory settings.

Good Luck ~ :thumbup
 

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AKA: Butthead
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2,857 Posts
{Ford sez} the TPS should be set to around 0.55-0.75V.
Cool post KJ! :)

That "just below 1.0v" setting has been bothering me ever
since I first read it because of what Ford sez about it.

I'm going the double check mine, but I believe I've got it at
.85v right now anyway.

Alvin in AZ
 
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