When I had to have one of my trucks (my Nissan) smogged in California, the only reason why they opened the hood was to troubleshoot the error code(s) that was causing my check engine light to remain lit. Turned out to be a faulty in-tank fuel temperature sensor. Other than that particular time, they never opened the hood, they just hooked it up to the machine and tested that truck. They never opened the hood on my '86 Ranger 2.0L 4-banger when I had it tested, either. Maybe some inspection stations are not as strict as others *shrug* Glad to hear you got your problem(s) fixed, though, Canadian!

 

Well I bet that was at a regular smog place, they keep making me go to a test only center, where they are the Smog *****! I look at my smog paper and it says my truck has a high emitter profile.....

 

This is a great thread... But mine has the opposite problem.

It started out just like yours, but did it all the time... I started on the exact same route, replacing everything, tracing wires, testing sensors.... Noting worked.

One day, while warming it up, I heard a "CLICK!" down by the computer... The motor picked up RPM's, and I had power again!! Don't know what relay clicks, but you may want to look into that area.

Now everymorning, I have to start it for 1 minute, then the click, and it will idle.

I just bout everything for the duraspark conversion... Tired of messing with it.

Sorry for the hi-jack.

 

seriously tho! I want to do the duraspark conversion so bad, but I know they will make me toss my truck even if its getting better mpg! It makes me sick! anyways today, after installing my MAP sensor yesterday, I went to start my truck after letting it sit in the cold. Guess what! the problem came back! my truck runs better but still I am about to pull this ****e off and burn it just to make me feel better!

 

Yes, BIIs are "gross polluters", although the last emissions test I had done on mine in Washington (state) before we moved, it passed with flying colors, but there were a couple of the numbers that were high, but I believe it was because the BII is OBD-I and the new requirements are OBD-II. I know for a fact that it's that way in California, and has been ever since about the same time that the first OBD-II equippped cars and trucks started rolling off the assembly lines. We don't have any emissions testing here, that I am aware of... but I could be wrong. I'm still debating changing over all of my vehicle registrations, but may eventually do that. Anyhow, back to the topic... I'm wondering if there's some sort of vacuum leak or something contributing to the problem. I know the fuel-injected 2.9s have the IAC that tend to cause a similar problem, but this is weird. I'd still consider checking into the choke adjustment(s) and idle adjustments, etc.

 

well I have a hunch, My ICS motor on my carb. hasnt been working for a while. so im guessing my truck goes to switch modes to let it control the idle and since its not working it begins to stall. just and idea.

 

Thought I should keep you all posted on where I am at!!!
It has been a long road but I have made progress.

After the posting on the feedback solenoid which I had replaced I had a day where the vehicle wouldn't run at all unless the pedal was almost to the floor. I left work (16 miles from home) and my gas tank was 3/4 full, when I got home it was 3/8 full and the whole way all I could smell was gas.
The next day I pulled the carb and found the feedback solenoid flooded with fuel, it had leaked out and into the solenoid itself. I could not find a new one so I went over to a buddies junk yard and after a long search found a carb which I pulled the solenoid off. After cleaning it up (carb had been in yard a few years) I put it in. The engine ran but was still not what it should be. After scouring every parts store (Ford included) I found one available in the internet and had it shipped. I put that in last weekend.
I took the old one apart and found the solenoid sticking from wear. There was a small spring in it that was broke thus allowing the solenoid to stay open when it supposed to close.
This is a contraction from hell. It looks like fuel could leak into the solenoid compartment when the rubber flapper is open??? Anyone know anything about this?? If it does it gets scoured up and dumped into the air horn as the cavity is open to the air horn, bums must have known this little thing would fail and wanted to be sure the fuel went into the engine????

During the process of this all I went to readjust the choke and found another good item after hitting the choke plate with a power jumper on the heater to see how it opened and closed. When I hit the plate the choke jumped closed and stayed there. Repeated tapping on the plate got the plate to kind of pop into position. I removed the screws and found a problem. The replacement choke heater had two slots in the coil loop that catches the arm that opens and closes the plate in the air horn. The slots went about 3/4 of the way into the ring. The arm was just long enough to catch the loop but barely. Tapping on the plate would cause the arm to jump out of the loop in heater coi and the plate could slip by. The choke heater evidently was either the wrong model or the unit is designed for multiple applications. I looked for a fix. I took a piece of 1/8" metal brake line and using a tubing cutter cut a small piece the width of the metal heater coil. It was a perfect fit and since it is round moves free when the arm is engaged in the coil loop. I reinstalled the parts and tapping on the plate does not allow the arm to jump out of the loop. I readjsted the choke and fired her up.
The vehicle has not missed a beat all week. I have not had a wet day but it has been 10 below all week and the engine is performing as it should.
I may be back here crying on the next wet day but one thing for sure the items I found were definately problems that needed repair.
I'm not complaining, the engine has 254,000 on it and if I didn't love this thing so much may have given up on it sooner.
I have not had a car payment since 1990 because of this vehicle so I will keep at it.

Heres another question someone may know the answer to.
How does the ECM control the choke heater realy. Most Fords choke heaters are connecter to the stator on the alternator. When the alternator is making power (aka engine is running) the heater heats up and opens the choke.
On the Bronco II there is a relay controlled by the ECM. A contact has power off the alternator on one side and the feed to the heater on the other. The ECM turns the relay on which in turn warms the choke.
With a meter connected to the wire at the heater the meter pulses over and over sending 12 volts to the heater.
Does this sound like a normal thing??
I have to get a few minutes qand connect the meter to the unit when the engine is up to temp and see if the pulsing is still there. I would expect that the relat which is a transistor circuit would leave the heater on to keep the choke open???

 

Forgot to mention the code 31 issue.
No matter what I did the code 31 was always on the scanner.
While adjusting the carb I noticed if the idle was set a little higher then normal the scanner would generate the code 31. I came by this while setting the throlle plates. My throttle position sensor is adjustable. I like my engine to idle at 900-1000 rpm (my thing) I had adjusted the sensor so this rpm is considered closed throttle position. There is a couple way to do this. One method is to drill the holes in the plates a little larger. You should go up one drill size, (hopefully you have all the drill sizes #drills and lettered drill included in your set) at a time until you get the desired rpm. You can also set the throttle plates so they yield the correct setting. You then adjust the throttle position sensor for the recommened voltage the ECM should see for idle. I used the adjust the throttle plates method. It appears that I was off just a bit on the setpoint. Being off somehow generates the code 31.
The ECM looks at the voltage reference according to the manual as what the base setting should be when comparing the position of the EGR valve position sensor. Correct me if I am wrong?? I was always led to believe that meant the ECM was looking at the 5 volt reference signal of the ECM. It may be that the ECM is looking at the difference in reference voltage of the throttle position sensor and since that voltage was a little below the normal the EGR code 31 states that the voltage seen at the EGR position sensor is above the reference voltage indicating an open EGR valve when in fact it was just this setting being off??
I reset the idle where I wanted it and made the adjustment on the voltage of the throttle position sensor, this is a tricky thing to do as if you are off on the high side the ECM generates a code on the throttle position sensor.
I got it all set and the code went away.
I'd have been better off drilling the holes. The settings on the TPS would be normal. I just don't care for the lower rpm of the engine.

If anyone has any feedback on this I am open to anyones thoughts?

 

as far as the stalling Issue goes, I have been dealing with this problem since i moved my truck to a colder climate. The other day I took my whole distributer out and took it apart and cleaned it. i noticed that my dist. pickup was looking a little shot where it connected to the TFI module. I cleaned it up as best I could and my truck ran great the next day, not running then decided to stall. the next day after letting my truck sit in the moist rain, it did it again. i bought a new pickup today and am going to install it and see if this will fix some problems.

 

I believe the ECM controls the relay for the choke by pulsing a small current to it till it opens. I do not believe there is a trigger to turn it off or on, it just does this all the time.

I re wired mine to the stator on the alternator... works great!

I hate to say it man, but your starting down that "Replace every sensor" road. Nip it in the bud and Duraspark that baby. Unless you still have to put it through inspection?

I live in Oregon, so once your vehicle turns 20, you no longer have to get it smogged. Plus I live outside of the city limits, so it's not required anyway.

I saw another post here about your code 31, it seemed to point to a faulty EGR sensor.
They replaced it, and got another bad one.

 

Glad to hear you got the problem pretty much bagged and tagged, Nightstalker! Okay, if I remember right, the ECM pulses a signal to the choke heater until it's warmed up, and I believe it does this via reading the ECT sensor. I could be wrong, but I believe it's the same principle as how the EFI 2.9 works with the IAC.

Canadian, you may have to invest some time and all as Nightstalker did to fix it completely. I do know that especially Ford / Motorcraft / Autolite distributors / distributor caps have a tendency to NOT like damp / wetness. Sometimes you have to go the extra steps to seal things up so water and whatnot doesn't affect things.

EGR's are nothing but a pain in the a**. I have no idea what any car manufacturer that had them was thinking. For one, you don't want hot air going into your intake. Period. It messes with power, economy, and... EMISSIONS. If vehicles had the right ignition power-wise, cooler intake temperatures, and all of the other things right... the engines would be more powerful and burn a lot cleaner. Just my silly opinion.

 

But that makes sense.

 

Canadianice
Heres something you may want to look at. While I was trying to find the problem with my Bronco a friend suggested that the distributor may have a hairline crack in it. He said his Uncle had an 85 Bronco II and after tons of futility on wet days he took it to a Ford garage (back when mechanics worked on these beasts without the help of a computer) the mechanic told him there had been a recall on distributors. Some of the distributors developed hair line cracks that when the distributor warmed up opened up allowing moisture into the distributor. Since the crack was on the bottom of the distributor the moisture hung around inside fouling the spark.
A good test would be to warm up the vehicle and then spray the whole distributor with silicone, a good silicone spray, then see if it helps. That may lead you to whether moisture is the problem.
I used to have an Escort the was finiky about moisture. It was the engine model that had the little vent in the distributor cap. I swear the reason for the vent is they knew this sucker was going to get moisture inside the dist. so they thougth ahead and added the vent on the top of the cap to allow it evaporate out. I changed the cap to one without the vent and used to spary the entire distributor with the silicone each time I changed the oil in the vehicle. I would take a rage with mineral spirits and clean the cap & distributor real good before reapplying the silicone. Never misfired again.
This little fix is a lot easier then trying to seal up the thing with some type of goo that doesn't come off real when if you have to work on the part.

 

Considering the amount of rust I saw under my distributor cap the last time I had it off.... this would not surprise me if I had a similar issue going on with my '87. If it weren't such a pain in the butt, I'd prefer to pull my distributor and rebuild or replace it. I'll probably end up waiting until I do an engine rebuild to mess with it, however, I may look into doing the silicone spray seal thing.

 

Do you just pull the cap and rotor and then spray silicone all over everything? And why silicone? What does it actually do?