1991 Ford F-150 Truck Failed Emissions

It has a little over 482,000 according to my odometer! But do you know anything about why the hydrocarbons are so high in idle so I can get it to pass?

I didn't until I busted out my haynes manual for my broke down car. That is another story. I don't have a compression gauge and that's a problem if they are expensive. I know I have a valve cover leak on the drivers side that's pretty bad and I'm going to try to tighten it down in the morning. I actually bought new valve cover gaskets but now that I have to drive the truck everyday I don't have enough time to take all that intake apart. Am I correct that there are three oxygen sensors on the truck and they all are the same? I was thinking I could get a sensor and try it in each one to see if it works? Then hopefully return it if it's not my problem.

Hi Joe,

I called autozone this morning and it's 38 bucks to rent a gauge so I am going to go get it and a sensor this weekend. Hopefully the sensor works:) I'm thinking if the compression is bad it's probably the valves because of the oil leak. Wish me luck and thanks!

Joyce

Hi Joe,

I tightened up the valve cover, replaced the O2 sensor and dropped sum lucas in the tank. I did not do a compression test for the shear fact that even if the compression has gotten weak there is nothing I am able to do about it at this time. Valve jobs are not within my capabilities when I have to drive it every day. I am going to attempt one final thing and that is the EGR because it was another code that showed up. Wish me luck and thanks for everything.

Joyce

Joe,

Is there anything in particular I should use to clean them out? Someone told me rubbing alcohol. Is that correct? My engine has some surging, so I'm hoping cleaning/replacing the egr is what is needed. I also have two skinny little intake lines (one red, one black) that have been cut off but are supposed to go to a "can" on the passenger side. Could this be a possibility for the truck failing emissions? I'm racking my brain trying to find a solution. As always any help is appreciated.

Thanks,
Joyce

Hi Joe,
It's the damndest thing but I passed emissions today! Don't get me wrong I'm grateful but if I knew how I did it then I could correct what is still wrong. So let me start from the beginning and maybe you can help me! I took the truck to emissions the first time and my loaded hydrocarbons were 115/220 and my hydrocarbons in idle were 1235/220. My CO in idle was.44/1.20 and loaded was.03/1.20. I replaced the water pump, plugs and wires, o2 sensor, cap and rotor. I also ran a 3-step fuel/intake system cleaner threw it yesterday foregoing the egr until I had it put on a diagnostic, and sprayed a little intake cleaner in the egr. By the way, when they ran it on the obd 1 diagnostic the only code they pulled was 67 and not an emisssions related code. Today I replaced to skinny vacumn lines going to the charcoal filter and had ran good gas in it for a couple of days.

Anyhow, this is what I would like to know. Today when they tested it my hydrocarbons in idle were 166/220 but my hydrocarbons loaded were 219/220. What is going on? I'm thinking the hoses were cut to pass hydrocarbons in idle once upon a time but why are they barely passing loaded now? I am going to do my homework to the best of my ability but any foresight would be helpful. Emissions will happen again!

Thanks,
Joyce

Anyhow, this is my

Joe,
I'm glad all my hard work was not in vain but I am concerned about the HC's still being so high under load because I barely made it. I did some checking and came up with this list of possible causes:

Elevated HC readings during acceleration indicate ignition misfire under load. The causes could be:

Defective knock sensor;

Weak ignition coil(s);

Excessive resistance in spark plug wires;

Arcing inside the distributor cap;

Worn, fouled or incorrectly gapped spark plugs;

Over-advanced ignition timing; or

Lean air/fuel mixture.

If you have anything to add please let me know.

Joyce

Joe,
I haven't noticed any misfire but what I have noticed is the timing does seem really high. I also noticed that I need a fan clutch because the fan is moving real slow. I need a new drive belt because it's got a bunch of little cracks and it bogs down when I get on the gas. I'm thinking fuel filters because I've run a ton of injector cleaner threw it and hoping it's not the pump. The motor seems to jump around a lot too, so I am going to check the mounts. I'm going to try to work on the fan and serpentine this weekend but I have a lot to do before Easter.

Happy Easter,
Joyce

Hi Joe,
Hope your Easter was good. I went today and bought the fan clutch for the truck but I'm not going to mess with it until I'm off on Saturday. I bought a truck for parts this past weekend but the motor was different and so was the clutch. I got lots of other great parts I need to put on though! Anyhow, I've been reading up on the fan clutch and a lot of people have said that the rental crap to get it off at Autozone is junk. So if you have any great ideas to make my life easier I would be happy. Also, if you have a recommendation on a reasonable sized compressor to run air tools that would be great because my elbows get to killing me:)

Thanks,
Joyce

You know what they say about he who laughs last! Necessity is the mother of invention and I'm not laughing if it works! I'm going to look into a small compressor like what you have because it will definitely make my life easier. I will let you know how it goes Saturday and thanks!

Joyce