Failed Emissions 1987 4.9 Liter F 150
#1
#2
#3
high hydrocarbons
I don't have the paperwork with me, that the state inspection center gave me. But I do remember high level of hydrocarbons were the issue. I believe it stated that my truck was above 500 and they wanted it down around 200 / 225. I showed papers to a friend that is pretty good with old rust buckets and he poked around. First thing he said was that he could hear a vacuum leak. Then he seem to think problem was EGR. He pulled vac line off EGR and said because engine didn't stop EGR was bad.
I did my own research with our public library's online auto manuals and Google videos / youtube videos. This much I learned: 3 types of EGRs.
1.Ported
2. positive back-pressure
3. negative back-pressure
They said determine what type you have and then they show you how to test with vacuum pump. They also said to make sure you don't have a vacuum leak some place else before focusing on EGR.
Another back yard mechanic told me a number of national auto parts retailers will plug into your trucks computer and tell you what trouble codes are coming up. This could be used to narrow down causes.
Finally I got prices for new EGR of 75-85 dollars.
I did my own research with our public library's online auto manuals and Google videos / youtube videos. This much I learned: 3 types of EGRs.
1.Ported
2. positive back-pressure
3. negative back-pressure
They said determine what type you have and then they show you how to test with vacuum pump. They also said to make sure you don't have a vacuum leak some place else before focusing on EGR.
Another back yard mechanic told me a number of national auto parts retailers will plug into your trucks computer and tell you what trouble codes are coming up. This could be used to narrow down causes.
Finally I got prices for new EGR of 75-85 dollars.
#4
1) Go to fordfuelinjection.com for info and a how to on pulling codes with a paper clip.
2) Egr is used to control Nox emissions not hydrocarbons. Pulling the line off an EGR valve at idle would have no effect since there should be no vac signal at idle.
3) High HC is usually caused by faulty ignition, vac leaks, or an issue with the injectors or fuel pressure reg.
4) Save your money and sanity and don't replace any parts without testing them. Test the new ones too.
5) Good Luck
regards
rikard
2) Egr is used to control Nox emissions not hydrocarbons. Pulling the line off an EGR valve at idle would have no effect since there should be no vac signal at idle.
3) High HC is usually caused by faulty ignition, vac leaks, or an issue with the injectors or fuel pressure reg.
4) Save your money and sanity and don't replace any parts without testing them. Test the new ones too.
5) Good Luck
regards
rikard
#5
Try doing a general tune up on the truck. New cap/rotor/plugs/wires, throw some fuel injector cleaner in the tank and check for vacuum leaks. Make sure your air filter is clean as well.
A partially stuck open EGR valve could cause excessive hydrocarbon emissions. It might be a good idea to pull it off, and verify that it is closing.
Also keep in mind that with a truck as old as yours, the catalytic converter(s) may be starting to get tired.
A partially stuck open EGR valve could cause excessive hydrocarbon emissions. It might be a good idea to pull it off, and verify that it is closing.
Also keep in mind that with a truck as old as yours, the catalytic converter(s) may be starting to get tired.
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SpicyChxTacos
Explorer, Sport Trac, Mountaineer & Aviator
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11-23-2004 03:34 PM