I have an '88 F-250 with the 5.8l V-8. It is strictly an off-road farm truck and I just want to keep it running reliably. I have a problem with the plugs fouling - I remove them and clean up or replace, but in a few days (or sometimes hours) they foul so bad the truck will not run. I have replaced plugs, wires, cap, rotor, coil, and pcv in an effort to clean this thing up, but no luck.

I am suspicious of the smog pump system, catalytic converter, and oxygen sensor. The truck has been sitting a while since I last messed with it, and when I started it today the smog pump was seized up.

I have had other early '80's ford engines which I have removed the pump and cat and been OK, can I scrap the pump, converter, and all associated smog plumbing? If I do, do I need to reinstall the O2 sensor in the exhaust pipe, or will the computer run in "open loop" mode if I simply disconnect it?

My guess is that the catalytic converter is plugged and the engine 1) can't breathe and 2) the O2 sensor is giving bad readings and causing the mixture to get rich.

Am I on the right track? I saw another post regarding the pump removal - it looks like I can simply rip it out and run a shorter serpentine belt.

Thanks.

 

You can't run without an O2 sensor. You can take the pump and cat off without any ill effect, but the PCM needs the O2 sensor input to run correctly.

 

Thanks.

Can I just chop off the air tubes at the manifold and beat them over with a hammer? I can't see any way to get them out and plug the holes (pretty rusty)

Can I test the O2 sensor with a voltmeter? Should it range from 0 to 1 volt?

 

i agree -leave the o2 sensor in -lose the cats and smog pump , u can disconect the pipes off the pump up to the rubber part of it and stuff a dowel in there with a hose clamp - have the cat tubes brazed over at a welding shop - your truck will run better now - mine did...

 

I had a 94 F-150 with a 302. I pulled the cats of and replaced them with a catalytic Y-pipe. My only problem was from the air pump hose. I stuffed an old sparkplug in there, and crimped it off. It tripped the check engine light once, and only for a few minutes. The engine ran fine, and all I had to do then, was pull the pulley to the air pump, and bought a shorter belt.

 

Oh yeah. Before I plugged up the hose, the engine sounded like a diesel from all the rattling the air pump was doing. It probably didn't cost me more than $200 Canadian by the time I was done. In the end though, short stop and go driving sucked the fuel like it was going out of style. It sounded cool, but man was she a thirsty pig. On the other hand, when on the highway, mileage actually improved. I figure it went from 25 to 30 feet per gallon.