closed loop problems

skippy said:

ok,so back on my ranger project after being sick and dealing with heat wave.my 2.8 runs fantastic in open loop and chokes and sputters in closed loop.have replaced tfi mod,distributor,plugs,wires,cap,rotor,tps sensor,cat convertor,rebuilt carb,map sensor,canister purge valve,coil,ignition module wire harness,replaced valve stem seals,reground vaves,set the valve lifters,adjusted timing to 10deg tdc,checked for loose grounds in engine compartment,new o2 sensor,actually put in oem t-stat to replace non exsitent t-stat removed before i got it.checked diverter vave and air pump with engine running,checked for vacuum leaks.do i need to reset computer,drive for 10 or fifteen miles and then pull the codes?pull them now?what am missing?has very good power in open loop and seems to do ok on gas.i don,t have to worry about emissions as it falls off the list jan 1st,but dammit, i want to get it right.any suggestions will be appreciated.

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skippy said:

open loop basicly is allowed on start up and the computer is not in play,after the engine is warmed up and the temp sensor has reached proper temp the computer takes over control to regulate emissions,as i understand it.and if you romp the pedal the computer allows engine into open for performance and computer again takes over at cruising speeds.thats as simple as i can put it.im begining to think i somehow screwed my computer up,like when i first brought this beast home i would work on it then disconnect the batery negative at the end of each days toil.then i learned this wasn't good.any way the closed loop/open control stategy is explained in the tech library much better than i can lay it out.

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enginepaul said:

First, codes can be re-set.
Check a manual for repairing each code; the best is the Ford emission manual. I got mine on e-bay for about $25.00 but needed a break-out box to do all tests.
Watch the EGR codes! The revision to the manual says that after performing certain tests, ignore it. Not knowing that cost me a new computer that wasn't needed.
Something to watch for: most tests say something like "Remove connector, inspect contacts" I went through hours one one problem, including buying new parts when I finally took apart the connector and found one of the female terminals was bad.
I don't know how to find these items in the archives, but will look after work - time permitting.
Another side note: I use the factory shop manual, the Ford Vacuum and electrical manual and the emissions manual along with other manuals I have on hand = you can't have too much information and you need patience.

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JoshT said:

What type of test did you do? Is 8/27 the date the test was run?

I'm guessing it was the EEC-IV self test, just want to be sure.

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