Hello,

I read on the ford fuelinjection website that if you remove part of the emmisions, the computer compensates for it. But, If you remove all of the emmisions components and the computer does not see any of the sensors, it does not?

The article in question states that if removing emmisions components, remove them all.

Opinions? Mainly talking about the EEC-IV computer.

Anybody have the Ford fuel injection book By Charles Probst? What does it say about the emmisons, complete vs incomplete vs. removed?

Thanks.

 

Some components connect to the PCM and some do not. You can, for instance, remove the cats or modify the PCV system without disturbing the fuel injection system. If you remove all the sensors, I guarantee you the engine will not run at all.

What are you trying to accomplish?

Jim

 

No, no, no.. just the emissions sensors, (i.e EGR valve postion, EGR vac soleniod, TAD and TAB solenoids, associated plumbing, diverter valves, bypass valves air pump, you know just emissions).

I know that I cannot remove any of the engine sensors, (i.e. ECT, AIT,O2, MAP, Knock sensor(if equiped))

Maybe 'sensors' was the wrong word. Even though the actuators are hooked up (electrically), if they do not work right(physically), the computer compensates for the connected component anyway and assumes that it is working correctly.

I guess my question is: Will the computer compensate for a device that was originally installed, even though the device is not connected electrically? Especailly after resetting the computer?

As far as what I have read, the data tables setup in the computer will be empty (contain all 1's) and will never change without the device connected to take measurements from. Remember computers work by using math equations. Using all 1's as a multiplier keeps the pruduct (answer) the same.
So if the sensor (actuator) is not connected at all, does it make sense that the computer would not compensate for it? But if the sensor is connected (computer knows when things are connected to it) and is not functioning, the computer will try to compensate for values is receives back in the form of a signal return. All three wire sensors have a signal return wire, some two wire sensor and actuators use the ground wire ( that goes back to the EEC not to the chassis) as a signal return. Others use chassis ground and a v-ref and signal return.. (ECT and/or AIT sensors come to mind). Without a V-ref and signal return, the computer cannot calculate a value from the sensor and defualt settings are used. Air/fuel/ ingnition maps are preset, but are modified( during operation) to acommidate the input from sensors.

If all this is true, that means any EEC-IV computer will run properly ( according to preset or default values anyway) as long as no emissions equipment is installed (electrically), right?

The O2 sensor is responsible for leaning or richening the system, so if no extra air is introduced (smog-pump to heads), the O2 sensor will not tell the computer to richen the mixture to compensate and will run normally or even lean. (adaptive technology).

And in theory, if you injected air into the combustion chambers, without the computer knowing it( by way of a sensor or actuator of some kind), the computer should richen the mixture to compensate because the O2 sensor would say you have a lean mixture. Does this make sense?

 

You can run "open loop" with a dead or missing O2 sensor. Air density mapping or mass airflow is the primary input, throttle position secondary. I guess what you want to know is what the minimum you need to run not optimum but ok. This is my educated guess.

MAF or MAP sensor
Throttle Position Sensor
Air Temperature Sensor
Coolant Temperature Sensor
Fuel Pressure Sensor
Triggering and rpm sensor on cam, crank, or distributor

Anything having to do with the EGR and AIR systems will generate a CHECK ENGINE light and store codes, but the engine will run without them. The PCM has logic that can tell if there is no change in a sensor reading over a period of time it must be dead.

Jim

 

The emissions control solonoids have no affect on engine operation. If they are not present electrically, you will have a constant check engine light. Your O2 sensor has nothing to do with air injection. The main times air is injected into the cylinder head is during cold start/warm up cycle, and the computer doesn't take a reading from the O2 sensor then anyway. After the engine is warm, air is diverted to the cat, or sometimes just dumped back to the atmosphere, it all depends on operating conditions. Check out this website, it has about all you can think of about EEC-IV: Ford Fuel Injection .

 

Thats where I got my info in my 2nd post, The question is: Will eliminating all the emissions only stuff and resetting the computer allow the computer to run like it never had them in the first place?

I know that the check engine light will be on, but I will disconnect it too.

 

The emissions solonoids have no effect on how the engine runs (that I know of). They will just throw a code, that is all. Just make sure you leave the O2 sensor connected.

 

Actually, the computer reads what it sends the soleniods and take into account what it is making the soleniod do when calculating air fuel mixtures. this may not be true for the TAD/TAB solenoids, but for the EVR soleniod and the EVP sensor, this is very true. Calculations are based on how far the EGR valve opens (EVP sensor), especially in closed loop mode. The EGR closes at WOT, becuase the computer goes into open loop and does not map the fuel mixture and goes to preset values. (that is also the reason behind performance chips that only help WOT, easier to change the values. They do not have the knowledge to change the air/fuel/ignition maps) EGR postion is not one of those preset values, so it is excluded from the WOT values and is shut off.

My question still remains (modified): If I disconnect the EGR vacuum solenoid,the EVP sensor ,block the EGR valve port and reset the computer, will it (computer) calculate like the EGR components were never there in the first place? I would even disconnect the Check Engine Light, You never know, just having the light connected could tell the computer that this is a emmisions controlled vehicle. This is assumming that all other emmisions related components are removed first. i know that just the bulb going out does not stop emmisions controls from working, but if everything is gone, it could have a different effect on the computer. Even Haynes , I believe, lists the check engine light as a component of the emmision controls. It would make sense that the bulb is checked for continuity at the minimum. I think the ford engineers may of been thinking ahead and included this check so that people can not claim that the vehicle did not have emmisions when bought. (just by looking at the dashlight.)

I think I may be going too far with the latter idea, but you never know.

 

There may be some relavent info in this thread worth looking at: https://www.ford-trucks.com/forums/s...134#post973134

I would not remove the EGR, just put a limit plate between the valve and the upper plenum thereby allowing less EGR flow.

You can get a custom made ECU chip that will turn off the emission control stuff also, I am not sure of the cost to you for just that but e-mail me and I will put into contact with my friend who does them.

 

I'm still trying to figure out the point to this thread. Is it to gain performance? This is not the way to do it. If I was after performance and didn't have to worry about emissions thaI would look for a chip or find a pre-emissions motor.

By the way, the computor does not "see" WOT and shutoff the EGR. The reason it is closed is that there is no vacuum to open it at WOT.

 

The reason I am gettting rid of the emmisions is simplicity. Instead of diagnosing the emissions on my 16 year old truck, I will just get rid of it. My EVR valve is toast anyway and keeps the EGR valve open all the way all the time. It causes idle probelms and poor MPG this way. I already have unplugged the vacuum to it just to let it shut. It was already thowing a code any way. My air pump does not have anything in it since the previous ower gutted it. and I have removed the air bypass valve and related hoses on the passenger side of the engine ('88 351w), plugging hoses (and vacuum lines) that I could not remove along the way.

I did find out that the diverter valve (check valve)is not working either after taking the air baypass off. Exhaust from the heads or cat were exiting the left over hoses. I still need to remove that part and the crossover on the heads. But I have not removed any of the electronic items in fear that it will really mess up how my truck runs. Right now I only have one code in the computer that is for the EVP sensor ( which is being cuased by the bad EVR soleniod). The pipe to the cat converter has holes in it and is very hard to get to, I have to get that fixed or plugged soon as the exhaust fumes are coming in the truck with me.(not good).

All and all the emissions system on my truck is slowly disintigrating. I am not putting $100-$400 dollars into my truck to replace all the components when I have no testing in my area anyway. IMO, a waste of time and money (and makes my truck harder to work on). I am already researching converting to carb from EFI and making everything even simpler. Hit a few snags, but working thru them. EFI is good, don't get me wrong. Cold starting is the best. But when pumps start failing, injectors plug up, sensor start to fail left and right, itr all adds up to major money to fix. A carb, on the otherhand, mayneed to be rebuilt every year or every other year. Whoop-te-do, 30-40 bucks and a few hours a year. that seems better than 150 for the fuel pump assemblies, 180 for a set of new or rebuilt injectors, 100 for a computer sometime in the near future ( its 16 years old. How much longer can it last. Anyone?), Plus 100 dollars for all the sensors at some point. I only get 10 -11 MPG now, which I understand is nomal. It can't get a whole lot worse with the carb. (unless my right foot turns to lead, seen that commercial yet? Infinity, I think)

Now you know why! Any answers?

 

O.K. Now I get it. It sounds like you have already removed almost everything though. The cat should be removed also though because it will soon burn out if it hasn't already.
As long as you maintain the sensors related to fuel stragity(?) you shouldn't have a problem.
From what I hear to go carbed all you need other than the obvious intake and carb is a diff ign system.



If you go that way can I have your injection parts?(intake)

 

I must sell them to cover the cost of converting. Right now, the parts I know I need are as follows.


Summit univeral timing cover,( allows mounting of the reverse rotation water pump and use of a mechanical fuel pump.)

A fuel pump eccentric (if not already on it, conflicting opinions)

Dura-spark II dizzy, wiring, ignition box,

Intake, ( factory 4BBL, cheaper)

Carb ( most likely a holley 4160, but concidering a Edl 1405 or 1406.)

Fuel line and vacuum line.

Factory C6 kickdown linkage from a 87 351 4bbl. (junkyard)

And many brackets, wire harness covers, and misc parts that I have not identified yet. Most of the conversion will be removal, and or bypassing EFI components. It will be awhile, as right now I am strapped for cash and christmas is coming fast ( OH Santa Claus!) Never know, I may get this done before then. Anywho, I don't have things all planned out yet, still researching............. But I need to get these things (emmissions) off of my motor, that will make it easier in the long run and cheaper to fix.


If you want to know more details about why and what , see this post:

https://www.ford-trucks.com/forums/s...hreadid=149713

 

I was watching that thread earlier in the week. Didn't make the connection.
Think I'll go work on my truck now.

 

Well, after thinking I had a exhuast leak, I found out the PCV adapter to the pass. side valve cover had come out. That would account for the lost oil and the vapors entering the cab. That was a PITA to get back in. I thought I was going to have to remove the upper intake to get it in. Luckly, I didn't.

But while I was replacing the PCV, I snagged a vacuum line with the glove I had on and snapped it. 'Great' I thought, just what I needed another vacuum leak. ( the PCV was a vacuum leak when not connected) The vacuum line was the one to the vacuum canister so I wasn't worried about something not working,( the EGR vacuum line is plugged anyway). Long story short, I ended up removing all of the vacuum lines to the EGR, canister, sloenoids and air valves. The soleniods are still there plugged in, but they will be getting removed this weekend. Believe it or not, the truck run smoother and quieter after all this was disconnected. And driving it this morning, seemed to have cured a small off-idle stumble that I had. I don't know, maybe is coincedense.

Stepman, what did you do to your truck last night?