SRVirtual

Quick question probably easy for someone out there to answer... I have been cleaning up my new 86 GT's engine (had a previous oil leak now fixed) . I took the intake manifold off and the gaskets for the throttle body is just shot. Im going to be replacing that but what is the piece that is inbetween the throttle body and the intake manifold. The gasket looked like it was exactly the same but when I tried to take that one off it was dry rotted so bad it has completely fallen apart. I just want to make sure if i get 2 throttle body gaskets that they will both be the correct gaskets to be replacing.

MIKE86

thats the egr adapter..has two coolant lines running to it also. if its been on awile they can be a real bugger to get off.

MIKE86

youll want a throttle body to egr gasket and a egr plate to plenum gasket.

SRVirtual

yeah took me a bit to pry it apart!

91stang

i've been wondering this for a while? would my car run ok if i took it off and just plugged it up? so it would be just the t/b going into the upper intake manifold

vristang

The egr spacer is also where the TB cable is attached to the upper intake.
You will need a different way of mount the cable if you pull the spacer.

Check this out for EGR function.


http://www.freewebs.com/vristang/50e...sequipment.htm


EGR Theory and Notes on Removal

Vristang



Background-

The EGR (Exhaust Gas Recirculation) is an emissions device that reduces NOx by decreasing the combustion temperature. NOx (Nitrogen Oxides) are only formed when enough Oxygen and Nitrogen are present and combustion temps are very high. Small reductions in combustion temps can have large effects on NOx output. EGR reduces combustion temps by displacing Oxygen from the intake charge with an inert gas (Recirculated Exhaust). The decrease in Oxygen lowers the efficiency of the combustion process, and therefore the peak temperatures reached during combustion are lower.



The Effects of EGR-

Due to the decrease in the efficiency of the combustion process, the EEC-IV computer will increase spark advance when the EGR is functioning. The loss in overall efficiency experienced due to EGR can be somewhat offset by this increase in ignition timing.



Since the efficiency of the combustion process is being decreased, less power is being created. This will cause the driver to open the throttle body a little more, in order to maintain an appropriate level of power for the driving situation. An open throttle body is easier for the motor to breathe through - the pumping losses are lower.

Due to the fact that the spark can be advanced and that the throttle can be opened farther (reducing pumping losses), one can actually see a gain in fuel economy due to the use of EGR.



Also worth mentioning is the coolant system that runs to the EGR or EGR spacer. The EGR gasses are rather hot when they hit the intake manifold. The coolant in the EGR spacer helps to lower the temperature of the exhaust gasses before they hit the fuel. If these coolant lines are removed, the extremely high temps of the exhaust gasses, mixed with the intake air/fuel charge can lead to part throttle detonation and/or backfiring. Ford used the coolant to lower the temperature of the exhaust gasses to a reasonable level.



Also, note that the EGR will only function at part throttle conditions. The EGR is turned off at WOT, and therefore has little affect (if any at all) on WOT power.



Summary-

The EGR system does not affect WOT power, and can even improve part throttle fuel economy.



Removal of EGR-

Popular belief has been that removing the EGR system and not disabling the function of the EGR in the computer, would lead to part throttle detonation due to the increased ignition timing. For this reason it has been said that the only safe way to eliminate the EGR was to also get a chip or custom tune that disabled the system in the computer.

It turns out that this is not true.

The EEC-IV can recognize when the EGR is no longer functional, and will use alternate fuel and timing strategies when this is the case. There is very little risk of harming the engine by removing the EGR equipment from your EEC-IV vehicle.



Here is a summary table of the alternate strategies used by the EEC when a bad sensor signal is detected (code condition is triggered).




Myth –

Some folks misunderstand what the EGR is, and will tell you that the EGR pulls the exhaust into the combustion chamber to burn any unburned fuel in the exhaust, thereby reducing Unburned Hydro-Carbons. This myth seems to have originated in the days of carburetion, when the understanding of emissions by the public was still rather poor. Remember, the EGRs primary function is to reduce NOx.



This site has some info on the EGR plug which can be used to prevent the check engine light from coming on after disabling the EGR system. http://fordfuelinjection.com/index.php?p=61

whiteout 5.0

but is the same true for speed density?

vristang

Same as what?
Can you clarify what you are asking?

The egr functions the same on MAF as on SD.

jason