Disabling EGR and fuel pressure solenoids
 

I plan to disable my EGR and fuel pressure solenoids this week and I'd like a little guidance if possible. Looking at the worksheet attached here: https://www.evolutionm.net/forums/5634236-post1.html am I correct in thinking I need to change the FCA bit.9 and FEA bit.7 to 0? How about FAA bit.11? Now, with these bits disabled will I be able to completely remove the solenoids or will they need to remain plugged into the wiring harness and just tucked out of the way?

Thanks!

yes you can just change all the evap and egr stuff to zero or the easiest way is to change the periphery 2 hex to 0001 (you have to enter it as 0x0001) and yes when you do that you can take the solenoids completely...

Are you sure you can really yank the solenoids with the above values, or do you need to do the 0x0001 value you entered? I have FCA to 0 and have both of those sensors unhooked, but still plugged in.

when you enter 0001 in the p2 hex it changes all the 1's to 0's except for bit 0 in fca. i did this and completly removed all the solenoids (fpr, egr, and evap's) and everything associated with them and havent thrown a code. obd2 test shows evap and egr as N/A so it will pass inspection.

Any nothing else important is disabled by doing so?

FCA is all well defined except for the last bit (the 1 of the 0001) but turning them all off is just some of the emission BS as pointed out...cures the P0300 as well.

Warning: You may not pass an emissions test by using this method.

I turned off the EGR by changing FCA bit 9 to 0. This will pass MA emissions which are fairly strict.

I see EVAP is listed as FCA bits 13 and 14. I have no tested those yet but will hopefully in the near future.

What result does bit 11 have in the FAA besides disable EGR? Does enabling ignition advance have an effect on timing somehow? What is the full result or purpose of enabling ignition advance is what I'm asking.

Where can i find the hex data so that I can get the P2 table into the ROM so that I can disable all this stuff? I can't seem to find the definitions anywhere.

This might help evo8dad.




<!-- *** ECU PERIPHERY *** -->

<table name="ECU Periphery00 Hex" category="Periphery" address="f9a" type="1D" level="2" scaling="Hex16"/>
<table name="ECU Periphery0 Hex" category="Periphery" address="faa" type="1D" level="2" scaling="Hex16"/>
<table name="ECU Periphery1 Hex" category="Periphery" address="fba" type="1D" level="2" scaling="Hex16"/>
<table name="ECU Periphery2 Hex" category="Periphery" address="fca" type="1D" level="2" scaling="Hex16"/>
<table name="ECU Periphery3 Hex" category="Periphery" address="fda" type="1D" level="2" scaling="Hex16"/>
<table name="ECU Periphery4 Hex" category="Periphery" address="fea" type="1D" level="2" scaling="Hex16"/>

<scaling name="blobbits" storagetype="bloblist" storagebits="1">
<data name="0" value="00"/>
<data name="1" value="01"/>
</scaling>

<table name="ECU Periphery00 (F9A) Bits" category="Periphery" address="f9a" type="2D" level="2" scaling="blobbits">
<table name="Periphery Bit Number" type="Static Y Axis" flipy="true" elements="16">
<data>bit.15</data>
<data>bit.14</data>
<data>bit.13</data>
<data>bit.12</data>
<data>bit.11</data>
<data>bit.10</data>
<data>bit.09</data>
<data>bit.08</data>
<data>bit.07</data>
<data>bit.06</data>
<data>bit.05</data>
<data>bit.04</data>
<data>bit.03</data>
<data>bit.02</data>
<data>bit.01</data>
<data>bit.00</data>
</table>
</table>

<table name="ECU Periphery0 (FAA) Bits" category="Periphery" address="faa" type="2D" level="2" scaling="blobbits">
<table name="Periphery Bit Number" type="Static Y Axis" flipy="true" elements="16">
<data>bit.15 .</data>
<data>bit.14 .</data>
<data>bit.13 .</data>
<data>bit.12 .</data>
<data>bit.11, 0=Disable EGR Test .</data>
<data>bit.10, 0=Disable "weird unknown" timing pull at cruise .</data>
<data>bit.09, 0=Disable cat-Warmup Ign Retard Tables .</data>
<data>bit.08 .</data>
<data>bit.07, 1=Enable High Oct Ign Map Lookup and many other subroutines .</data>
<data>bit.06, 1=Enable WG solenoid? Enable Speed Limit Test .</data>
<data>bit.05 .</data>
<data>bit.04 .</data>
<data>bit.03, 0=Disable Immobilizer function .</data>
<data>bit.02 .</data>
<data>bit.01, 0=Disable Rear O2 Test and fault report .</data>
<data>bit.00 .</data>
</table>
</table>

<table name="ECU Periphery1 (FBA) Bits" category="Periphery" address="fba" type="2D" level="2" scaling="blobbits">
<table name="Periphery Bit Number" type="Static Y Axis" flipy="true" elements="16">
<data>bit.15 .</data>
<data>bit.14 .</data>
<data>bit.13 .</data>
<data>bit.12 .</data>
<data>bit.11 .</data>
<data>bit.10 .</data>
<data>bit.09 .</data>
<data>bit.08 .</data>
<data>bit.07 .</data>
<data>bit.06 .</data>
<data>bit.05 .</data>
<data>bit.04 .</data>
<data>bit.03 .</data>
<data>bit.02 .</data>
<data>bit.01 .</data>
<data>bit.00, 0=Disable Lean Spool .</data>
</table>
</table>

<table name="ECU Periphery2 (FCA) Bits" category="Periphery" address="fca" type="2D" level="2" scaling="blobbits">
<table name="Periphery Bit Number" type="Static Y Axis" flipy="true" elements="16">
<data>bit.15, P0443 P0446 P0403 P0243 P0090 P2263 .</data>
<data>bit.14, P0450 P0451 P0452 P0453 Evap Pres. Sensor .</data>
<data>bit.13, P0441 Evap Incorrect Purge Flow .</data>
<data>bit.12 .</data>
<data>bit.11, P0031 P0032 P0037 P0038 .</data>
<data>bit.10, P1400 MAP Sensor .</data>
<data>bit.09, P0401 EGR Test .</data>
<data>bit.08, P0506 P0507 Idle Test .</data>
<data>bit.07, P0170 P0171 P0172 .</data>
<data>bit.06, P0134 Front O2 Sensor No Activity .</data>
<data>bit.05, P0000 - or with bit.4 .</data>
<data>bit.04, P0000 - or with bit.5 .</data>
<data>bit.03, P0132 P0136 O2 Sensor Circuit .</data>
<data>bit.02, P0133 P0159 .</data>
<data>bit.01, P0421 not in FSM .</data>
<data>bit.00 .</data>
</table>
</table>

<table name="ECU Periphery3 (FDA) Bits" category="Periphery" address="fda" type="2D" level="2" scaling="blobbits">
<table name="Periphery Bit Number" type="Static Y Axis" flipy="true" elements="16">
<data>bit.15, P0128 Coolant Temp Below Reg. Temp .</data>
<data>bit.14, P1603 Battery Backup .</data>
<data>bit.13 .</data>
<data>bit.12 .</data>
<data>bit.11, P0180 P0183 P0461 P2066 Fuel Sensors .</data>
<data>bit.10 .</data>
<data>bit.09 .</data>
<data>bit.08 .</data>
<data>bit.07, P0551 Power Steer Pressure Sensor .</data>
<data>bit.06, P0500 Vehicle Speed Sensor .</data>
<data>bit.05 .</data>
<data>bit.04 .</data>
<data>bit.03 .</data>
<data>bit.02, P0234 P0243 P2263 Turbo Overboost .</data>
<data>bit.01, P0510 Closed Throttle Switch not in FSM .</data>
<data>bit.00, P1715 P1750 etc .</data>
</table>
</table>

<table name="ECU Periphery4 (FEA) Bits" category="Periphery" address="fea" type="2D" level="2" scaling="blobbits">
<table name="Periphery Bit Number" type="Static Y Axis" flipy="true" elements="16">
<data>bit.15, P0140 1=Enable Rear O2 No Activity test .</data>
<data>bit.14, P0069 MAP vs Baro .</data>
<data>bit.13, P0111 Intake Air Temp Circuit .</data>
<data>bit.12, P0554 Power Steering Pressure Sensor Circuit .</data>
<data>bit.11, P1530 A/C1 Switch .</data>
<data>bit.10 .</data>
<data>bit.09 .</data>
<data>bit.08, P0830 Clutch Pedal Switch A Circuit .</data>
<data>bit.07, P0090 Fuel Pressure Circuit .</data>
<data>bit.06 .</data>
<data>bit.05 .</data>
<data>bit.04 .</data>
<data>bit.03 .</data>
<data>bit.02 .</data>
<data>bit.01 .</data>
<data>bit.00 .</data>
</table>
</table>

Awesome thanks. All I needed was the first section of hex info, I have the rest but, I haven't filled all the bits in so thats helpful. Where did you find this? I tried searching for about an hour and came up empty handed.

One last question, changing the hex to 0001 - will that disable the FPR solenoid? The car I'm working on still needs that.

excuse the noob question

but why would you want to disable the FPR solenoid? do you need an aftermarket fpr in order to disable the fpr solenoid?

The sole purpose of the EGR system is to reduce the formation of Oxides of Nitrogen (NOx). These are formed when the temperature in the combustion chamber reaches very high levels. To avoid this situation, the EGR system is used to lower combustion chamber temperatures by admitting small amounts of exhaust gas back into the combustion chamber. As you can imagine, exhaust gas does not burn, and does not help the combustion process. If the EGR system would admit exhaust gas into the combustion chamber at idle, it would cause a rough idle, or stalling. As a result, EGR does not allow exhaust gas into the chamber at idle (nor at wide open throttle, more on that later...). To accomplish this, there has to be some way of controlling EGR flow.

The way this is accomplished is actually quite simple. First of all, there is a round, flying saucer - looking part that mounts on the intake manifold. This is called the EGR valve. There is an opening in the intake manifold from the cylinder head that allows exhaust gas to move up to the valve. When vacuum is applied to the valve, it allows the exhaust gases to pass. To control when the valve receives vacuum, an EGR solenoid is used. This part mounts on the passenger side near the back of the intake manifold. It has a vacuum line which supples ported manifold vacuum, and another vacuum line running to the EGR valve. When the ECM requests EGR to be ON, it sends a signal the the EGR solenoid, which then allows vacuum to be applied to the EGR valve. When the ECM wishes EGR to be off, the solenoid will cease to apply vacuum to the EGR valve.

The ECM will turn on the EGR solenoid by grounding it. It does this via pulse width modulation (PWM). This means that the ECM will turn on and off the solenoid many times a second. Just how many times this occurs will affect the amount of vacuum applied to the EGR valve, and therefore the amount of exhaust gas admitted into the combustion chamber. During the time that EGR is requested by the ECM, fuel output and spark advance are also altered. More timing is added, and the fuel mixture is leaned a bit.

During WOT (wide open throttle), the ECM shuts down EGR. Since EGR will play no role whatsoever under WOT, it will not impede the engine's ability to generate horsepower.

How does the ECM know if there is a problem with the EGR system? Well, the answer depends on what year TPI setup you have. If you have an 85-89 setup, then there will be a single wire that goes to the base of the EGR valve. This is basically a temperature switch. When the ECM requests EGR, it will check this wire to see if there is a change in temperature. If no change is detected, the ECM will think there is a problem with the system, and will throw a code 32. Most of the time, the problem is the temperature switch that is bad. However, you should first check for vacuum leaks, check that all vacuum lines are properly routed, check the harness connector at the EGR solenoid with a voltmeter, and make sure that the EGR passages are not clogged with deposits.

The 90-92 TPI setups did not use a temperature switch on the EGR base. Instead, the ECM monitors the MAP voltage to determine if an EGR request was successful or not. When EGR is turned on, engine vacuum will lower a little. The ECM will throw a code 32 if it suspects that the EGR request was not successful.

So what would someone gain by disabling EGR? Just about the only thing would be less parts under the hood. Basically, removing EGR gives you more space (although not much). To correctly disable EGR from your vehicle, you MUST at the very least, disable it in the prom. This is done by setting the minimum temperature to enable EGR to 151 degrees Celsius (maximum allowable temperature), and setting the minimum vehicle speed to enable EGR to 255 mph (maximum allowable speed). Since the engine will never reach either of these conditions, EGR will never be requested by the ECM. Since EGR will never be requested, it does not matter if you leave the EGR system all installed in its original place, or if you remove it from the car. If you decide to remove it, you will need an EGR block off plate to cover the hole in the intake manifold.

If you simply remove the EGR system from the car, but do not disable it in the ECM, you will run into significant problems. You will likely run into detonation, the engine will run very poorly, lack power, and will probably run on the hot side as well. In addition, you will get a code 32 before running very long. If you recall from before, the ECM alters fuel and spark advance when it thinks EGR should be on. If no EGR flow is possible because you removed it, you will have a lean condition which will be further aggravated by advanced timing.

^^^ i think you need more detail :) lol