[BREADwagon]

Well, in my quest to decrease intake temps and intake manifold temps, I have decided to remove the EGR system. The phenolic spacer for the stock intake manifold (between lower and upper manifold) has no hole for the EGR gases, so no hot exhaust gas can enter the upper IM, lowering intake temps drastically (the combination of the spacer and removing EGR spacer coolant lines.)

The goal of the EGR system is to reduce NO emissions, increase fuel economy (pulls back on fuel injection and burns unburnt fuel in EGR gas) and to reduce pinging. HOWEVER, If I get a fender cold air intake, insulate the intake tube with some sort of sleeve, remove the coolant lines to EGR (no egr gas or coolant to warm it up) and have the phenolic spacer for the Upper IM...intake air temperatures will be SIGNIFICANTLY lower than with the stock EGR/intake system.

Now, assuming EEC is in closed loop and knows EGR is at 0 flow:
-->Shouldn't low intake temps decrease pinging, and increase
-->overall efficiency? Wouldn't this be AS good if not
-->BETTER than having the EGR system? (in relation to pinging)?

So at this point, the entire EGR system is still in tact, but no gases are going to the valve. At partial throttle, the computer will still think there is gases going to the valve, so it will open the valve, adjust timing and fuel injection accordingly, thinking there is EGR gas. BUT THERE WONT BE ANY EGR GAS, causing the car to ping, run like crap etc.

SO! People use EGR position valve sensor (EVP) simulators that fool the EVP sensor input to the computer to think the valve is always closed, which throws a code (32 or 34 saying EGR valve not operating correctly, not opening correctly. It does make the computer think that the EGR valve is in the closed position, but the computer throws the code since it wont respond to the computer trying to open it.)
This keeps the computer in open loop mode, which makes it run like crap... It does however think the EGR valve is closed and inoperable, so it keeps timing/fuel injection in accordance to 0 EGR gas flow into the combustion chamber. But still this doesn't change the fact its in "safe mode".

Correct me if I'm wrong, but that is not a good solution, since although the computer knows there is 0 EGR flow, it is in open loop because of the error code, so the car will run worse than if everything was stock...

NOW, the solution I thought of for this issue, is having the computer flashed to disregard the EGR system completely, operating in closed loop with EGR always at 0.
IS THERE SUCH A FLASH? Is there a chip or piggyback connector that goes in between ecu and ecu harness that intersects the signals and does the same job as the flash?

I could always buy an extra EEC, so I would have one EEC flashed, and one stock. I would easily be able to swap them out, remove the Intake Manifold spacer, reconnect the EGR coolant lines, and have the EGR system running fine. I am going to leave the EGR valve, EGR spacer (not referring to the Intake Manifold Phenolic spacer), EVP and EVR solenoid and all vacuum lines in tact, but with the flash, they would remain dormant.

Drivability at partial throttle and MPG efficiency should not be too negatively affected since the intake temperatures would be so low, and since the EEC is flashed to use 0 EGR fuel/timing tables and in closed loop mode, all would be well in muscle car land.:gringreen

 

[Joel5.0]

Well, in my quest to decrease intake temps and intake manifold temps, I have decided to remove the EGR system. The phenolic spacer for the stock intake manifold (between lower and upper manifold) has no hole for the EGR gases, so no hot exhaust gas can enter the upper IM, lowering intake temps drastically (the combination of the spacer and removing EGR spacer coolant lines.)

The goal of the EGR system is to reduce NO emissions, increase fuel economy (pulls back on fuel injection and burns unburnt fuel in EGR gas) and to reduce pinging. HOWEVER, If I get a fender cold air intake, insulate the intake tube with some sort of sleeve, remove the coolant lines to EGR (no egr gas or coolant to warm it up) and have the phenolic spacer for the Upper IM...intake air temperatures will be SIGNIFICANTLY lower than with the stock EGR/intake system.

Now, assuming EEC is in closed loop and knows EGR is at 0 flow:
-->Shouldn't low intake temps decrease pinging, and increase
-->overall efficiency? Wouldn't this be AS good if not
-->BETTER than having the EGR system? (in relation to pinging)?

So at this point, the entire EGR system is still in tact, but no gases are going to the valve. At partial throttle, the computer will still think there is gases going to the valve, so it will open the valve, adjust timing and fuel injection accordingly, thinking there is EGR gas. BUT THERE WONT BE ANY EGR GAS, causing the car to ping, run like crap etc.

SO! People use EGR position valve sensor (EVP) simulators that fool the EVP sensor input to the computer to think the valve is always closed, which throws a code (32 or 34 saying EGR valve not operating correctly, not opening correctly. It does make the computer think that the EGR valve is in the closed position, but the computer throws the code since it wont respond to the computer trying to open it.)
This keeps the computer in open loop mode, which makes it run like crap... It does however think the EGR valve is closed and inoperable, so it keeps timing/fuel injection in accordance to 0 EGR gas flow into the combustion chamber. But still this doesn't change the fact its in "safe mode".

Correct me if I'm wrong, but that is not a good solution, since although the computer knows there is 0 EGR flow, it is in open loop because of the error code, so the car will run worse than if everything was stock...

NOW, the solution I thought of for this issue, is having the computer flashed to disregard the EGR system completely, operating in closed loop with EGR always at 0.
IS THERE SUCH A FLASH? Is there a chip or piggyback connector that goes in between ecu and ecu harness that intersects the signals and does the same job as the flash?

I could always buy an extra EEC, so I would have one EEC flashed, and one stock. I would easily be able to swap them out, remove the Intake Manifold spacer, reconnect the EGR coolant lines, and have the EGR system running fine. I am going to leave the EGR valve, EGR spacer (not referring to the Intake Manifold Phenolic spacer), EVP and EVR solenoid and all vacuum lines in tact, but with the flash, they would remain dormant.

Drivability at partial throttle and MPG efficiency should not be too negatively affected since the intake temperatures would be so low, and since the EEC is flashed to use 0 EGR fuel/timing tables and in closed loop mode, all would be well in muscle car land.:gringreen

There's a lot of misinformation in that response you got, check the highlighted item..... not having the EGR system operational (= any EGR failure logged).... will cause an automatic EGR system deletion by the ECM logic. Open loop - Close loop A/F control switching will continue to be functional. The ONLY thing the EGR simulator plug does, is cause an acceptable closed EVP sensor output. As soon as the systems "sees" the valve doesn't open, a code 33 is logged, causing the ECM to delete/bypass the EGR and not cause the CEL indicator to be illuminated at the instrument panel.

IOW.... you don't have to pay extra money for a tune that will do the same thing (eliminate EGR) the ECM does on its own when an EGR failure code is logged...... or as the GUFB EEC-IV logic book from Ford specifies.

 

[BREADwagon]

So, only Code 33 is logged? No 34 (for KEOR test - EGR valve not opening?)

I thought any of those codes during running would put the car in open loop "safe mode"?

So your saying, with the correct EVP sensor simulator, the car will only throw and store code 33 and/or 34? AND the only thing that occurs other than storing the code(s), is use closed tables (when at operating temp) with the 0 EGR flow parameter?

I have an '86 GT, not a newer car that would use the 3 digit trouble code system. How do '86s respond to EVP sensor simulators?

 

[BREADwagon]

AND, since I am leaving the EGR valve there, All i need to do is disconnect the Vacuum line.

The EEC will still see the real EVP as closed, and it will not open because the vacuum line is not connected. Ill just cap off the EVR and EGR valve vacuum connector.

WHY do you need to block off ANY EGR tracks if you just unplug the vacuum line? Wouldn't it disable EGR then?

 

[BREADwagon]

That was a typo, I read Code 33 as code 34 on the page i was viewing. So 2 posts ago, the question still applies, but forget about code 34....

Why no edit button?

 

[Joel5.0]

Any EGR code (33, 31, 32, 34) will cause the same EVP Failure Mode Effects Management (FMEM) to be followed...... delete, bypass EGR, and not affect spark advance and A/F control. IOW..... the system will fall under close loop mode with an EGR failure and adaptive learning will not be affected.

If you don't have exhaust gases flowing, temperature in the intake will not be affected noticeably. Reason why the external EGR systems, can use two rubber hoses to monitor the Differential Pressure Feedback Exhaust (DPFE) sensors in other systems.

'86 with a 3-digit format EEC-IV system?..... unless it was a modification, 3-digit code systems weren't introduced until 1990 (IIRC)...... Mustang GT's started in 1994 with the SN95 CBAZA EEC-IV logic.

 

[BREADwagon]

Yea, I was saying my 86 doesn't have the 3 digit error code, and therefore an older firmware of EEC. I was wondering if that affected how it reacts to EGR fault codes.

Since EGR gas wont be flowing, it doesn't heat up the intake EGR spacer, AND it doesn't need the coolant lines... It will lower intake temps. Why else would it need coolant lines? When operational, without coolant lines it would heat up to 300+ deg F, without EGR gas or coolant it will be at air temp...

What do you mean by:

...Reason why the external EGR systems, can use two rubber hoses to monitor the Differential Pressure Feedback Exhaust (DPFE) sensors in other systems.

 

[wantsum5.0]

alot of info here,lol,,but i ran a 87 w/ported e7's with a ceramic clay in the egr port in the heads,f-cam,all goodies.hooked it all up,egr too, ran it for months,and i never got a code or an engine light. i went with mass air though on the 87.i loved it when people couldnt figure out why they couldnt touch their intake and mine was always cold.

 

[BREADwagon]

It wouldn't throw a code because everything is still operational, it's just no EGR gas flow when the EGR valve opens because of the plug....
But the EEC will think there is EGR gas, and pull on fuel. I mean, that will make a leaner mixture, but the computer will be thinking there are parameters in the combustion chamber that are NOT true, and thats what I want to avoid.

That is GREAT to hear though, It affirms that blocking off EGR gas and coolant to EGR spacer will significantly reduce intake temp...THATS WHAT I LIKE TO HEAR!

I just want the EEC to know there is 0 EGR flow and not throw ANY codes.

 

[wantsum5.0]

but i also didnt have the vacume line on the egr.run like a champ.

 

[Joel5.0]

Getting into the EEC logic and changing the PFEHP scalar = 2 (programming EGR function out).... has the same effect in the system as having any EGR failure code logged. Code 33 will only prevent the CEL from turning on.

IOW.... if your only purpose is to delete the EGR system you could either have a chip burned with that scalar change to program the EGR out ($150+)
-OR-
Cause an EGR failure code in the system (¢¢)

The effect in the EEC logic, regarding A/F and spark advance control, is exactly the same.

 

[BREADwagon]

Ah, well I guess I'll do EXACTLY what Wantsum does...just remove the vacuum line to the EGR valve (and use the phenolic spacer and remove/block off the coolant lines to EGR spacer). Since code 33 will only turn off the EGR system and not make the EEC go into a weird safe mode (which I previously thought it did), I guess that's fine.

I thought the EEC could just be flashed? It needs to be physically altered with a chip swapped/soldered on its board? I didn't know that.... I'm not used to "old" ecus (pre OBD2).
Not to mention getting rid of a useless code that I willingly cause is not worth $150+ :nogrinner!

Thanks Joel and wantsum!:bigthumbsup