TBI EGR Block Off

[Da67goatman]

Is it possible to block off EGR on TBI 350 with out sending the ECM into stupid mode?  My valve and solenoid are both shot and it seemed to run like crap when it worked. (BTW it ran great with the blown out valve)  The block off plates are cheap enough and if i can eliminate one more thing robbing me of power the better i feel.  Any input will be greatly appreciated.

I've heard of other dummy sensors that make the ECM read that everything is fine, is there one for the EGR?

[VileZambonie]

You don't need to block it off, just unplug it. If you don't want to set an EGR DTC you can replace the PROM with an aftermarket one.

[Da67goatman]

From what i gathered out of my Haynes manuals, I can put a block off plate in place of the egr valve and just plug the line from the solenoid and everything will be honky dory.  The plugged line tricks the ecm into reading that the solenoid has opened the egr valve by holding vacuum.  I will try this tomorrow and post some results. 

P.S. Vile, thanks for the response, I would love a new PROM however I have no money, only time, due to college.

[VileZambonie]

Then just pull the vacuum hose off of the egr valve and plug it. Why put on a block off plate?

[Da67goatman]

Plugged the line, but my solenoid is bad so i still have no power and got the trouble code.  I need to locate a new solenoid or figure out how the electrical circuits function and bypass it all together.

[VileZambonie]

When you unhook the vacuum line to the egr valve it IS disconnected from the system. Unless the valve is hung open it won't make a difference either way.

[Da67goatman]

Thought I had finally given in and gave up trying to bypass this, went to the store and asked for egr valve they said 80 bucks, i said no way.  So now I am back trying to bypass this yet again.  Has anyone successfully bypassed the egr on a tbi without getting the Check engine light?  I am trying to get a hold of my uncle, he knows everything about hotrodding, its scary how much he knows.

[Captkaos]

Answer was here:

If you don't want to set an EGR DTC you can replace the PROM with an aftermarket one.

[Da67goatman]

that's the only way?

[1980c10]

figure out how the electrical circuits function and bypass it all together.

not specific to your situation, but if you study your wiring diagrams and egr readings find out what reading or range it is looking for and trick it to to the point it believes it is working could be your solution. it may involve diconnecting wires or connecting them, adding a resistor etc. maybe you can bypass it all together.

[Da67goatman]

That's what I was thinking, I'm working on finding the resistance of the egr solenoid and I will put a resistor in place of the solenoid. Hopefully that will be all that's required, but I have this bad feeling the o2 sensor has some part in determining if the egr is working.

I got 34ohm reading on the solenoid, and radioshack has 1/2 watt resistor for .99.  Next time I am out and about, I'll pick one up and give it a shot.

[1980c10]

right, you'll can probably do the same for the O2, but this is a guess as I haven't tried.

[VileZambonie]

Do yourself a favor and don't put any resistor's in before you blow the ecm.

The ECM monitors EGR effectiveness by de-energizing the EGR control solenoid thereby shutting off vacuum to the EGR valve diaphragm, With the EGR valve closed, fuel integrator counts will be greater than they were during normal EGR operation. If the change is not within the calibrated window, a Code 32 will be set.

The ECM will check EGR operation when:



Vehicle speed is above 50 mph.
Engine vacuum is between 15 and 55 kPa.
No change in throttle position while test is being run.

[VileZambonie]

What exactly are you trying to do anyway?

[1980c10]

I think if you do want to try and "trick' your computer into thinking the egr is working etc you need to know what makes a "call" for the egr to open, it would't be a solenoid(that's what actually opens) but rather a sensor maybe a temp sensor,o2 reading, etc(total guess) then you would replace that with a resister that puts it out of range to turn on. Like Vile says this sounds risky especially if your just guessing. A better solution would be to program it out of the prom. like I said earlier I have no experience in trying to do this; I am just throwing some ideas your way that would need further research. Most likely the most practical solution is to just buy and install whatever part you need replaced to fix the system.