Does it ground the circuit, send 5v or 12v?

In my 88 TBI motor, when I connect the ECM lead to the selonoid, the EGR seems to open (runs very poorly!) I want to see if the ECM is sending a constant signal for the selonoid to kick open or not, but don't know exactly what I'm looking for at the pins.

Thanks,
GOY

 

Look at the wires.

Should be a pink/black, and another one.

If so, pink/black is 12V fused ignition; and the ECM works it by grounding the other lead. Which is how it does most things.

 

Thank you sir

 

The ECM uses the MAT sensor to determine when to operate the EGR. Below a certain temperature in the bin, the ECM will not operate the EGR. This is typically how we disable it.

It's a simple change and LOTS of guys now have the eprom burning equipment. Get together on one of the Regional Boards in your area and see if you can find someone that will make this simple change in your eprom.

 

Hum, don't mind me if I'm a little, well confused.

I'm not really trying to disable the EGR at all. My problem is that the vehicle behaves as if the EGR is constantly open unless:

The vac line is removed from the selonoid OR the ECM is disconnected from the selonoid.

The fact that the vehicle behaves fine with the ECM connected suggests to me that the problem isn't the new selonoid, but rather that there is a constant ground to the selonoid. I haven't got to check the lead yet, I'm a little unsure of where I should go with it if the lead is constantly getting a ground, causing my drivability issue's

Besides, it's an 88 TBI - I pretty much need that EGR if I ever want to dream of passing the NOx requirements here in Ohio. ... unless there's a way of tuning around the egr's emission reducing effect, and map fuel/spark well enough to lower NOx emission without it, which is probably where my prom burning adventure would start - as in I know ZERO about it at this time.

 

Disreguard all that crap above...

Took the multimeter to the clip tonight - looks normal, not a closed circuit.

But here is the loophole - as I understand it.... the front of the selonoid is connected to a full vac source at the front of the TB. (TBI remember).

The rear has two "Ports", one for venting the vac, and the other for egr operation. When I take the EGR hose off of the one I thought was supposed to be for it (the furthest away from the clip) and put it on the one I thought was vent.... the vehicle runs like new.

WHAT GIVES!~!

 

I've got a similar problem, anybody got a vacuum diagram of the 3-port EGR solinoid or pics??

 

You might want to employ a vacuum guage to help diagnose your situation.

 

It's official - it's a GM conspiracy

 

 

The P/N switch would be the park neutral switch I take it?

I'll check the function of those sensors next, but I figured I might get an error code, or ses illumination if they were bad.

 

Figuring & assuming are shortcuts, testing removes them from the equation.

 

TPS shows .59v at closed position, 4.31 at WOT, smooth voltage increase through steady blade travel with no dead spots.

Coolant switch operates normally as well.