I looked it over in the ETM on a 96, the only other thing in that circuit is a splice (S139) and that goes to the injectors...... The ECU connector is pin 19 on the bottom connector, pin 3 and 8 on the MFU connector.

 

Well every thing has been cleaned and I changed out my fuel pump with my spare. I did gain 2 psi with that and now sitting at 37. But still having the problem. I broke out my test light and i have a steady 12V on the battery leg to the valve and on the ground side (control side from ECU) I have no ground until a min or 2 and then i have a pulsing light.

One thing i did do was try and send a purge valve open command from my Britpart programmer and did not get anything. I did sent it a fuel pump command and it worked.
I find it strange that it fires with the engine running but not when I tell it to.

 

If you have a copy of the Rave I suggest reading the Emission Control section - Evaporative Control System Pre Advanced Evaps to get an idea of how it should work. There is a test to check for leaks between the purge valve and the fuel tank which I thought might be interesting. The purge valve shouldn't be opening while the truck is idling but while it's moving...... Valve is supposed to be open while off, closed during idle and open while moving. Do you have any other pending codes besides the 1179?

 

I'm hitting the book as I'm typing this and will test it out. As for the codes I do not have any other at this time.

 

The pulsing light...... and it's coming from the ECU...... that circuit within the ECU is either faulty or getting bleed over from another circuit within the box. I'd think faulty if it wouldn't accept a test command. I'd hate to ask but do you have another ECU to test with? It's either that or opening the ECU and seeing if anything is not like it should be or just unplug the purge valve. You'd want to change over the fuel cap to a vented one if you unplug it otherwise the tank may collapse. This is me just thinking but I wonder if robertf's adaptives file clearing would do anything?

 

Update: So i ripped into the tank and all the crap back there and did find a leak. The Line going from the canister to the vapor separator has a fitting and it was leaking. I cut it out and replaced it with fuel ling and clamps.

Second i found that my vent hose from fill neck to tank had several major cracks in it. Also the fill hose was just about shot with cracks too. Both changed.

As for the the purge valve it is still pulsing but when it does air is not being pulled from the vent on the canister any more.

On my programmer I can reset adaptations, will that do the same thing as robertf's file?

 

Yes, exactly the same thing on reseting adaptions, give it a try. Glad you poked around the fuel tank, my filler hose and vent lines where same shape. Knowing that I figured yours might be about the same so I wanted you to read what was in the Rave. Try the adaption clearing and see if that does anything with the canister purge now that it's not sucking air.

 

I did a reset and a little bit of a change in the idle, I'm going to try my old ECU. The only thing that may prevent me from using it is if its not paired with my alarm box, and keep the truck from starting.

 

Living on the wild side eh? Can the Britpart pair the alarm to another ECM?

 

Hmmm.... I have never tried that but I will give it a go if I have a no start issue.