I have been chasing a p1179 pending code for some time now. I have done lots of reading on here and have checked everything and replaced a few parts to try and solve it. What i have found is my purge valve is pulsing open and closed all the time (can feel and hear it) I'm thinking this is not normal.

Second thing i have noticed the canister is sucking in air on the port that has no hose attached to it. If i thinking right that's an "out port" and should not be sucking air in. I put a cap on it the engin runs great, and pending code goes away.

What would my next step be to resolve this. New purge valve, Canister, or....?

 

Long term fuel trim too rich, banks 1&2 (AMFR (Air Mass Flow Rate)) P1179 Your sucking in too much air......uh duh.

Normally with engine running it should be shut and only powers open when ECU performs a purge of the charcoal canister fuel vapors.

I would try replacing the purge valve, it's held shut by a spring, could be a problem with the spring and opening through vacuum pulses from the motor. With no other codes and by blocking off the charcoal can breather it fixed it right, right.

 

I have a new one on the way.

I was thinking a new valve just wanted a second opinion. Not a fan of tossing parts in just cause.

Thank you

 

Your welcome. I'm with ya brother, not a fan myself. I usually take things apart to find out why and then proceed. Post up the conclusion.

 

This is rumored to work for a '97 AEL truck. I suspect by your description yours is non-AEL though.


Dorman 911-800 Fuel/Emissions Purge Valve

 

I have heard that it will work with a non- ALE too. I hope that's true because that's the one I ordered. If not the only one I could find would be the one from ab for $400

 

Works fine on my non-AEL '96.

 

So i have replaced my valve and I'm still getting the same problem. What I have noticed is that when I start it up it will be closed all the time and after about a min or 2 it will cycle the valve a few times then it will be closed again. After 30 seconds to a min it will start its rapid open and closing. I ran the truck for a good 45 mins and it continued to do this the whole time. I put a piece of paper over the air vent on the canister to see if it fell off and it never did until i turned off the truck.

 

There's a whole bunch of things I'd like to say but can't print them.

Do you know what the MFU is? It's that small black box about the size of a pack of smokes on the same inner fender near the charcoal can. It's a series of two or three relays and only one gets used. The relay uses points like distributors did. Check those points. The cover comes off the relay base by prying it, not too difficult. Check the points for heavy pitting, that can make/break electricity and would also make the fuel pump run on/off too. That relay pack plus the ECU are the only two items in the electrical loop. Have you taken off any of the ECU's connectors before? Do you know where the ECU is? By the windshield washer tank under a squarish black cover. Remove those connectors, check em for any corrosion. LPS the snot out of the pins and sockets, let dry for a few and reconnect.

 

Yes I have removed the ECU before when my Alarm box crapped out with a matching set so i will clean all the pins and connectors. and for the fuel relay I have cleaned the points before but it has been a long time so i will give it a go. thank you