IIRC the one with the black connector that has a single port on each side is for the EVAP purge that runs to the rear EVAP and fuel tank.
The other one is a vent/purge control. While on it passes vacuum through to the EVAP system and connects to a line that vents the system as well.
While you have the pump out you may as well clean and paint the tank exterior. Double check ALL the EVAP and fuel lines as well. When the tank is out you can change them out a LOT easier than when it is in.
Thanks Steve. I'll keep that in mind.
Jesus H Christ. This is why I miss the mechanical fuel pumps on the side of the engine and carburators.
Diesel.
"LIKE"
Ok Well I pulled an oops. I broke one of the evap valves while pulling the tank. I can tell that it had never been pulled out before. It was still set up exactly how it would come from the factory. "rolling chassis" style. All the hose clamps were turned just as they would be installed with the body off. Then I did one worse. Like a dumbass I figured that I could remove the tank hoses without a backer wrench (lazy) and I twisted the tube on the sending unit. Boo! Now I have to wait til Monday for the new sending unit to come from Denver. Any pros/ cons about using a non OEM sending unit? The origional MFG unit was more than double the price! ouch.
Now to voice my complaint about the original install. When they installed the evap hoses they didn't put in a service loop in the line so that the tank could be dropped out. I couldn't figure out what was holding it up there with the straps off and I couldn't even fit my hand up there to check. Slightly irritating. I will be putting longer pieces of hose in there when I put it back together.
No real problems, Basically just a one way valve and the fuel level sender. Not a lot to be wrong.
The lines REALLY stick fast once installed.
Sorry, should have warned you that there isn't any slack. The later ones are almost as bad but because they use plastic lines they can flex more and you can reach the QD connectors easier.
Ok so to recap. This is what I have done up to date: 2 new O2 sensors (front and rear) ($200) 1 new IAC valve (Idle Air Control) ($35) New EGR valve ($80) plugs, wires, Cap, Rotor, Airfilter ($90) New head gaskets Cleaned ports new intake gaskets new exhaust manifold gaskets (all gaskets kit $80) new injector spider ($250) new nut kit ($45) new fuel filter ($25) new fuel pump (upgrade from 61PSI to 65PSI) ($80) New fuel sending unit ($103)
So this has been a long journey, The truck is running a TON better. Still has a slightly rough Idle (I'm guessing that once I run a tank of fuel it will go away) but has a ton more power and has no hesitation after 3000RPM anymore. However the goddamn SES light came on again this morning. I am so fricking irritated at this point. The only two things I haven't done to the emissions system are replace the EVAP canister and replace the CAT. I am guessing that the previous owner did alot of this same stuff because the engine didn't even have exhaust gaskets on it. In a previous post I noted the electrical readings on the EGR valve plug. Does anyone have a clue if the voltages and ohms seemed right?
Ok, So a recap
2 new O2 sensors (front and rear) $100 1 new IAC valve (Idle Air Control) $35 plugs, wires, Cap, Rotor, Air Filter $90 New EGR and gasket $80 New Head gaskets* Cleaned Ports while inside exhaust gaskets* intake gaskets* All gasket kit $70 fuel injector spider $250 fuel pump Upgraded to 65PSI $100 (tested pressures: 55-58 key on, 53-55 running) sending unit $100 fuel filter $25I am extremely tired of this truck at this point. I got it all put back together this morning and while driving to work the SES light came on again. I am at a complete loss now. The only things I havent done to the emissions system is replace the evap system or the CAT. Im going nuts here any suggestions would be helpful. I also posted the following:
I also did some electrical tests on the EGR plug with the ignition on. The results are as follows looking at the female end of the plug with the locking tab up. Left to right pin one registered about 50 ohms pin two registered at almost 0 ohms pin three registered at about 200 ohms pin four registered about 5v pin five registered almost 12v
Can anyone confirm that these readings are correct?
This site has some good diagnostic info on the EGR valve.
Frank
What code is coming up?
Toss a scan tool that can read the actual ECM info from the sensors. Then see what it is actually doing.
12 volts would be battery voltage to the heater circuit. 0 should be the ground line. 5 volts is power to the sensor The ohms readings don't mean much. What does is the voltages during operation.With the way the system works you can watch the voltages pre and post cat to tell you if the cat is OK.
According to that site, The EGR is functioning properly. The code P0401 is = "insufficient Flow". I have read that the vacuum sensor is used in conjunct= ion with the EGR when opening to perform the ECM. A low vacuum due to a vac= uum leak somewhere else could be the culprit of all these issues. when the = EGR opens and the PCM reads low vacuum It thinks that the EGR port is Block= ed. I have confirmed that the EGR is functioning Properly and that the Port= is clear so i think I need to go chasing vacuum leaks now. However after r= unning at 4000 RPM for 2 miles uphill and clearing the codes I got the truc= k to pass emissions. The light came back on this morning but at this point = I just dont care. I have the time to chase this issue this summer when the = weather is better and the days are longer. I appreciate you guys for taking= the time and for your input on this issue.
Vacuum leaks are EASY to find. Start engine now run an UNLIT propane torch along the lines. When you get to the leak the engine rpms will go up from the increased fuel.
On a 95 I would suspect more than a couple leaks and one which you won't find easily is the one that controls the front axle interlock. That line runs down the back of the engine to the transfer case. For your testing you could easily pull it free and just block it. You will lose 4X4 until your done but it would narrow down the search. Another one it the vacuum controls to the heater. That is a line that goes through the firewall and connects to the back of the heater control module. The last one is the vacuum canister hidden in the fender behind the ABS unit. (If that is bad and leaking you can get a vacuum ball from a different vehicle to replace it easily. One from a 90's Chevy van works well and they are cheap).
I did that test and as far as I can tell there was no engine rpm increase w= hile testing any of the vacuum lines. This engine sucks. it is running just= ok. It has a bit of a stutter at idle and durring initial throttle up. How= ever if I put my foot down it responds better than it ever has. I guess sin= ce it passes emissions I will just have to live with this issue and I dont = know what else to do with it.
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