The power does indeed go through the switch

 

Yes






Another very likely scenario based on other posts.

 

Thanks for the attachment. Looks like I need to jump the R/V wire to the BR/W wire to get the rear pump running past that switch. I really hope its just old/tired contacts in that switch.

 

That is a Red wire with a yellow stripe (R/Y) and not R/V.

 

Thanks, I was reading that wrong. Looking at the switch, I need to jump terminal 5 to 4 to run the pump and terminal 2 to 1 to get the sending unit to come to life on the harness. I already made my jumper wires to check when I get home.

 

Now that the week of me working on everyone else's stuff is over, I can get back to the truck. I borrowed the fuel psi tester from Autozone again, but someone had lost/kept the Ford adapter's pin to depress the schrader core pin. So I could never get the gauge to read on the rear pump.

I ordered a gauge and adapter and have it at my house now. This afternoon or tomorrow will be the time to get this resolved or figured out. I have off until the 19th after today, and some time between now and then, the truck is getting its new hitch installed and will be used for its intended purpose: to tow the boat without having to rely on my brothers truck.

I could tow it with the Ranger, but it would be really sketchy if I had to come to an abrupt stop.

 

Checked my switch, it had same power out to both pumps when selecting back and forth. Front pump: 52 psi, rear pump: 40 psi. Next step is to check the power at the plug to the pump itself. I might see if I still have the old, original rear pump that worked before all of this to swap back in, or at least cut off its QD's and solder them shut to make plugs to take the front pump's supply check valve and return pilot valve out of the loop for certain when testing the rear pump.

Its strange that the new pump had the same 52 psi when first installed and with maybe an hour of run time on it, it starts to mess up........
I would also think that a front pump check valve problem would come and go, but I get the same low psi reading on the rear pump no matter how many times I swap back and forth.

I hadn't gotten any other testing done yet because I got wrapped up in playing appliance repair man for my sister and parents, and also renovating my laundry room.

I have to go though the dash and pillar trim of that truck and fiberglass some mounting clips and screw down points back together. They have cracked over the years of New Orleans roads jarring the truck horribly.

Then some felt in the spots that rub and the majority of my squeaks and rattles will be gone.

 

When doing the test are you grounding pin #6 of the self-test plug and turning on the key?
If you are just turning the key on and off that does not work very well and tell us (you) very much unless you are checking leak down.

 

I am checking the psi with the truck running, idling, revving, in park, in gear with the brakes on, etc.

 

Okay, new round of codes. The light has been coming on more when I drive. I hooked up the reader tonight and got these codes with Key On Engine Off:

332: Insufficient EGR Flow Detected
334: EGR Closed Valve Voltage High
543: Fuel Pump Secondary Circuit Fault

I think the 543 may have been stored in there from me working on fuel pumps in the past, swapping back and forth a bunch and hasn't been erased. How long are codes held for on OBD 1 if the fault doesn't come back? I still haven't gotten the rear pump sorted out. Been running on just the front and the truck still runs great on that tank.

The light comes on at various times when driving, but it seems to be mainly if I go from somewhat hard acceleration to coasting. If I drive steady for a while, it goes back out.

Any ideas where to start looking for this one?

 

See RLA's post #19. Luckily EGR isn't a very complex system. You need vacuum to the EVR, and the EVR is controlled by the PCM. If PCM commands EGR flow the EVR passes the vacuum on to the EGR valve. I believe a 95' truck used an EGR valve position sensor to check if EGR opened when the PCM commanded it to. So, if you get a code for valve not opening, you need to check that the EVR is being supplied vacuum. Another easy check is if the truck stumbles at idle (might even stall) when you apply vacuum straight to the EGR valve. If you have good vacuum to EVR and the engine idles poorly with vacuum applied to the EGR valve itself, you dig more. Getting a little deeper, T in a vacuum gauge between EVR and EGR valve, tape gauge to the windshield, and go drive it. How much vacuum is supplied to EGR?

The other thing to check, is the EGR valve position sensor. I've not had to go there, so hopefully someone else chimes in. Otherwise I've seen a few very good tutorials via Google searching for "Ford EGR diagnostics" or something like that.

When I had an EGR issue, the code said insufficient flow (96' F150 with DPFE to detect EGR function, little different than 95' & older), but in actuality there was excessive vacuum applied and the EVR was supplying vacuum at all times (it shouldn't open EGR valve at idle or WOT). New EVR and I was set. My father always said you can trust a code to point you to a system but don't blindly believe the exact word of the code (in some cases).

Happy diagnostics!

 

First off a 332 code is not an Key On Engine Off code. It is either a CM or KOER code.
I will guess it is a CM code:
Continuous Memory DTC 332 indicates the EGR valve did not open with the engine stabilized and the EVR solenoid duty cycle present sometime during vehicle operation.
Possible causes:
-- Obstructed or cracked hose to EGR valve.
-- Icing.
-- Damaged EGR valve.
-- Damaged EVR solenoid harness.

I will also guess then rhat the 334 code is also a CM code but it could be a KOEO, CM or KOER code.
Continuous Memory DTC 334 indicates the EGR valve was open while the engine was stabilized and at idle sometime during vehicle operation.
Possible causes:
-- EGR valve not seating.
-- EVR solenoid allowing excessive vacuum to EGR valve.
-- Damaged EVP sensor.

An the CM 543 code but this one could also have been a KOEO or as listed below a CM code.
A Continuous Memory DTC 543, without the presence of a Continuous Memory DTC 556, indicates that during vehicle operation one of the following has occurred:
-- Open in the B(+) circuit between B(+) and the fuel pump relay.
-- Fuel pump relay contacts opened.
-- Open in the power-to-pump circuit from the fuel pump relay to the FPM splice, if applicable (refer to «schematic»).
-- Left/Front HO2S circuit short to power (with dual HO2S).

 

Thanks for the help!

Yeah, those codes were with the engine off, but they were after the pause, so they were CM codes. I really need to read the manual for the code reader more.

I'll clear the codes to get rid of the 543 and make sure it was just from me trouble shooting pumps previously. Then I can sort out the EGR codes.

 

What is this part with the vacuum and electrical connector below and to the right of the EGR valve?



I had been getting the 332 code more and more while driving. The check engine light steadily comes on and off while cruising with the cruise control on while on the interstate.

After pulling that one code tonight, I started looking around and that vacuum connector had the top port of the hoses going to the bottom port of the item and the bottom port of the hoses was open to atmosphere as was the top port of the item.

Before and after hooking that up correctly, I took the vacuum line off of the EGR valve and hooked a gauge to it. At idle, zero vacuum, as I rev the engine up steadily to hold higher rpms, the vacuum climbs up to 7 inches and as soon as I let go of the throttle, it drops right back to zero. So the EVR seems to be doing its job. Hooking that item up correctly doesn't seem to affect to vacuum signal to the EGR.

I was wondering what this other item is that had the hoses on incorrectly how it might affect EGR operation or feedback info to the PCM.

 

Closer view. The EVR is behind the EGR's electrical connector. The part that had the hoses hooked up wrong have a hose that Tee's off of the lower hose and goes forward to the EVR. I think..... I'll look at it again tomorrow when the sun is out.