WUR issue

[schumicat]

after engine drop (replaced trans) and reinstall car starts but immediately dies. Engine was running fine before drop. Definitely fuel related (spark good). Replaced fuel pump and filter. No improvement.

Bought fuel pressure gauges and system and cold control pressures are the same (control should be significantly lower). Read that this can mean the WUR is clogged. I did test I found here of opening the WUR outlet line and no fuel comes out (line pressurized and flowing into WUR). I disassembled WUR and the inlet screen looks clear and I can blow into the inlet and outlet lines and air comes out the little holes on interior part of WUR. WUR inlet/outlet seem be connected only by a metal plate with a pin and spring pushing it. Not sure how the hell this thing works or how to test it further? Don't want to replace WUR unless I'm sure that's what is wrong.

Thanks

[ossiblue]

Originally Posted by schumicat

after engine drop (replaced trans) and reinstall car starts but immediately dies. Engine was running fine before drop. Definitely fuel related (spark good). Replaced fuel pump and filter. No improvement.

Bought fuel pressure gauges and system and cold control pressures are the same (control should be significantly lower). Read that this can mean the WUR is clogged. I did test I found here of opening the WUR outlet line and no fuel comes out (line pressurized and flowing into WUR). I disassembled WUR and the inlet screen looks clear and I can blow into the inlet and outlet lines and air comes out the little holes on interior part of WUR. WUR inlet/outlet seem be connected only by a metal plate with a pin and spring pushing it. Not sure how the hell this thing works or how to test it further? Don't want to replace WUR unless I'm sure that's what is wrong.

Thanks

Sounds like you're following the correct procedures.

One thing to clarify, when you did your test and found no fuel coming from the wur outlet line, are you certain there was fuel coming into the wur from the fuel distributor? You said the system was pressurized but the fuel blockage could be within the fuel distributor since you have confirmed the wur itself is not blocked.

Let us know if you are getting fuel into the wur.

[pete3799]

If it ran good before the engine drop i would suspect something other than the WUR.
Check your fuel delivery at the filter outlet.

[schumicat]

The pressure gauge between fuel distributor and wur shows lots of pressure so fuel is coming out of distributor. Not sure how possible not coming out of wur.

[ossiblue]

Are you able to blow air through the outlet line of the wur (detached from the wur) which goes back into the tank?

Just to be sure we are all on the same page, did you do the following things (not necessarily in this order)?

-Connected fuel pressure gauge set between the fuel distributor and the wur, with the shut off valve on the wur side of the gauge.
-Shut off the gauge valve to the wur, disconnected the electrical connection to the heating element, and started the fuel pump to get system pressure reading.
-Opened the valve on the gauge set and the pressure did not drop.

-Disconnected the outlet line from the wur (or disconnected the line where it enters the return tank tube?) and connected a tube to the outlet to collect the fuel.
-Shut the valve on the gauge set and started the fuel pump.
-Slowly opened the valve to allow fuel to the wur but didn't notice any fuel coming out of the wur outlet.

Does that summarize what you've tested? One very important detail is bold printed--the line connected to the outlet. If you used original line to route fuel into a jar and nothing came out, it's possible the line is clogged.

As you surmise, the wur is very simple--just inlet and out holes separated by a very narrow chamber that changes volume via two thin discs pushed up by a pin/spring mechanism. Since you are able to blow through the wur ports when all pressure is off the diaphragms, there is free flow through the chamber. If the return line to the tank is also clear and you have already disassembled/reassembled the wur, you may want to try the following: Hook everything back up, including the gauge set, but don't connect the electrical heating element. Start the fuel pump with gauge open. Begin to gently knock the pin for the bimetallic lever down into the wur housing. Do you see any drop in pressure? Continue until you are sure the pin has moved low enough to release all pressure off the diaphragm. Still no pressure drop? If still no pressure drop, I'm stumped.

BTW, did you check to see if your gauge set allows air to pass through when the valve is open? Just had to ask as it could be a problem with the valve on the gauge set, seeing that it's new.

edit: couple of posts while I was typing. Return line is not clogged. Suspect the gauge valve.

[boyt911sc]

Originally Posted by schumicat

The pressure gauge between fuel distributor and wur shows lots of pressure so fuel is coming out of distributor. Not sure how possible not coming out of wur.

schumicat,

What are your fuel pressures? Give us some numbers so we would have some idea what's going on with your CIS. If you want to know if fuel is passing through the WUR, all you have to do is detach the return fuel hose (WUR) and plugged the disconnected return fuel line. Test run the FP for 1 or 2 seconds (max.). Install a temporary fuel hose to collect the fuel coming out from the WUR (if any). The return line to the gas tank could be restricted or blocked causing the fuel pressure to register higher than the system fuel pressure. Keep us posted.

Tony

[schumicat]

when I disconnected that outlet line from the WUR and ran the pump (with the FD connected to the WUR inlet) a bunch of gas flowed out of that disconnected return line. So it can't be clogged. I guess that gas was coming from the fuel tank?

Another thing weird is the system pressure is way high, like 90 psi. I took off the pressure valve on the FD and it only had one shim and I removed it, but the pressure is still about 90 psi.

The thing that makes no sense to me is how 90 psi can be going into the WUR inlet and nothing comes out the outlet (with no line connected to it). How can that little metal diaphragm in the WUR seal it so nothing comes out? The only thing I can think of is that my (brand new but cheap) fuel pressure gauge kit has a valve which is not opening (stuck in closed position) so very little fuel is flowing to WUR even in the open position, even though gauge (teed on a line so it is not affected by the valve) shows 90 psi.

Originally Posted by ossiblue

Are you able to blow air through the outlet line of the wur (detached from the wur) which goes back into the tank?

[schumicat]

Tony, I did that test and nothing is comes out of the WUR outlet. The system pressure is high (see post I did same time you were posting).

Originally Posted by boyt911sc

schumicat,

What are your fuel pressures? Give us some numbers so we would have some idea what's going on with your CIS. If you want to know if fuel is passing through the WUR, all you have to do is detach the return fuel hose (WUR) and plugged the disconnected return fuel line. Test run the FP for 1 or 2 seconds (max.). Install a temporary fuel hose to collect the fuel coming out from the WUR (if any). The return like to the gas tank could be restricted or blocked causing the fuel pressure to register higher than the system fuel pressure. Keep us posted.

Tony

[ossiblue]

Try the obvious next. Disconnect the line from the gauge set to the wur and place it in a jar. Start your pump with the valve shut, slowly open the valve and see if fuel flows freely. (Be very careful with that high pressure flow!) Or, much safer, remove the gauge set and try the same test by blowing air through the line.

[boyt911sc]

Originally Posted by schumicat

when I disconnected that outlet line from the WUR and ran the pump (with the FD connected to the WUR inlet) a bunch of gas flowed out of that disconnected return line. So it can't be clogged. I guess that gas was coming from the fuel tank?

Another thing weird is the system pressure is way high, like 90 psi. I took off the pressure valve on the FD and it only had one shim and I removed it, but the pressure is still about 90 psi.

The thing that makes no sense to me is how 90 psi can be going into the WUR inlet and nothing comes out the outlet (with no line connected to it). How can that little metal diaphragm in the WUR seal it so nothing comes out? The only thing I can think of is that my (brand new but cheap) fuel pressure gauge kit has a valve which is not opening (stuck in closed position) so very little fuel is flowing to WUR even in the open position, even though gauge (teed on a line so it is not affected by the valve) shows 90 psi.

schumicat,

It might not be obvious to you but I have made several tests before replicating your problem (high fuel pressure). For a CIS to produce a fuel pressure much greater than the system fuel pressure is to restrict or block the return fuel line. So the question now is where is the blockage happening? It could be anywhere along the return line or even stuck relief valve could do it too.

The way I did it is to segregate or isolate section by section of the fuel return line from FD and WUR all the way to the gas tank.

You will not be able to even start the engine momentarily for a second or two with this kind of back pressure (control fuel pressure). This problem has been discussed in previous posts (old).

Of course fuel would be coming out from the disconnect return line when you ran the FP. The disconnected fuel return line is upstream (near engine) and the restriction/blockage could be somewhere downstream. I have another scenario where this buildup (fuel pressure) could happen but will reserve it for meantime.

Tony

[boyt911sc]

schumicat,

The WUR has nothing to do with the high fuel pressure you are getting!!!! Assuming that the WUR is completed blocked (no fuel passing through) then the control fuel pressure would be equal to system pressure (like closing the shut-off valve of the CIS pressure gauge kit). Do you still follow me?

When you are measuring the control fuel pressure and you shut-off the valve you get the system pressure. This is exactly what a 'no-flow' to WUR condition is!!!!! In short, the WUR is not capable of producing a fuel pressure greater than the system fuel pressure (you could try this all day) it won't happen UNLESS you have flow restriction along the return line side.

I wish I could explain any better than this. Since you have a later SC, you might have inadvertently connected the return line from the FD to the wrong fitting or connection. Lastly, your cheap fuel pressure gauge is not to be blamed for your trouble. Are you sure you have the vacuum booster line connected correctly? Keep us posted.

Tony

[schumicat]

I determined my gauge set is not working right. Some of the quick connect couplers are defective and are greatly restricting flow. That is why WUR was not getting fuel with the test kit. Harbor Freight.... Will get a better gauge set.

[timmy2]

Star TU-14PB Star Products TU-14PB - Fuel Injection Tester – Bosch C.I.S. has worked well for me.
Or the one our host sells.

[boyt911sc]

Originally Posted by schumicat

I determined my gauge set is not working right. Some of the quick connect couplers are defective and are greatly restricting flow. That is why WUR was not getting fuel with the test kit. Harbor Freight.... Will get a better gauge set.

schumicat,

Are using quick disconnect fittings for hazardous chemicals like gasoline? This is a no no practice for handling flammable fluid/s. Assuming that the fitting/connection of your pressure tester is defective as you found it, why would it register 90 psi? Unless the gauge is defective too.

Find a reliable pressure tester and start from the beginning. Even if the connectors are bad and not flowing through the WUR, you won't be able to generate 90 psi. pressure unless you have flow restriction. Your system pressure is set @ 70 psi. (+/-). Keep us posted.

Tony

[schumicat]

virtually all fuel injection testers use quick disconnects, unless I'm mistaken. at least kits that are for multiple makes/models.

not all the couplers were restricting flow. the gauge one wasn't. given the quality of the couplers I wouldn't bet on the gauge being terribly accurate.

Originally Posted by boyt911sc

schumicat,

Are using quick disconnect fittings for hazardous chemicals like gasoline? This is a no no practice for handling flammable fluid/s. Assuming that the fitting/connection of your pressure tester is defective as you found it, why would it register 90 psi? Unless the gauge is defective too.

Find a reliable pressure tester and start from the beginning. Even if the connectors are bad and not flowing through the WUR, you won't be able to generate 90 psi. pressure unless you have flow restriction. Your system pressure is set @ 70 psi. (+/-). Keep us posted.

Tony

[timmy2]

The one I linked you to and the one our host sells do not use quick connectors.

[howard freeman]

I assume the car is the 82 SC & it was running fine before the engine drop?? If this car is a U.S. version,did you remember the reconnect the 12 pin connector in front of the engine. It is located on the bulkhead between the upper shock mounts & is to the left of center. If this isn't connected, the frequency valve wont work & the car won't run correctly & will be hard to start. Quick easy check for the freq valve opps is, turn ign switch on,with air filter removed push up very slightly on the air flow meter arm. You should then hear the freq valve start buzzing. Bad relay under pass seat will also cause it not to function. Hope this helps.
Howard

[boyt911sc]

Originally Posted by howard freeman

I assume the car is the 82 SC & it was running fine before the engine drop?? If this car is a U.S. version,did you remember the reconnect the 12 pin connector in front of the engine. It is located on the bulkhead between the upper shock mounts & is to the left of center. If this isn't connected, the frequency valve wont work & the car won't run correctly & will be hard to start. Quick easy check for the freq valve opps is, turn ign switch on,with air filter removed push up very slightly on the air flow meter arm. You should then hear the freq valve start buzzing. Bad relay under pass seat will also cause it not to function. Hope this helps.
Howard

Howard,

If the 14-pin connector is not hooked up or connected to the engine harness, schumicat won't be able to crank the starter at all or run the FP for the test. So 14-pin connector is out of the equation.

Tony

[howard freeman]

Originally Posted by boyt911sc

Howard,

If the 14-pin connector is not hooked up or connected to the engine harness, schumicat won't be able to crank the starter at all or run the FP for the test. So 14-pin connector is out of the equation.

Tony

You didn't read the post correctly! I said 12 pin connector,"not" the 14 pin at the regulator panel.
Howard

[schumicat]

it is connected. I will check that it is operational.

Originally Posted by howard freeman

You didn't read the post correctly! I said 12 pin connector,"not" the 14 pin at the regulator panel.
Howard