SC runs only when in START

[boyt911sc]

Ben,

WUR-089 should be OK too. So you have three (3) choices of WUR's: -045; -069; and -089. I would recommend looking for a WUR-069. These are what I seen in some '79-'80 RoW cars.

Tony

[blg5035]

Tony sent me a -069 WUR to test and in short it did not help. I hooked up all the vacuum lines according to the PET.



Test Results
WUR pn: -069
WUR resistance: 36.1 ohms
Ambient temp: 32 degC
System pressure (with valve closed): 5.0 bar
Cold control pressure (valve open): 5.3 bar
Warm control pressure (harness connected): no change from cold

These are the same results as the test in post #14. Below is a pic of my gage setup as a sanity check. I have used the exact same setup for "good" test results.



Moving on or back to LJ's suggestion the return line from the WUR:

You can run a couple of tests to try and narrow down the pressure issue. What you describe typically points to a blocked WURS or return line from the WUR to the tank. Either disconnect the afs sensor wire in the engine compartment, or remove the relay and jump 30 and 87a to allow the pump to work in the "on" position. Start the pump, open the gas filler cap, and listen for the flow of fuel back into the tank. If you can't hear it, you may have a blocked WUR or return line.

Remove the return line from the WUR. Blow low pressure air through the line and see if you can hear bubbling in the tank. If so, the line is clear but the WUR is still suspect. If no bubbling, the line is blocked and needs to be cleared. Once clear, retest the flow through the WUR.

I did a few things here:
1. With the fuel pump running I listened to the tank. I could hear some bubbles, but it was faint. I am not sure how loud it should have been.

2. I disconnected the banjo bolt on the WUR and fuel came out of the WUR when I ran the fuel pump

3. I reconnected the banjo bolt on the WUR and disconnected the banjo bolt on the same line that is in the back of the fuel distributor. In the PET diagram above the line is #61. When I ran the fuel pump, fuel came out, but I do not know how much should come out. It seemed like a healthy flow without any reference.

LJ, I am a little bit confused with the bubbling in the tank test. Doesn't the WUR fuel going through hose #61 combine with the "system pressure" fuel in the Primary Pressure Regulator? In this case, even if you do not have fuel flow through the WUR circuit there would still be bubbling. If the return line to the tank were blocked, the system pressure would not be able to be regulated to 5 bar since the flow is dead headed.



I tried to start the engine as well and it exhibited the same behavior as previously. The engine fired, but sputtered out. The exhaust gas was very rich which is not surprising given the high warm control pressure (Is this thinking correct? Higher control pressure = more fuel injected?).

Any suggestions on what to do next?

[ossiblue]

I did a few things here:
1. With the fuel pump running I listened to the tank. I could hear some bubbles, but it was faint. I am not sure how loud it should have been.

2. I disconnected the banjo bolt on the WUR and fuel came out of the WUR when I ran the fuel pump

3. I reconnected the banjo bolt on the WUR and disconnected the banjo bolt on the same line that is in the back of the fuel distributor. In the PET diagram above the line is #61. When I ran the fuel pump, fuel came out, but I do not know how much should come out. It seemed like a healthy flow without any reference.

LJ, I am a little bit confused with the bubbling in the tank test. Doesn't the WUR fuel going through hose #61 combine with the "system pressure" fuel in the Primary Pressure Regulator? In this case, even if you do not have fuel flow through the WUR circuit there would still be bubbling. If the return line to the tank were blocked, the system pressure would not be able to be regulated to 5 bar since the flow is dead headed.

I tried to start the engine as well and it exhibited the same behavior as previously. The engine fired, but sputtered out. The exhaust gas was very rich which is not surprising given the high warm control pressure.

Any suggestions on what to do next?

You did not perform the second test I suggested--blowing air through the disconnected return line from the WUR.

The sound in the tank you heard could have been solely from the return fuel from the pressure regulator on the FD. That regulator helps establish the system pressure at ~5 bars. Your tests show the following:

Test 1: Return fuel flows into the tank so the line from the T in the return line--the connection where the WUR return line joins the return from the FD--is open. It doesn't tell you if the return line from the WUR to the T is open.

Test 2: Confirms fuel flows through the WUR, as it should.

Test 3: Confirms fuel is returning to the tank from the FD, as it should, and the line is clear from the FD to the tank as confirmed by test 1.

Your understanding of the return line is correct, but your confusion (as I understand it) is misplaced. From my reading of your posts, you have not checked the section of return line from the WUR to the T connection in the main return line. This is where I am a bit confused by your post #3. You say you disconnected the banjo bolt on the back of the FD that is on the same line that is connected to the WUR. (I cannot see the diagram clear enough to identify the line you mention.) That doesn't sound right to me. The line from the WUR typically goes to a connection (a T ) in the return line that comes from the FD.

BTW, your car should have a three port fuel accumulator, I believe. The bottom port has a line that T's into the return line from the WUR. The line you describe in test #3 should, then, have a line connected to it from the accumulator, and then connect to the main return line.

If this is not how your system is connected, please post.

[blg5035]

The below picture was what I thought the fuel line routing was. Based on what you have said, LJ, this is WRONG and the answer to the question in the picture is YES.

I will look for this "T" when I get the chance and try your test again.

[boyt911sc]

Ben,

For you to be able to produce a control fuel pressure similar to that of a system pressure means you have a blockage on the return line for the WUR or FD. Or you have connected the return line to the wrong fitting.

I have tested that WUR-069 for several hours in two (2) days. There is nothing wrong with this WUR. Go back and review your installation. Double check your fuel return line to the tank. Do not blow air. Use the FP and the fuel pressure gauge to measure the restriction or blockage. If you need further assistance in your troubleshooting, let us know.

Tony

[boyt911sc]

Ben,

You have a flow restriction in your return line. In post #14 it says 53 psi. control fuel pressure!!!!!! When the control pressure equalizes the system fuel pressure, that is a sign of flow restriction or blockage at the return line. There is no way you could make the engine start or run with such an existing condition. I missed it and so with the others.

Fix this problem first and keep us posted. One step at a time on the right direction. You will have this engine running soon.

Tony

[ossiblue]

Originally Posted by blg5035

The below picture was what I thought the fuel line routing was. Based on what you have said, LJ, this is WRONG and the answer to the question in the picture is YES.

I will look for this "T" when I get the chance and try your test again.

Follow the line from the WUR retoun port toward the firewall and you should see where it connects to the return line from the FD. In short, the red line you drew does not terminate at the WUR, but continues to the tank with the WUR line teeing in (along with the accumulator line as well.). You need to check the section of line from the WUR to the T, as Tony mentioned as well.

[blg5035]

I did not see LJ's post #27 before writing this

I traced the fuel lines out this evening and I found what I was thinking was the return line was not what you are referring to. This is what I found:
Please let me know if the flow directions I drew in orange are correct


I disconnected what I labeled as "Return line to tank" and ran the fuel pump. A lot of fuel came out (~500 mL in <30 sec). There was a little bit of "junk" in the first second's worth of fuel that came out, but otherwise the fuel came out clear. However based on my picture of the fuel lines and flow directions above, all or most of this fuel could have come from the accumulator.

Looking at the T, I do not see a way to isolate the line from the fuel distributor to the T from the line coming from the bottom of the fuel accumulator. These lines are "crimped" to the T.

[blg5035]

One more pic of the back of the FD

[ossiblue]

Don't worry about the line from the FD to the T, concentrate only on the line from the WUR to the T.

Tell us if you can follow the return line from the WUR to the T connector. If so, that is the only section you need to focus on. That is the suspected line with a blockage. Fuel from the WUR should be flowing through that line back into the tank. If it isn't, that would account for your control pressure being the same as the system pressure. YOU MUST BEVABLE TO VERIFY THAT THE RETURN FROM THE WUR TO THE T IS OPEN.

[boyt911sc]

[QUOTE=blg5035;9218284]
Please let me know if the flow directions I drew in orange are correct







Ben,

There is a minor mistake in you drawing for the fuel lines (green). The green fuel line from the FD (inlet) should be connected to the fuel filter and not to the fuel accumulator as shown in your post. And the fuel filter is connected to the center fitting of the FA. Side fitting of the FA goes to FP. No wonder you are building up fuel pressure because of these mis-connections. Keep us posted.

Tony

[ossiblue]

[QUOTE=boyt911sc;9218348]

Originally Posted by blg5035

Please let me know if the flow directions I drew in orange are correct







Ben,

There is a minor mistake in you drawing for the fuel lines (green). The green fuel line from the FD (inlet) should be connected to the fuel filter and not to the fuel accumulator as shown in your post. And the fuel filter is connected to the center fitting of the FA. Side fitting of the FA goes to FP. No wonder you are building up fuel pressure because this mis-connections. Keep us posted.

Tony

Tony,

We're there two different ways the WUR return lines were plumbed over the years? I seem to have found that some were plumbed back to the FD relief valve and others were plumbed to a T connector by the firewall. I'm only familiar with the ones with the T connector but on the OP's 80' it may be different. Does this sound possible? If so, I've been misdirecting the OP and am going to bow out and leave this in your capable hands.

[boyt911sc]

[QUOTE=ossiblue;9218362]

Originally Posted by boyt911sc

Tony,

We're there two different ways the WUR return lines were plumbed over the years? I seem to have found that some were plumbed back to the FD relief valve and others were plumbed to a T connector by the firewall. I'm only familiar with the ones with the T connector but on the OP's 80' it may be different. Does this sound possible? If so, I've been misdirecting the OP and am going to bow out and leave this in your capable hands.

LJ,

You could explain the subject much better than me and have the patience. To answer your question, the earlier FD's ('73.5. - '75) have two (2) connections, then to three (3) for '78-'79 (can't recall the '76-'77) and finally to four (4) for '80-'83 SC. The Euro or RoW models slightly vary from the US MY.

I did not find any information about the OP's FD, but my quess would be a FD with three (3) fittings. Delivery, return (FD), and return (WUR). The T- connection you were saying is for the early CIS version (for WUR). In between, there are CIS connections for the WUR and FA at the T-section. The later version for the T-connection is for the FA (fuel accumulator) and the WUR return goes back to the FD.

You are indeed correct to advise him to check the WUR's return line. Whether it goes to the T-connection or not. The cause for the fuel pressure build up has to be determined and corrected. Unless this problem is corrected, I don't see how this engine would ever start or run at all.

Tony

[ossiblue]

[QUOTE=boyt911sc;9218643]

Originally Posted by ossiblue

LJ,

You could explain the subject much better than me and have the patience. To answer your question, the earlier FD's ('73.5. - '75) have two (2) connections, then to three (3) for '78-'79 (can't recall the '76-'77) and finally to four (4) for '80-'83 SC. The Euro or RoW models slightly vary from the US MY.

I did not find any information about the OP's FD, but my quess would be a FD with three (3) fittings. Delivery, return (FD), and return (WUR). The T- connection you were saying is for the early CIS version (for WUR). In between, there are CIS connections for the WUR and FA at the T-section. The later version for the T-connection is for the FA (fuel accumulator) and the WUR return goes back to the FD.

You are indeed correct to advise him to check the WUR's return line. Whether it goes to the T-connection or not. The cause for the fuel pressure build up has to be determined and corrected. Unless this problem is corrected, I don't see how this engine would ever start or run at all.

Tony

Thanks.

Since his car is an 80, my guess is the WUR line goes back to the FD and the T connection is solely for the accumulator. His posts now make more sense to me as I was only familiar with the early set up. Still, the major task now is to be certain the line from the WUR is open, regardless to where it connects.

Ben, sorry for the sidetrack, but I don't want to make your task more difficult by giving you incorrect information. Hope you didn't get confused due to my efforts.

I'm going back to your post #22. From that post, test #3 is the test for the flow through the WUR return line as I now understand it. That test showed fuel flowing out the line when the FP was running and the line disconnected from the FD. That leaves only the internal bores of the FD where the WUR return line feeds into the FD return line, or the WUR itself, as suspects. Could be the pressure relief valve as well, though I am not familiar with how that works with two separate connections at the FD.

From your picture of your FD, here's what I see:



The line/fitting in the foreground is the FD return line. The partially hidden connection behind it--with the banjo fitting and long hex nut--is the WUR return line. Does that sound correct? If so, then the WUR return feeds into the FD body and flows out through the FD return line which is next to it. Your test #3 demonstrated fuel from the WUR flowing to the FD port, which means the line is not blocked.

I'm going to suggest another test, but please ask Tony if this is safe as I've never done it.

Hook up your fuel gauge set to the WUR. Disconnect the WUR return line from the FD as you had done in your previous test #3. Place the disconnected end of the return line into a suitable container. Turn the valve on the pressure gauge so the WUR is isolated from the FD (system pressure measurement.) Start the FP as you previously did and read the fuel pressure from the gauge. Now, open the gauge valve (fuel should begin flowing out the WUR return line.) Does the pressure reading now drop? If so, the WUR is doing its job and the blockage must be inside the FD or with the pressure relief valve. If the pressure doesn't change with fuel freely flowing through the WUR return line, the problem is with the WUR itself, and that can be addressed.

[boyt911sc]

[QUOTE=ossiblue;9218729]

Originally Posted by boyt911sc

Thanks.

Since his car is an 80, my guess is the WUR line goes back to the FD and the T connection is solely for the accumulator. His posts now make more sense to me as I was only familiar with the early set up. Still, the major task now is to be certain the line from the WUR is open, regardless to where it connects.

Ben, sorry for the sidetrack, but I don't want to make your task more difficult by giving you incorrect information. Hope you didn't get confused due to my efforts.

I'm going back to your post #22. From that post, test #3 is the test for the flow through the WUR return line as I now understand it. That test showed fuel flowing out the line when the FP was running and the line disconnected from the FD. That leaves only the internal bores of the FD where the WUR return line feeds into the FD return line, or the WUR itself, as suspects. Could be the pressure relief valve as well, though I am not familiar with how that works with two separate connections at the FD.

From your picture of your FD, here's what I see:



The line/fitting in the foreground is the FD return line. The partially hidden connection behind it--with the banjo fitting and long hex nut--is the WUR return line. Does that sound correct? If so, then the WUR return feeds into the FD body and flows out through the FD return line which is next to it. Your test #3 demonstrated fuel from the WUR flowing to the FD port, which means the line is not blocked.

I'm going to suggest another test, but please ask Tony if this is safe as I've never done it.

Hook up your fuel gauge set to the WUR. Disconnect the WUR return line from the FD as you had done in your previous test #3. Place the disconnected end of the return line into a suitable container. Turn the valve on the pressure gauge so the WUR is isolated from the FD (system pressure measurement.) Start the FP as you previously did and read the fuel pressure from the gauge. Now, open the gauge valve (fuel should begin flowing out the WUR return line.) Does the pressure reading now drop? If so, the WUR is doing its job and the blockage must be inside the FD or with the pressure relief valve. If the pressure doesn't change with fuel freely flowing through the WUR return line, the problem is with the WUR itself, and that can be addressed.

Ben,

Follow LJ's suggested test but disconnect the return line at the WUR side instead of FD side. Why, for better access and easier to control the out going fuel. Use or install another fuel line for the WUR. In short, you will have two (2) fuel lines going into a vessel or container during the test. One line coming from the FD return line used by WUR and a direct line from the WUR outlet or return line. Keep us posted.

Tony

[blg5035]

Tony,

Is this what you are suggesting? I'm not quite certain I understand. The black line is the factory fuel hose and the red is one I provide. I may do it LJ's way with just the factory hose disconnected at the FD, since I feel trying to find metric fuel hose will be more troublesome. When I did test #3 before, I was able to catch the fuel in a bucket (1L Ziploc container).

[boyt911sc]

Originally Posted by blg5035

Tony,

Is this what you are suggesting? I'm not quite certain I understand. The black line is the factory fuel hose and the red is one I provide. I may do it LJ's way with just the factory hose disconnected at the FD, since I feel trying to find metric fuel hose will be more troublesome. When I did test #3 before, I was able to catch the fuel in a bucket (1L Ziploc container).

Ben,

Your diagram is correct. You actually could perform this test using the existing fuel line and place the WUR in a small plastic container to catch the out going fuel. The test is just long enough to get a pressure reading. Remove the two (2) screws that hold the WUR in place and place it a small bucket or container. Detach the return line at the WUR side and secure the fuel line to the container. Once you are ready, test run the FP. Count three seconds and read the gauge. Switch off the FP and repeat.

At the same time, observe if fuel is coming out of the WUR and the detached fuel line (from WUR). While you are there, test the
system fuel pressure too. Post your test results.

Tony

[blg5035]

I did this test. With all hoses connected, system fuel pressure was 5.0 bar. With the fuel line from the WUR return line to the FD disconnected at the WUR and the pressure gage valve closed, system pressure was 4.7 bar. I saw some fuel dribbling out of the return hose which I guess is the source of the 0.3 bar pressure decrease.

When I opened the pressure gage valve and the return line disconnected at the WUR (-069 that Tony provided), the control pressure was ~1.5 bar with the harness disconnected.

I reconnected the return fuel line to the WUR and disconnected the fuel line at the FD. Doing the same test, system pressure was 4.7 bar and cold control pressure was 5.3 bar. This indicates there is some blockage in the line. The part number is NLA according to our host, so I am looking for some hose that can be used.

[mca]

Ben-

I'm in Mount Pleasant. Let me know if I can help in any way. I have a 79 and 82 here in my garage plus tons of extra parts.

Cheers,
Craig

[blg5035]

Originally Posted by mca

Ben-

I'm in Mount Pleasant. Let me know if I can help in any way. I have a 79 and 82 here in my garage plus tons of extra parts.

Cheers,
Craig

Thanks Craig! PM sent

I was unable to find real CIS hose locally, so I went to a hose fitting place and had this made up. They used the original banjo fittings, which Tony has said is the only real important part.



After installing the hose, I checked the fuel pressures. The first time it looked good:

System pressure: 4.7 bar
Cold control pressure: 1.5 bar

I checked it a few more times over a couple days and sometimes I would get similar readings and other times they wouldn't be quite right.

System pressure: 4.7-4.9 bar
Cold control pressure: 1.5, 3.5, 4.25, 5.3 bar

After seeing these, I checked the new fuel line. I disconnected it at the rear of the FD and ran the hose in the bucket. With this setup, the cold control pressure was 1.5 bar as expected. I reattached the hose and tested again and got one of the funny values. I am suspecting there is something wrong with my gages. I have also noticed the fuel that comes out of the gages has a redish tinge, which the fuel going in does not have.

At this point I said screw it and took the gages off and decided to crank the engine. It sustained an idle! However the idle speed is off. Sometimes it is towards 500rpm other times it'll be around 750rpm. It is also smoking out the exhaust. I took a video. When I give it throttle it is maybe 1/4 and held constant. Immediately after I let go of the throttle, it will sound like it is idling nicely then drop back down below 1000rpm and idle rough.

https://youtu.be/gW2e-NWDamY

What has changed from before all this is the WUR and decel valve. I am now using a -069 WUR from Tony and have the vacuum lines connected to the decel valve and thermal valve. Previously the engine had a -009 WUR that does not have the side vacuum port.