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WUR issues

I have a 3.0 (1983) that has a heck of a time running when I first start it. After it warms up it is fine but it coughs and backfires until it has run a couple minutes. I have done a fuel pressure check and when the engine isn't running I have about 68 psi between the WUR and the head. After 10 minutes I still have about 20 psi there when shut down. The car sat for many years and earlier I drained the fuel tank, changed fuel filter and replaced the air box. The engine seems to run very rich when I first crank it so I am wondering where the idle screw should be set on the throttle body. Does anyone have any suggestions what to do next?

Old 07-12-2012, 06:27 AM
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Quote:
Originally Posted by darklever49 View Post
I have a 3.0 (1983) that has a heck of a time running when I first start it. After it warms up it is fine but it coughs and backfires until it has run a couple minutes. I have done a fuel pressure check and when the engine isn't running I have about 68 psi between the WUR and the head. After 10 minutes I still have about 20 psi there when shut down. The car sat for many years and earlier I drained the fuel tank, changed fuel filter and replaced the air box. The engine seems to run very rich when I first crank it so I am wondering where the idle screw should be set on the throttle body. Does anyone have any suggestions what to do next?
First of all, welcome to the forum. You will find answers to most all of your questions here.

Second, you need to post some pictures of your car before you get "flamed" by the residents.

To your questions.

I have to ask, exactly how did you measure your fuel pressures? Your post is a little confusing but if I understand it correctly, you measured 68 psi between the wur and fuel distributor, shut down the fuel pump and ten minutes later measured 20 psi. Correct? If so, then it sounds like you did not measure the pressure correctly. You have measured system pressure only. Your fuel gauge should have a T valve that allows you to shut off the flow from the distributor to the wur. The valve needs to be open to allow the fuel to flow through the wur and back to the tank. Your pressure should have measured ~1.5 bar (~22psi) with the engine off, pump running, and wur unplugged, depending on ambient temperature. With the electrical connector plugged back in, the wur will heat up and the pressure should rise to ~3.2 bar (~47 psi).

It appears you measured your system pressure (68 psi) and then your residual pressure, after a 10 minute wait (20 psi.)

Your symptoms indicate a possible too high cold control pressure and, possibly a too low warm control pressure. Please re-check your fuel pressures and describe how you set up your fuel gauge. Once that is cleared up and you report back, we can proceed with other diagnoses, if needed.
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Last edited by ossiblue; 07-12-2012 at 07:37 AM..
Old 07-12-2012, 07:34 AM
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DO NOT mess with the small screw on the TB.if you ned to adjust idle, use the big one.

first you need to make sure you dont have any air leaks.

then get good readings on your fuel pressures. you have system pressure, hot control pressure (HCP) and cold control pressure (CCP). remove power from the WUR and check CCP first. you can do it with the engine off and fuel pump running. then connect power to the WUR and check HCP, then do system pressure.

once all that is doen. do a tune up. pllugs, cap and rotor. then have the mixture set/checked.
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Old 07-12-2012, 08:44 AM
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Feedback and reply.......

darklever,

From reading your post, I could deduce that your problem is minor so don't worry and this could be fixed at no time. But the problem/s most OP's have in the past were trying to evade and not answer the questions asked. Since you are doing the troubleshooting, all the pertinent observation and information would be helpful to us.

Please go back and re-read their posts (Larry's and Ty's) and reply accordingly. As we go along the investigation, the culprit/s would stick up like a sore thumb. And refrain from posting information like 'fuel pressure within spec' unless you provided a measurable number, etc. Keep us posted.

Tony

Last edited by boyt911sc; 07-12-2012 at 12:09 PM..
Old 07-12-2012, 10:11 AM
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Sorry I have not replied. I have been out of town on business but will get back to the issue in the morning. Maybe I am misunderstanding the testing procedure buty I hook up my guage to the WUR and disconnected the electric to it and the other end to the fuel distributor. I then, with the key on, lifeted the air flow valve in the air box to let the pump run. Is that the wrong way to do that test? If it is I will do it however I am told in the morning.
Old 07-13-2012, 07:00 AM
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Quote:
Originally Posted by darklever49 View Post
Sorry I have not replied. I have been out of town on business but will get back to the issue in the morning. Maybe I am misunderstanding the testing procedure buty I hook up my guage to the WUR and disconnected the electric to it and the other end to the fuel distributor. I then, with the key on, lifeted the air flow valve in the air box to let the pump run. Is that the wrong way to do that test? If it is I will do it however I am told in the morning.
WRONG WAY
That will cause the injectors to spray fuel into the intake.
If you hold the plunger up for more than a few seconds you'll flood the engine.
You may want to change your oil if you held the air flow valve open for very long.
The correct way is to by pass the fuel pump relay.
Connect 30 & 87A on the relay plug then the pump will run when the key is switched to the run position.
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Old 07-13-2012, 08:33 AM
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+1 on Pete's reply regarding jumping socket 30 and 87 at the fuel pump relay.

More importantly, you did not specify how you tested your fuel pressures and if the gauge you used had a shut-off valve to isolate the wur from the fuel flow from the distributor. As mentioned before, your pressure numbers indicate system pressure, pressure with the valve shut so fuel does not flow through. If, in fact, you connected the gauge set correctly and got the 68 psi reading with the valve open, that would indicate a blockage in the wur or the return line from the wur. If that was the case, however, you car would not only be nearly impossible to start cold, but would not smooth out and run well when warm either.

Please report back on these details, just to let us know how you are doing your tests.
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Old 07-13-2012, 09:12 AM
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better check to see if the frequency valve is working before you spend time on anything else. do a search for that. lots of info.
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Old 07-13-2012, 09:49 AM
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OK< I am enclosing a picture of how I have this hooked up. I jumped the 30 and 87A and turned the key on and with the valve open on the tester the pressure was 68 psi. When I turned off the key the pressure dropped to about 28 psi and stayed there for a couple minutes ans then slowly went down.
The second photo is a mystery to me. It is of the vacuum lines coming from the air control valve and there are two lines coming out. One is attached to the WUR but the other one has a plug in it. Can you tell me where that is supposed to go?
Old 07-13-2012, 01:33 PM
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DAH, I guess the valve should be on the other side of the gauge, right?
Old 07-13-2012, 01:34 PM
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You were right.......

Quote:
Originally Posted by darklever49 View Post
DAH, I guess the valve should be on the other side of the gauge, right?

dark,

The set-up for the CIS gauge is good. But instead of breaking two (2) fuel line fittings like you did, I prefer to connect the pressure gauge at WUR. So I only break one fitting to do the test. BTW, if you had the shut-off valve on the other side, you won't be able to measure the system fuel pressure.

What was your other question about the two (2) vacuum lines? Could you post a picture without twisting my neck looking at it (just kidding). Keep us posted.

Tony
Old 07-13-2012, 02:16 PM
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regarding the vacuum lines. The picture is the front of the throttle body (facing the rear of the car) There are two vacuum lines that come out right behind the air box. One goes to the WUR and the other longer one has a bolt in the end of it and goes no where. Keep in mind, this is a Euro.
Your method of hooking up the guage makes a lot more sense than what I did. I will report back in a few minutes what I get for readings
Old 07-13-2012, 02:34 PM
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I jumped the 30 and 87a as directed with the test equipment hooked up as shown in the above picture. I disconnected the WUR electrical. I turned on the key and the pressure reads 68 psi. It test exactly the same whether I close the valve on the tester or leave it open. Larry said I should have 22 psi with the WUR unplugged and 47 psi with it plugged in. I have nothing like that. Am I missing a step?
Old 07-13-2012, 02:59 PM
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2 vacuum lines, the lower one goes to retard or advance vacuum pod on dizzy (not sure which). Top one to WUR.
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Old 07-13-2012, 02:59 PM
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That's interesting because the one that is hooked up to the distributor comes from the rear of the engine and is plugged into the back side of the throttle body.
Old 07-13-2012, 03:13 PM
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Quote:
Originally Posted by darklever49 View Post
That's interesting because the one that is hooked up to the distributor comes from the rear of the engine and is plugged into the back side of the throttle body.
Everything is cool. The line that hooks to your distributor coming from the back of the throttle body is the vacuum advance hose. That is where it is supposed to connect.

As Timmy2 (Timmayyyyyyyyy) noted, the other line (not the WUR vacuum) is your retard hose which hooks to the distributor vacuum unit as well. It plugs in close to the WUR fitting on the front there.

See pic below from my brand new Coolpix camera. Orange line is the vacuum advance (hooks to the back of TB) and the non connected little tube is the timing retard hose port which ties into the front (rear bumper side). I have disconnected and plugged my retard hose as it helps the car start like it should given 30 years of age on the CIS.

I can get more pics if needed that will show you exactly where the WUR and retard hose plug in.

You are doing fine and in good hands.

Old 07-13-2012, 03:26 PM
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Fuel flow.......

Quote:
Originally Posted by darklever49 View Post
I jumped the 30 and 87a as directed with the test equipment hooked up as shown in the above picture. I disconnected the WUR electrical. I turned on the key and the pressure reads 68 psi. It test exactly the same whether I close the valve on the tester or leave it open. Larry said I should have 22 psi with the WUR unplugged and 47 psi with it plugged in. I have nothing like that. Am I missing a step?


dark,

Your system and control fuel pressures are identical or the same because of a clogged return line or a defective return valve at the fuel distributor (FD). The test is very simple to locate and identify where the blockage occurs. But you would be handling pressurize fuel lines during the test.

The objective of the test is to locate where the blockage is occurring. This is how I do the test. Hook up the CIS fuel pressure gauge with valve close (similar to system pressure test). Break the WUR return line at the WUR side and plugged the line not the WUR outlet.

With CIS pressure gauge valve closed, run the FP. You'll get the system pressure (68 psi). Make sure the plugged return line is not leaking. And place a piece of absorbent rags by the WUR to catch the fuel out flow. Slowly open the shut-off valve and pay attention to the WUR's outlet for fuel coming out. If you have an appropriate fuel line to connect to the WUR's outlet to collect the outgoing fuel (if any) is the correct set-up. Otherwise, an absorbent rags could do the job too.

Open the shut-off valve no longer than a second!!!! Record the pressure drop reading. Repeat one (1) more time. If the pressure gauge registers a pressure drop reading, WUR is not the culprit. And further test downstream is needed. Keep us posted.

Tony
Old 07-13-2012, 05:27 PM
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Yes, your gauge set up is correct. The fact you get 68 psi with the valve open suggests either the inlet/outlet to the wur is plugged or the line from the wur to the return is plugged. In short, you are not getting any control pressure (bleed off by the wur) and that is clear because your pressure reading is the same with the valve open or closed.

There is a small mesh screen in the inlet port of the wur which can get gunked up. You can remove the wur and clean out the ports and see if you get better results. Before doing that, you could also disconnect the line from the outlet port of the wur and connect a short length of line to it and put the end of the line into a jar. Close the valve on the pressure gauge and start the fuel pump. Slowly, open the valve and see if you get a fuel flow from the out let port. If you don't, the wur is gummed up and needs cleaning. If you do get a significant flow, the line to the return is likely clogged.

Edit: Tony posted while I was typing. Jeeze, I guess we are really the same person living simultaneously on two sides of the country!
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Last edited by ossiblue; 07-13-2012 at 05:31 PM..
Old 07-13-2012, 05:27 PM
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Similar 924 CIS problem 1979 car

Similar CIS problem here also. My control pressure is just 3- 4 lbs below my system pressure hot or cold when I hook up my pressure gage. Getting a reading of about 70 lbs control pressure and 73 system pressure. Replaced the wur with 3 know good ones, 2 rebuilt and 1 from another good running car. Can blow through the fuel return line from fuel dist. to fuel tank, and had both wur lines off and they are also clear. Don't know what else to check. Help !
Old 07-15-2012, 09:41 AM
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Quote:
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Similar CIS problem here also. My control pressure is just 3- 4 lbs below my system pressure hot or cold when I hook up my pressure gage. Getting a reading of about 70 lbs control pressure and 73 system pressure. Replaced the wur with 3 know good ones, 2 rebuilt and 1 from another good running car. Can blow through the fuel return line from fuel dist. to fuel tank, and had both wur lines off and they are also clear. Don't know what else to check. Help !
Not to diverge from the original posters problem but, in your case, did you check the pressure relief valve at the inlet to the fuel distributor? Did you ever attempt to adjust the pressures on the wur's by knocking down the pin for cold contol or raising the inlet/out cylinder in the wur housing to see if the pressure dropped?

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Old 07-15-2012, 10:20 AM
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