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Blueelectron,

First thing is to check the lambda system as already recommended.

That WUR looks pristine.

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Old 10-19-2019, 08:14 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #41 (permalink)
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Quote:
Originally Posted by pmax View Post
Blueelectron,

First thing is to check the lambda system as already recommended.

That WUR looks pristine.
I think the lambda system is working. The shop told me that they checked the O2 sensor and it was not working. They wanted $350 to replace it and I said thanks but no thanks. I replaced it myself last week for a fraction of the cost. After that my idle would fluctuate and hunt up and down. Disconnecting the O2 sensor would stop the hunting. I think because of the very low cold control pressure, the shop had adjusted the mixture too rich and now the O2 system was trying to correct the rich condition. The pulsing idle went away when I turned the mixture down by an 1/8 turn.
Old 10-19-2019, 08:34 PM
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Boxster GT can probably help you with the line you broke.

Since the hot pressures are within spec, I am dubious that you have any obstructions in the return line. Those would raise hot pressure, and yours is within range. Plus it runs fine when warmed up and driven.

Since you report hard cold starting, and have a quite low cold control pressure, why not adjust that? A C clamp might allow you to give it a small nudge. Up-Fixin long ago had an article on how to make the cold pressure adjustable externally. I prefer a different method: drill and tap the iron slug which holds the post. Screw a nut on a bolt (an Allen/inhex is the most convenient)to fit the thread you made. Place a washer over the hole and screw the bolt in until it bottoms. Use an Allen wrench to hold the bolt in place, and a wrench on the nut to pull the slug up. If you do this with the WUR disconnected, but fuel pump connected and your gauge in place, you can see when to stop. If you overshoot, loosen the nut just a bit, and knock the plug down. Because the slug sits below the surface of the housing, you can use the washer trick to raise it. This is a lot easier than trying to drill a hole half into the iron, and half into the aluminum to prevent rotation of the slug (which you can see you don't want, as it will dislodge the stuff inside). You can't do this adjustment hundreds of times, or the friction between the slug and the aluminum housing may eventually get too low to hold the slug. But it isn't a problem if it is only done the few times one needs.

An alternative for lowering the CCP still more is to shim the end of the post internally - less convenient, but same result. But you need to go the other way.

Or you can guess at how much to raise the post with the C clamp or otherwise, and then watch the pressures after everything is back in the car as you try tapping the slug down.

Did you ask the shop if they shimmed the system pressure regulator?

But the WUR looks like a pretty likely suspect for your cold start issues - mixture too rich. The ratio adjustment screw can make mixtures too rich or too lean over the entire RPM/heat range, but don't affect the control pressures.

Your residual pressures look fine, so that's not your hot start problem. So that one is a bit of a mystery, though the fact that the WUR system makes the cold start too rich may make warm starts (the WUR hasn't cooled all the way back down to ambient)iffy.

Others (Tony, for example)who have seen the insides of lots and lots of WURs may have a different view, but the upper compartment is basically sealed against the outside world, so it should look pristine.

And maybe Tony will chime in on what your now measured pressures show.
Old 10-21-2019, 09:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #43 (permalink)
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WUR calibration.......

Quote:
Originally Posted by coomo View Post
DO NOT push out the pin on WUR.You will just upset factory specs,and maybe introduce other issues once this is solved.Take WUR apart, and clean,making sure not to drop top hat.Clean screen.This maybe a cause.


The cold control fuel pressure is already out of spec at this point. Cleaning the screen is good but will only bring the CCP down. You need to get the CCP up. This too RICH or too low CCP to begin with.

Since you have the WUR out, could you post a picture of the top? What is the resistance (Ohms) value of the heater? Keep us posted. Thanks.

Tony
Old 10-22-2019, 03:02 AM
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I have attached a photo of the WUR. The resistance across the terminals is 26.2 ohm. I suspect the shop tried to adjust the cold pressure when the lines were clogged. I can see indentations on the adjustment pin.
Old 10-23-2019, 05:20 PM
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Old 10-23-2019, 05:23 PM
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Cold start valve leaking?

I used 1/8" ID fuel hose to temporarily fix the broken WUR return line and adjusted the cold control pressures. Even now the car takes several seconds to start and is very rich right after starting. The exhaust is extremely smoky and the car doesn't idle without throttle input.

I have bought a wide band O2 sensor to check for lear or rich and waiting for it to arrive.

Is it possible that cold start valve is leaking all the time and flooding. I understand that the Cold Start Valve is hard to reach but can it be tested.
Old 10-27-2019, 09:12 AM
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Loose electrical connection

I was trying to find where the cold start valve is and found this loose electrical connection. Any idea where this is from.
Old 10-27-2019, 10:11 AM
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Backside of the engine. There are 2. One is supposed to be blue, the other green. Problem is when the blue one gets old it turns green. That being said, yours looks pretty green.

One is the air plate safety switch (blue one IIRC). I think the other is the cold start injector.

Anyway, use your left arm and feel around on the backside behind the pope’s hat area and you should find the other end of the connector.
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Old 10-27-2019, 10:40 AM
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Here’s a pic:

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Old 10-27-2019, 10:45 AM
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Originally Posted by tirwin View Post
Backside of the engine. There are 2. One is supposed to be blue, the other green. Problem is when the blue one gets old it turns green. That being said, yours looks pretty green.

One is the air plate safety switch (blue one IIRC). I think the other is the cold start injector.

Anyway, use your left arm and feel around on the backside behind the pope’s hat area and you should find the other end of the connector.
Tim
Is this the air flow switch connection.
Old 10-27-2019, 11:15 AM
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I don’t think so. You have the pope’s hat off. Feel around directly behind the opening on the right in your picture. That is the plunger side that is connected to the fuel distributor.
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Old 10-27-2019, 11:28 AM
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I took another look. The cold start valve is blue and has a blue connection to it. I tried to take a picture with a mirror but wasn’t very successful. The air flow switch is the one that is not connected. Could this cause the rich start condition ?
Old 10-27-2019, 11:34 AM
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It shouldn’t. The airflow switch is designed to cut off the fuel pump in the event of an accident where the engine is no longer running. If no air is moving through the air plate, then a ground shows up on pin 85 of the FP relay and the FP turns off.
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Old 10-27-2019, 12:12 PM
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It shouldn’t. The airflow switch is designed to cut off the fuel pump in the event of an accident where the engine is no longer running. If no air is moving through the air plate, then a ground shows up on pin 85 of the FP relay and the FP turns off.
Oh, that makes sense why the car still runs even with that disconnected. I will proceed with the daunting task of removing the Cold Start Valve/Injector. I can't think of any other reason why the car is flooded during a cold start. The fuel injectors shouldn't be leaking because they are new.
Old 10-27-2019, 12:54 PM
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You said the injectors are new...

Have you done the “baby bottle test” where you pull the injectors and stick them in bottles to make sure they are at the correct opening pressure? Meaning no dripping, relatively even flow from all injectors, etc?

If you bought them from one of the CIS shops (or Tony) they likely did it for you.
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Old 10-27-2019, 01:26 PM
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Originally Posted by tirwin View Post
You said the injectors are new...

Have you done the “baby bottle test” where you pull the injectors and stick them in bottles to make sure they are at the correct opening pressure? Meaning no dripping, relatively even flow from all injectors, etc?

If you bought them from one of the CIS shops (or Tony) they likely did it for you.
I have not tested the injectors. I assumed they would be fine because they were new. IIRC I bought them from our sponsors. The bottle test seems to be less involved than trying to remove the CSV.
Old 10-27-2019, 01:34 PM
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Quote:
Originally Posted by bluelectron View Post
Tim
Is this the air flow switch connection.

Blue,

The black plastic box shown in the picture is not the AFS (air flow sensor) switch. That is the lambda enrichment switch. The throttle body is at left side and AFS or metering unit is at the right side in the picture. Right behind the AFS or metering plate is the switch. Refer to Tim’s picture.

Tony

Last edited by boyt911sc; 10-27-2019 at 02:54 PM..
Old 10-27-2019, 02:49 PM
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Fuel injectors leak?

I pulled all six injectors out and while doing this I disconnected the fuel line at the injectors of cylinders 5 and 6. I was expecting some fuel leak but nothing came out.

When I ran the fuel pump by jumping the relay none of the injectors dripped. The spray pattern was also good when I lifted the plate through the air-box. I let the pump run for some more time and dripping was not obvious.

However, no fuel coming from undoing the fuel line seems suspicious. Is it possible that the fuel lines are fully sealed at the fuel-distribution and that is why they didn't drip. Similar to using your finger to close the top of a straw.
Old 10-27-2019, 02:58 PM
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Fuel delivery........

Quote:
Originally Posted by bluelectron View Post
I pulled all six injectors out and while doing this I disconnected the fuel line at the injectors of cylinders 5 and 6. I was expecting some fuel leak but nothing came out.

When I ran the fuel pump by jumping the relay none of the injectors dripped. The spray pattern was also good when I lifted the plate through the air-box. I let the pump run for some more time and dripping was not obvious.

However, no fuel coming from undoing the fuel line seems suspicious. Is it possible that the fuel lines are fully sealed at the fuel-distribution and that is why they didn't drip. Similar to using your finger to close the top of a straw.


That is NORMAL. A good and properly calibrated FD will not have fuel delivery as long as the plunger is down at rest and the FP running.

Tony

Old 10-27-2019, 08:03 PM
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