I am sorry for asking questions on "BillJams" thread, but I feel they are related to his orig question.

So as stated above in previous post's, If you are not running an O2, then the FV is not receiving mixture info and is really not needed. It's purpose is to get info from the O2, then regulate the fuel pressures to control the actual mixture while the O2 is in the loop. On acceleration/boost, the O2/FV goes out of the loop.

So, if removing the FV, do you need to make any WUR adjustments to compensate for idle and low rpm running? (when the O2 and FV would have been in the loop)

that one above looks like it controls the control pressure instead of the lower chamber pressure.

what makes the CIS go richer when on boost or at WOT?

The default frequence is 50%. If you disconnect the power, the effective frequence is 0% which will increase your control pressure resulting in a lean condition across the operating range. However, you can compensate for this by adjusting toward rich via to CO adjustment therefore successfully omitting the device.

I believe my FV is failing. I have been able to adjust CO at idle to 14.5 AFR. However, if I try to drive my AFR's go up from there.

Disconnecting the FV has no effect (I have already adjsted idle CO) - AFR's still go way lean.

Connecting the FV has no effect - AFR's still go way lean.

This happens when the car warms up and the gauge on the dash is below midpoint. Once the engine warms up to near midpoint, the effect decribed above kicks in.

I see no Pelican replacement FV valves. Anyone know of a source? Should I just call LA Dismantlers, etc. and get a scrap unit?

Or can I actually remove this circuit as pictured above, and then use my utcis WUR and wide band to obtain the AFR I need for smog? Doable or simpler to just replace the FV?

I've been running without mine for years (as well the O2 sensor and everything under the driver's seat). No problems to date.

If I were to remove this valve from the fuel circuit, is the procedure as simple as:

" At "B" there are two hoses connected to the FD with banjo fittings - one from FV and one to WUR.
If the FV is deleted along with its hoses, the port at "A" is plugged and the short banjo bolt used at "A" can be used to connect the single hose to WUR at "B". "

And is this an accurate description of what changes would need to be made to end up with a working fuel circuit? I could remove the underseat DME and O2 sensor later if I wanted, but not necessary.

This does not seem to be a high pressure circuit, based upon the current hoses. I could fabricate my own lines using existing banjos and fittings with new hoses and clamps in between...right?

I didn't have to get or buy anything. Removed the double banjo, removed the FV and used the single banjo from the back I want to reinstall the single line I want to say.

So you removed the END of the FV that goes into the FD with a double banjo, making it a single banjo. What did you do with the other end of the FV that also goes into the FD?

I don't remember Tim. It's been awhile.

It take me awhile to figure it out as I don't think I got any instructions with the fuel head.

Here's what it looks like without it.http://forums.pelicanparts.com/uploa...1249494749.jpg

[QUOTE=billjam;4450425]
If the FV is deleted along with its hoses, the port at "A" is plugged and the short banjo bolt used at "A" can be used to connect the single hose to WUR at "B".[/QUOTE]

Has anybody actually done this? Per the Bentley information:

"The freq. valve controls pressure in the lower chambers of the differential valves. This in turn changes the upper chamber pressure to change the pressure drop and thus changes enrichment".

In an open loop affair - with the freq. valve at a steady 50% duty cycle, this would have a constant effect on the chamber pressures. Change the duty cycle and it changes the effect. If a person were to remove the valve and bypass it with a direct hose connection between the two chambers, you would effectively be mimicking a 100% duty cycle. Conversely, if you were to block off port "A" and redirect the lines as suggested, you would effectively be setting up a 0% duty cycle. Either/or, the end effect would be a change in AFR's that would have to be adjusted out either via an adjustable WUR or with the mixture control screw on the control arm. Would the effect be small enough to allow adjusting back in range?

That's what I did. No problems with the A/F ratios to date. Yes, it could be better, but it's not terrible.

[QUOTE=mark houghton;4818605]

A930Rocket

Join Date: Oct 2003
Location: Mount Pleasant, South Carolina
Posts: 1,440That's what I did. No problems with the A/F ratios to date. Yes, it could be better, but it's not terrible.[quote=mark houghton;4818605]
Quote:
Originally Posted by billjam
If the FV is deleted along with its hoses, the port at "A" is plugged and the short banjo bolt used at "A" can be used to connect the single hose to WUR at "B".[/

Thanks Rocket...I'll take a shot at it one of these days. I just don't like the thought of that freq. valve happily buzzing its life away all the time, just waiting for it to fail me. Delete is the answer.

OK, I just made this mod tonight. I used an M8 fine thread to use as a plug for "A" location and relocated as per the thread for "B" and took the valve out of the loop.

So far:
- Once adjusted, the idle is fine. I have AFR set to 13.8~14.0 at idle for now.
- idle seems smoother than it was prior - perhaps due to failing cycle valve?

Off idle the engine is now lean. AFR up to 15.5 perhaps, but much better and not beyond the 15 range. Only crept around the block since I saw the AFR was lean, but did notice as I put more foot into it AFR's came back down into the 14's and perhaps lower. Still too lean off idle - but much better than prior and steady. I think this confirms my freq valve was acting up.

So, I assume those who have made this mod have adjusted their off idle AFR's via an adjustable WUR of some sort or via a different fuel metering system. Yes?

I will have to tweak my utcis to adjust - believe this will take care of things.

Any advice? Did others notice they had to adjust AFR's beyond simply setting the AFR at idle?

Thanks for the thread - definitely has helped me troubleshoot this issue.

I do plan to now test the valve with voltmeter, etc. to verify its condition.

Did you use some sort of crush washer to seal it?

I was telling Mark that I have a stock WUR. Any changes to the AF were done on the dyno by the factory AF screw.

Yes used a washer to seal it and some loctite on the threads.

Freq valve delete
 

You might want to go back and read this thread first. Lots of discussion on how to delete the Lambda frequency valve between the upper and lower fuel head chambers.

First, a brief history: I have been running with the O2 sensor unplugged for years, but kept the freq valve plugged in (thus, it's always buzzing at the default 50% duty cycle) and simply tuned around it. Everything is cool....

Just for kicks this morning, I pulled the relay in the rear relay tray that powers the freq valve (and probably the whole lambda system as far as I know...but I do know that it stops the freq valve from buzzing). Idle dropped and AFR's immediately went off-scale lean (like 18+). Re-adjusted the idle mixture to about 14.4 AFR, put her in gear and drove off....and the AFR's went to 16.5 before I hit 1500 rpms. Not cool. So, adjusted the idle AFR to 12.0 pig rich, and again a test drive. AFR's topped out at 16 by 2000 rpms. Needless to say, I took it easy and didn't even think about boosting her. Stuck the relay back in, re-adjusted mixture and called it quits.

So the moral of the story: Ya gotta have that damn freq valve buzzing away or it really messes with the AFR's across the spectrum. By shutting off the freq valve,, the upper and lower chambers are no longer linked - simulating a 0% duty cycle (or maybe the opposite...a 100% duty cycle?). Thoughts/comments????

Mark, I tried that also. just unplugged the connection at the FV, and like you it went super lean. Just plugged it back in. So in order to disable the FV we have to physically remove it and reroute the plumbing. This is on my list also.
Eric

Emery, Once you removed the valve, did you readjust the co at the adjustment screw? And still lean? Or did you just remove the valve and not touch the mixture control?
Eric

If you remove the frequency valve you have to increase the 3mm spring tension adjustments under the 6 individual 4mm button head screw covers on the top of the fuel head so more fuel flows through those valves.
The pulse valve is changing pressure up and down on the bottom side of the differential valves which changes the amount of fuel flow through the top side of the valve on the fly while you drive.

The adjustments to the differential valve spring tension has to be done while the fuel pump is on and you're checking fuel flow from each injector into a container that you can measure the fuel level in, like a graduated cylinder.
These 3mm spring tension adjusters are also how you adjust and equalize flow to each injector.

This has nothing to do with the WUR, control pressure, system pressure, or the CO adjustment. It's an area of the fuel head most people are unaware of.

The lambda pulse valve does not link the upper and lower chambers together.
By varying duty cycles (it is an inline electronic fuel injector) it bleeds fuel pressure out of the lower chambers under the differential valves and returns it to the gas tank. That changes the position of the differential valve diaphram and the distance between the metal sealing surface attached to it and the fuel exit orifice in the chamber above it and is the last fine trim adjustment made to the amount of fuel delivered to the injectors with CIS.

When you completely turn off the pulse valve no more fuel is bled out of the lower chambers so even though fuel flows through a tiny orifice #11 in this diagram to get there the pressure will be full system pressure in the lower chamber #9. That will push the diaphram upwards making the passageway that the fuel flows through in the upper chamber smaller which results in less fuel going to the injector. That is why AFR's go lean when disconnecting power from the lambda box to the pulse valve.

This is the only CIS fuel head fuel flow diagram I have seen and saved and some important parts of the fuel head are not in the diagram and some of the labeled parts were not scanned when this file was made, but the upper and lower chambers, differential vlaves and the fuel flow diagram through it with little arrows are all there.
The system pressure regulator and the 6 seperate adjustments for the differential valves are part of the fuel head and are not in this diagram.

The pulse valve and WUR are also left out but they are not physically part of the fuel head anyway.

I hope what I wrote here is understandable... I can describe it very well in person and with diagrams and parts in hand but it is very difficult for me to pluck it out on a keyboard.
http://forums.pelicanparts.com/uploa...1249849080.jpg

Eric, I removed the valve completely and saved it. I plugged the top outlet and replaced the dual banjo fitting with the single banjo fitting on the inlet.

I did leave the wiring in place to the FV and noticed it buzzes for a few minutes after start, then it stops. Since it seems from these threads it should always buzz, I am assuming the valve is bad or the relay. I can always reinstall if required but others imply it is unnecessary and I do not think the Euro 930's use this device...?
I did call LA Dismantlers and they have no used FV's and Pelican offers none...so if it is bad I guess I need to find a way to not use it.

I did adjust the CO using the hex key. I got idle CO adjusted to around 14. I took it for a spin and noticed with very light pedal the AFR's are in the high 14's maybe bouncing into 15 if at all. With any boost the AFR's drop lower ranging downward to the 11's. All seemed "acceptable" except I want the light pedal AFR's to be lower.

Also, I had to turn in the idle air screw quite a bit. Once I got back from my test drive, the RPM's at idle were climbing past 1,000 RPM so I had to turn the idle air screw further - it is turned pretty much all the way in now. So, I obviously still have some sort of issue to solve:

As JFairman said removing the FV would require re adjusting flow within the fuel head. If so, then that would explain what I am now seeing. Though I have reached a reasonable AFR, my idle air is just about closed and my idle speed is higher than I want. Now, this also affects cold starting...It is very hard to start now. Use to jump to life with a bare touch of the key.

I have tested for air leaks around the gaskets, intake, etc. and found none.

So, either I have a fuel restriction (perhaps due to situation JFairman explains), or somewhere else. Or perhaps one of the AAR or AAV or other valves are sticking open and letting in more air.

I ordered a CIS test kit along with fuel filter, sealing washers, CIS manual, ... in hopes I can verify fuel delivery, verify pressures, and assure myself the fuel side is setup right. Then, if things are not settled out, I can walk through the air side of things...I plan to test the AAR valve next - the thing hooked to the intercooler on the right front side via that larger hose...