Do I need this? (cycle valve)

[mark houghton]

Originally Posted by s5uewf

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...

I was hoping Jim would chime in, as he has tremendous working knowledge on this particular subject (upper and lower chambers and the like).

Emery, I'm suprised that your AFR's don't go as lean as mine when I "unplugged" the freq valve. Also suprised at your idle air correction screw being turned all the way in and still have high idle. Air leak somewhere, one would think.

Jim, thanks (again) for the explanation. I"ve been meaning to balance the flow to the injectors one of these days, so if ever I intend to do without the freq valve, then it would be a must. Meanwhile, she stays plugged in!

[s5uewf]

Mark, maybe the difference in AFR's in our situations is that in my case I removed the entire circuit, and in your situation you left the fuel circuit in place but removed the electricity to the FV? Before I removed my FV completely, I just unplugged it and my engine would lean out when doing that. Removing the device and plugging the connections into the furl head produced different results.

???

As for the air screw I am wondering if with the reduced fuel flow (adhering to JFairman's line of thought) reducing the air at idle would be required to settle out AFR's? But now I have overall less fuel flowing at idle than I should have - so now I have hard starting??

Like I said earlier, still trying to figure this out. CIS test gauges and book will help me as soon as they show up.

[mark houghton]

[QUOTE=s5uewf;4826318]Mark, maybe the difference in AFR's in our situations is that in my case I removed the entire circuit, and in your situation you left the fuel circuit in place but removed the electricity to the FV?
QUOTE]

Could be just that. I'm presuming that no fuel can flow through the FV unless it's powered - in which case it would have the same affect as removing the entire circuit as you did - but I could be wrong.

[e170drvr]

Jim, Thank you! I did not realize there was another adjustment in the fuel head. So I guess the IA guys also adjusted this with the head mod, since it eliminates the lamda valve.
Eric

[e170drvr]

Jim, Is there a spec. that tells you what each individual injector should get, or what we should try to adjust it to?
Eric

[s5uewf]

Just FYI in case it is interesting to anyone. I am also asking a fuel injector supply house if we can still get the injector itself for the FV. In case anyone wants to stay stock and needs to replace. I see Pelican doe not offer replacements.

The injector is a Bosch 280 150 300 as far as I can tell (hard to read).
Some of these are as cheap as $24 apiece depending upon the model. If so, this would present a cheap repair for anyone.

It may be also possible to get a cross match as a substitute (same fuel and electric characteristics). I'll let you know what I find.

From what I can see it is just a screw on fitting to the inlet side and a press fitting on the output side. Should be easy to replicate.

[s5uewf]

I ended up replacing the frequency valve. I found a new replacement on internet for $150 and plugged it in. Once I readjusted the AFR's at idle it seems to be back to where it was before it started acting up.

I also replaced the O2 sensor since I had the car down for repair.

Since it does seem this valve has the capability to cripple the car when it goes belly up, I'd like to know the proper way to remove it from the circuit.

I do have the CIS test gauge now, so can adjust pressures if required.

Does anyone have a procedure or reference I can dig up to give me a set of directions to remove the freq valve and to then adjust fuel head pressure back to where it should be for reliable and normal operation?

Anyway, the goal of my message was just to close the loop and give and update.
Any advice is always appreciated.