Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

So close, yet so Far: Frequency Valve
Goto page 1, 2  Next
 
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions
View previous topic :: View next topic  
Author Message
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Sun Nov 07, 2021 2:26 pm    Post subject: So close, yet so Far: Frequency Valve Reply with quote

Well Darn it! been messing with the tuning, and I found a leaking vac hose...
Then I heard the Frequencye valve come on (don't think it was related) but when the Freq valve came on the car ran better.... Funny thing is I never really noticed (at least lately) whether it war running or not. But I noticed when I came on, which made me wonder, how long had it not been running?


But then, it stopped working again.
Car was running really lean with out it running. Wires look ok.

So trying to figure this out now.

But one thing I loosely remember, was something that like if I had the mixture to lean? the valve stopped. but I dont remember if was messing with the CIS meter or the WUR. Anyone know about that?

also I have a switch wired to the Fuel pump relay, and as i recall, even with out the key in the ignition, if turned the FP on the FQV would run as well, is that a clue?

(and i cant get it in the garage right now because I have a 968 that won't start in there now!)
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
Fasteddie313  



Joined: 29 Sep 2013
Posts: 2421
Location: MI

PostPosted: Mon Nov 08, 2021 5:38 am    Post subject: Reply with quote

Frequency valve should run whenever the fuel pump is running..

Will run very lean if freq valve is not running like it should..
_________________
80 Turbo - Slightly Modified
Back to top
View user's profile Send private message Yahoo Messenger
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Tue Nov 09, 2021 2:16 am    Post subject: Reply with quote

well thats what happened. so what would stop it from running?

can i just put 12v to it to test it?
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
924RACR  



Joined: 29 Jul 2001
Posts: 8546
Location: Royal Oak, MI, USA

PostPosted: Tue Nov 09, 2021 4:28 am    Post subject: Reply with quote

I think you'd need to PWM it, but that'd maybe be on the ground side? Yeah, wiring diagram seems to ground through the Lambda control unit...
_________________
Vaughan Scott
Webmeister
'79 924 #77 ITB racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Fri Nov 12, 2021 5:35 am    Post subject: Reply with quote

this is wierd, it started working again, then cut out, seems intermittent.

First I just turned the pump on and heard it. then got the car started and heard.

then I heard it about every 1/2 second. I went for a drive and the car was hesitating. But I only drove about 2 miles, when i parked the car went really rich about 9a/f So i assumed it started working again, (since I had previously richend it just to get it enough to drive home from the parts store the day before)

One thing that may or not be related, I wonder is battery voltage? my battery is weak now, and worse since the temps are dropping. I have had to use a jump started to get the car going.


just trying to figure out what direction to go in, its is a part problem, or wiring?
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
924RACR  



Joined: 29 Jul 2001
Posts: 8546
Location: Royal Oak, MI, USA

PostPosted: Fri Nov 12, 2021 11:41 pm    Post subject: Reply with quote

I fully expect it's a wiring problem.

I had issues with my freq valve working intermittently/erratically.

Fix was Microsquirt conversion. Car runs fekking amazeballs now, have been commuting in weather down to 28F without a hiccup.
_________________
Vaughan Scott
Webmeister
'79 924 #77 ITB racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Sat Nov 13, 2021 2:50 pm    Post subject: Reply with quote

Well, remembering that when, I turn the FP and when the battery voltage drops the FV cuts out. and thinking I had a weak battery, well maybe that has something to do with it? So I took the batt to the store they tested it, say the voltage was low, 11.8, but that it tested good, Guy said its probably your alternator.

Would a voltage issue make senes? even if the car was running? I had the alternator tested like year ago.


Also would attaching an LED to the wiring to the FV throw it off? Just so i can see if its getting power or not
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Tue Nov 16, 2021 1:53 am    Post subject: Reply with quote

Well, I don't think its wiring or Basic power/voltage. I fully charged my battery and then took the connections off while the car was running and was still getting 13.4 at idle.

Also (with the car off) I turned on the fuel pump and heard the FV run for a few seconds. SO when I first start the car it was running, but seems after the car warms up then it start to cut out or be intermittent.

after I shut the car off, I turned on the fuel pump again and I hear the FV come on for 1/2 second.

Does the O/2 sensor play a factor? As I know I seem to get rich starts (I think l Have leaky injectors) wonder if I'm fouling the O2? and would that affect the lambda?


Darn, just when I thought I was ready to actually take it on a road trip!!

How do I do any testing on the Lambda?
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Tue Nov 16, 2021 6:50 am    Post subject: Reply with quote

also is the Lambda unit the same in the N/A vs turbo?
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
924RACR  



Joined: 29 Jul 2001
Posts: 8546
Location: Royal Oak, MI, USA

PostPosted: Tue Nov 16, 2021 11:52 pm    Post subject: Reply with quote

Might have to check part numbers for the Lambda ECU.

To be clear - did you check wiring just for the freq valve itself, to the ECU, or all for the ECU? I wonder if it might have an intermittent power or ground.

The lambda O2 closed-loop control should normally be active at idle/low throttle applies, as I understand - when you go high throttle openings, it's supposed to go open-loop. Which means it'll be running a fixed tune, not looking at the O2 sensor return... still modulating the freq valve, but not based on the O2 sensor.
_________________
Vaughan Scott
Webmeister
'79 924 #77 ITB racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
924-76  



Joined: 05 Jun 2006
Posts: 1455
Location: Ontario, Canada

PostPosted: Wed Nov 17, 2021 12:49 am    Post subject: Reply with quote

Unplugging the O2 sensor put the system in safe mode and 50% cycle on the frequency valve making the car running rich.
You could try unplugging the O2 sensor and see what happen. If the frequency valve still doesn't work then you should investigate a wiring issue.
_________________
1976 924 N/A ROW SOLD
1980 931S
1981 931 Part car RIP
Back to top
View user's profile Send private message Send e-mail
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Wed Nov 17, 2021 5:15 am    Post subject: Reply with quote

924-76 wrote:
Unplugging the O2 sensor put the system in safe mode and 50% cycle on the frequency valve making the car running rich.
You could try unplugging the O2 sensor and see what happen. If the frequency valve still doesn't work then you should investigate a wiring issue.


Ill try, I would think though if the wiring/02 were bad (replaced the 02 not long ago) then it would already be in safe mode??

What im confused by it why it seems to run when cold but cut off when warm.

I looked at the wiring from the FV but it goes into a combo wrap in the harness. jiggling it didnt do anything (but it did in my BMW... I saw a spark in the dark....THERE IT IS!!!!)
I jiggled the connections under the dash, made no difference.

Is the lamba the same in the s1 vs s2 (mine is 81/s2)?

what is the likelihood of the Lambda box going bad? Anyone ever repair one?
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Sun Nov 28, 2021 9:32 am    Post subject: Reply with quote

Well I havent been able to test much yet, since I cant get under the car to unplug the O2.
BUT I did borrow a Lambda box From a shop.
so i plugged it in.....and Same result..... BUT I thought this was interesting: So, as before: car starts normally, (A/F between 12-13 then after it warms up for a few minutes, FV stops and A/F goes to 9.8. and the engine is barely running. Then I unplug the second lambda box (while running) and the engine goes back to running better! A/F back to 12-13. Seems like a Clue?

could the thermo time valve be faulty?
what would happen if the O2 Sensor went bad?
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Sun Nov 28, 2021 9:41 am    Post subject: Reply with quote

Thats wierd, Unless im confused. This time the OPPOSITE happened?
Car Warmed up, and when the FV stopped, it went RICH,
Where as before when it stopped, it Went LEAN. WTF??
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
MikeDanger  



Joined: 21 Nov 2002
Posts: 704
Location: Denver

PostPosted: Fri Dec 03, 2021 6:25 am    Post subject: Reply with quote

anyone?
_________________
It was either this or a giant box of legos
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions All times are GMT + 10 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group