Question about solenoid and charge control operation
03-26-11 | 09:30 AM
#1
Thread Starter
Joined: Aug 2008
Posts: 1,149
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From: Miami, FL
Question about solenoid and charge control operation
I've been trying to diagnose some boost problems I've been having on my car for months and I'm trying to fully understand the following operation.
From dave's home page:
Air is supposed to flow between B & C when power is off and between A & B when power is on.
According to the diagrams, the CCA solenoid has pressure applied to port "C", and vacuum applied to port "A". Port "B" is connected directly to the CCA. Now from what I understand, the CCA remains closed below 4500rpm with vacuum applied from the solenoid, and it opens after 4500rpm when pressure is applied from the solenoid.
So according to that, my questions is, is the CCA solenoid then supposed to be powered on all the time below 4500rpm to supply vacuum, and then it's supposed to power off after 4500rpm to supply the pressure?
From dave's home page:
Air is supposed to flow between B & C when power is off and between A & B when power is on.
According to the diagrams, the CCA solenoid has pressure applied to port "C", and vacuum applied to port "A". Port "B" is connected directly to the CCA. Now from what I understand, the CCA remains closed below 4500rpm with vacuum applied from the solenoid, and it opens after 4500rpm when pressure is applied from the solenoid.
So according to that, my questions is, is the CCA solenoid then supposed to be powered on all the time below 4500rpm to supply vacuum, and then it's supposed to power off after 4500rpm to supply the pressure?
03-26-11 | 10:28 AM
#2
The other one
Joined: Aug 2009
Posts: 263
Likes: 1
From: Cols., OH
CCA trouble-shootin....
Do you have a vacum pump. If not your gonna need one especially if you plan on keepin the twins, which are fine.
I'm guessin youve already determined that w/the engine running the CCA rod is pulled all the way in ??
Take your vacum pump and put at least 50-60mmHg to it, if rod doesnt go (pull) into the acturator and stay there the acturator is bad. Make sure there are no tiny rust holes is the actuator. I've seen this on a couple of FD's.
As for the solenoid valve, rod would be pulled in when solenoid is off.
With no power to the sol/valve port A-B NO FLOW / A-C NO FLOW / B-C FLOW.
Now with power/ground A-B FLOW / A-C NO FLOW / B-C NO FLOW.
Also, if tests ok, hook back up to harness, put a long screwdriver tip on it and put the handle at your ear, you should hear it click when engerized, you'll need to use the diagnosis connector and make a jumper tool for that but I doubt thats the problem so dont worry about that one unless necessary.
Check your vacum chamber for leaks too, forgot about that.
I guess its possible the shutter valve itself has an issue, but I havent heard of that to much, but it is possible I suppose.
Hope this helps, sorry I'm a little rusty w/the rats nest, been a while.
I'm guessin youve already determined that w/the engine running the CCA rod is pulled all the way in ??
Take your vacum pump and put at least 50-60mmHg to it, if rod doesnt go (pull) into the acturator and stay there the acturator is bad. Make sure there are no tiny rust holes is the actuator. I've seen this on a couple of FD's.
As for the solenoid valve, rod would be pulled in when solenoid is off.
With no power to the sol/valve port A-B NO FLOW / A-C NO FLOW / B-C FLOW.
Now with power/ground A-B FLOW / A-C NO FLOW / B-C NO FLOW.
Also, if tests ok, hook back up to harness, put a long screwdriver tip on it and put the handle at your ear, you should hear it click when engerized, you'll need to use the diagnosis connector and make a jumper tool for that but I doubt thats the problem so dont worry about that one unless necessary.
Check your vacum chamber for leaks too, forgot about that.
I guess its possible the shutter valve itself has an issue, but I havent heard of that to much, but it is possible I suppose.
Hope this helps, sorry I'm a little rusty w/the rats nest, been a while.
Last edited by KD-93R1; 03-26-11 at 10:31 AM. Reason: Spelling
03-26-11 | 11:39 AM
#3
Here's a cut&paste from a thread I posted on another forum:
Originally Posted by scotty305
Did some more research on the OEM solenoid vacuum lines, ECU pins and control logic. I've always wondered why most (but not all) of the solenoids are OFF at low RPM and ON after the secondary transition. The only exception is the Charge Control solenoid, it is controlled exactly opposite of all the others... ON at low RPM and OFF after the secondary transition. It turns out the vacuum lines for the Charge Control solenoid are plumbed backwards compared to the other solenoids... see diagram below
03-26-11 | 01:18 PM
#4
Thread Starter
Joined: Aug 2008
Posts: 1,149
Likes: 0
From: Miami, FL
Excellent thank you, I've been researching boost problems for months and haven't seen that mentioned which I think should be rather important. And the actual testing procedures of the CCA are also not complete.
