Bosch (Volvo) Constant Idle System Instead of AAV & B.C.D.D

[HusseinHolland]

Whilst I've been adding wiring for my AC install, I've also been wiring the Bosch CIS. It was used on Volvos in the mid 80's with K-JET.

V6 version - has correct ECU with 6 cyl ignition pulse. (B) Benzine 2.8l  (F) Fuel Injection    

my wiring

Bosch 0280 220 008 - Leerlaufregler = Idle Control

combined wiring harnesses for AC & CIS

module will be tucked up in right corner

removed the throttle body. Made it easier to access the water housing to redrill & add a 12x1.5mm Timesert for the ECT

Lots of grease on the drill & tap, picks up the shavings

ECT  0280 130 028 (VO 1306024)  installed 

IACV will go something like this. CSV will move to throttle body, where air port is now. CSV port will be used for the IACV return

Flange offset/bolt spacing  is identical. Edit - Volvo uses an o-ring for the CSV - have to check the port ID in the TB

Edited September 27, 2023 by HusseinHolland
additional text, typo

[HusseinHolland]

Coil (-) connection. Red-White, since that's what Volvo uses. Blue is usually (+), glad I checked what Nissan uses for (-) 

Drilled (9/16") & tapped the intake for 3/8" NPT elbow fitting

Made a support plate for the 3517886 IACV. No room for a bolt to come through the plate from above, so I welded a nut on the backside & put in a short stud to retain the IACV bracket. Re-tapped the vacuum port for the charcoal canister to 1/8" NPT & plugged it. The IACV hose passes right over it

Moved charcoal canister vacuum port to rear of plenum, using quick connect with nitrile line

With the IACV placement sorted, I wired the 3 pole connection

and the 2 pole for the ECT, and the ground connections at the intake

CSV placement in TB

to get a clean run on the CSV feed hose, I'm going to flip the CSV. Converting to barb fitting. Using a different CSVB than above, I have 3 (Volvo) variants with differing offset connectors

Made the block off plate for the B.C.D.D, with 3/8" NPT port for the valve cover vent. Used the B.C.D.D base gasket as the template for the mount holes

shaped somewhat, brass elbow fitted. Used HondaBond to seal the plate to TB. 

B.C.D.D port redrilled to match the greater breather vent ID above, since the above port is now dedicated to only idle control

Breather vent elbow fitted below will clear the TPS once reinstalled. Have to figure out a clean way to unify the valve cover port hose with this

78 280Z AAV & Breather vent hose layout for ref.

Edited September 4, 2023 by HusseinHolland
corrections

[HusseinHolland]

Only had about an hour after school today, so I worked fitting the CSV to the TB, and figuring out the VC vent/breather setup to the TB

The Volvo CSV uses an o-ring to seat, rather than a gasket, so I countersunk the hole in the TB to 14mm, to allow an injector o-ring to seat snugly in there

after that I worked on the vent/breather. I couldn't see a clean way to route the hose the long way around, as the factory layout runs, so I doglegged it & I'm running it down to the inside of the TB, clear of the linkage. EDIT - flame arrester is located inside straight section, not at upper elbow 

The thing about doing it this way, the #1 exhaust runner is exposed in that area, for whatever reason Nissan didn't make the pretty extensive heat shield come that far forwards. Since I don't want the vent hose to get crispy in the heat, I made a stainless steel additional shield, attached to the factory one. 5" length, about 2.75" deep, with a 3/4" flange

adding SS M6 rivnuts 

fitted

now the breather is protected somewhat

Edited September 27, 2023 by HusseinHolland
add text

[HusseinHolland]

Minor things after work today. Temps still in the 90's & humid - not pleasant working outside.

Made the harness extension for the CSV & bridge harness for the TPS to incorporate the signal wire to the CIS module.

Next I'll need to pull the fuel injector rail & replace all the fuel hoses. I spent an hour figuring out if I could fit the Volvo FPR pod on the right side near the filter. Not going to work with the existing layout, the angles are all too acute, it would end up stressing the fittings on the pod itself, which is plastic. I'll have to think a little more about that. The only reason I'm bothering is I'd rather rework that while I have the rail off. 

[HusseinHolland]

We have thunderstorms coming in, so I worked on getting the wiring & fuel hoses done so that nothing is exposed, since I have the hood off.

Removed all the fuel hoses. The injector ones were too long - approx 2" - the rail was set such that the FPR was touching the accelerator link arm. Lots of worm clamps 😞

After I replaced the rail hoses with sections of 10mm ID nylon fuel tube I put the rail back in place to measure the injector hose length. I reckoned 1.75" would be more appropriate & not lift the rail

Most everything back together, so now I just need to make a TB gasket, bolt the TB back on, wire a couple connections for the AC in the bay, remove & drain the AC compressor, refill with PAG46, then I can move on to all the wiring under the dash, then get the dash back in (eventually).

[HusseinHolland]

Looking back at the pic of the 78 bay I took, I realized the plug wires were not properly placed - it irked me that they were hanging out on the right side, so I took care of that & made the TB gasket

EDIT - the external throttle return spring had a sleeve of some sort inside it - it was cooked, presumably from the manifold proximity, so I'm not sure of the intent. I removed the scraps & put a section of greased nylon (8mm OD) tubing inside the spring. 

Edited September 10, 2023 by HusseinHolland

[EuroDat]

I havd been following this thread and a little suprised no one has commented yet. It is an interesting mod you're attempting and I hope it delivers the results you are looking for.

Great detail and plenty of photos so others can follow.

Slowly buy surely these parts (AAR for example) are getting harder to find and a possibld update to later more available parts is more than welcome.

 

[HusseinHolland]

On 9/10/2023 at 4:07 PM, EuroDat said:

I havd been following this thread and a little suprised no one has commented yet. It is an interesting mod you're attempting and I hope it delivers the results you are looking for.

Great detail and plenty of photos so others can follow.

Slowly buy surely these parts (AAR for example) are getting harder to find and a possibld update to later more available parts is more than welcome.

 

The thing is, the ECU for this is not readily available, and typically expensive if you can locate one. I'm doing it because I have the components, and my stock AAV is dead anyway.  This will all only be used for a year or so, then I'm putting in a 350Z drivetrain 😁

Weather has been terrible here, so not getting much done. Did a little work on the wiring inside the cabin while it was raining

harness for transistor relay for switching the stock TPS signal to the CIS module to open at idle, ground off idle.

yellow wire is the signal from the TPS, so it needs to go to the relay first, then the switched leg goes back to the module

it will be situated alongside the module. I will need to sleeve the relay

 

 

[HusseinHolland]

Ran the engine today, dash frame with harness in place to check systems

there is a problem with the idle control - idle rpm is way too high for any modulation. Pretty sure there is a passage from the plenum side of the TB back through to the intake via the passages used for the factory BCDD system - openings in bottom area. I thought they were closed off, but too much air is bypassing the idle valve circuit. Pic from when I installed the TB - need to remove it & check the passageways

Edited September 24, 2023 by HusseinHolland
add pic, typo

[Captain Obvious]

32 minutes ago, HusseinHolland said:

Pretty sure there is a passage from the plenum side of the TB back through to the intake via the passages used for the factory BCCD system

Sorry, I wasn't paying enough attention.

On the 280, you can't just slap a plate on the bottom to block off the BCDD. If you do that, you'll have a huge passageway around your throttle plate:

[Captain Obvious]

You can get away with that on the ZX because of the different BCDD design, but on the 280Z, you have to block off at least one of the internal holes.

[HusseinHolland]

10 minutes ago, Captain Obvious said:

Sorry, I wasn't paying enough attention.

On the 280, you can't just slap a plate on the bottom to block off the BCDD. If you do that, you'll have a huge passageway around your throttle plate:

There you have it. I'll remove the plate I made & plug the front side port. Thanks CO!