240 B21ft idle & cat placement

On an '82 with a nearly stock and freshly rebuilt b21ft, I have two things to ask:
1 - I can't get the idle down to 900 while maintaining balance with timing/CO/dwell. And there's no adjustment left on the throttle screw, either.
2 - I'm prepping this car to pass the California smog test, which includes the need for a new cat. This car came to me with a straight downpipe, so cat placement is up to me, however it appears that the factory cat was in the downpipe, itself. According to CA smog rules, do I need to put it back in that location, or can I install it in the standard, underbody location?

No.

There is no idle adjustment. The throttle plate screw is for setting the proper closed position of the throttle plate. The engine has a Continuous Idle System which controls the idle. You want to make sure the microswitch on the throttle bracket is working correctly.

There are Volvo green books on the OZvolvo site that you can download and read the procedure.

You are required to put the converter in the same location in CA. In the downpipe for a B21FT.

Understood.

Here's what I've done so far:

New fuel pumps,
New fuel filter,
Applied WUR mod,
Adjusted all fuel pressures - all within spec,
Checked/adjusted air sensor plate - within spec,
From Greenbook on CIS (Sec2 Grp25), applied direction on setting basic idle speed,
From Greenbook on CIS (Sec2 Grp23), applied direction on setting CO content,
Swapped in a spare idle computer - no change.

Still can't get idle down to 900 unless I pull timing back to zero.

Also noticing it hunting as it idles.

I'm obviously missing something...

It will hunt a tiny bit at idle due to the O2 feedback loop even when everything is working perfectly

Bentley chapter 242 is for CIS . If you go through the procedure and can't get it low enough, I'd guess an air leak or crud-ed up throttle plate or IAC.

I just went through CO emissions in April. Unfortunately, the thread was lost. CO emissions now need to be CA compliant. This means a CARB certified CAT, within 6" of the original location, and the O2 sensor within 1" of original location. (Technically, I fail the O2 location due to using a 90+ manifold instead of the original log manifold, but CO no longer has visual inspection.)

For the CAT, you can get a "direct fit" catted downpipe assembly, or have a muffler shop build one with an approved CAT. For my '85 B21FT, these would be:
MagnaFlow 3321960 Direct Fit California Catalytic Converter, ~$1400 ebay
Walker 81127 ~$370 @ summit

Fitting the generic Walker 81127 into the available space is tight, and requires sharper turns than I'd like. Get a picture of the CAT+downpipe before installation since it's hard to read the numbers once installed.

I've had tough to find air leaks on these engines. The sneakiest one was the broken intake gasket with the break under the number four runner. Also good to do the injector seals if they haven't been replaced in the last three years. Don't buy a cheap intake gasket. They blow out in a matter of months.

Seems like you are well on your way to a good stage zero.

Thanks, guys!

I'm taking a chance and had the muffler shop install it downstream. Reason: CARB's Aftermarket Catalytic Converter Database simply says the location is "UNDERBODY" (searching on VOLVO>1982>245>2.1).

Then, at the smog station, the car didn't show up it the tech's database. According to all he knows, Volvo never made a turbo 240. Got sent to a referee station.

Thanks for the heads up about the comments in the Bentley book. I found one item in their description of setting up idle speed that I've neglected: getting the 0.03mm clearance at the adjustment screw.

Anyone use a squirt bottle to help find vacuum leaks?

Yes, a soapy squirt bottle of water works very well. It will also test your spark plug leads while checking for air leaks with it.

Hammertech said:

I'm taking a chance and had the muffler shop install it downstream. Reason: CARB's Aftermarket Catalytic Converter Database simply says the location is "UNDERBODY" (searching on VOLVO>1982>245>2.1).

Then, at the smog station, the car didn't show up it the tech's database. According to all he knows, Volvo never made a turbo 240. Got sent to a referee station.

Click to expand...

I think you'll be fine on that cat location. I always had my cat under the body in my 240 turbos when I lived in CA and the techs at the typical smog stations never questioned it.

Probably best if you stay away from a state referee though.
Dave B

function wise, having the CAT closer to the turbo outlet will improve heat up times and efficiency at lower power, but once you start driving more spiritedly / at higher power overall (and especially if there's no enrichment to cool the cats) then you'll risk overheating them.

This ignores all the issues of trying to place a catalyst at good angles and with original mounting points since there's not a Volvo official assembly guide that I know of.

Hammertech said:

According to all he knows, Volvo never made a turbo 240. Got sent to a referee station.

Click to expand...

dude

Sounds like you've got a vacuum leak. Check the injectors. That's a good spot

Partial follow-up:

Spent many hours tinkering with the throttle position sensor... I'm happy to report that it idles at 900-950 now. VERY excited! I changed no components from what I had last week. And I was even able to bring the timing up to 12.

If I need to stay away from a referee station, then I'll need to take it to a different smog guy, not the usual. But won't the vehicle database be the same no matter where it take it?

It will just show in the database as previous Fail, the new tech may ask you why and of course he will be very cautious. Nobody wants to pass a car that failed elsewhere.

Enter your vehicle here https://ssl.arb.ca.gov/AftermarketParts/catalysts

and go down to the Walker D-182-65 pdf

The Walker CARB cat for a 240 turbo is 81127.

How many doors you got? You are either a No. 5504, 5506 or 5508






https://ww2.arb.ca.gov/sites/default/files/aftermarket/devices/eo/d-182-65.pdf

In the engine bay the cat lights off faster or works better at idle as mentioned/stays good and hot, but more prone to damage from a blowby motor/oil spitting turbo & more heatsoak in the engine bay.

On the bright side, the cat converter theives/tweakers don't know where to look for it on a stock (location) 240Turbo, so that's nice?

Hammertech said:

Partial follow-up:

Spent many hours tinkering with the throttle position sensor... I'm happy to report that it idles at 900-950 now. VERY excited! I changed no components from what I had last week. And I was even able to bring the timing up to 12.

If I need to stay away from a referee station, then I'll need to take it to a different smog guy, not the usual. But won't the vehicle database be the same no matter where it take it?

Click to expand...

That won't fly set it at 10.

^ Spec is 12 +- 2 ya, 10.000000001* for NOX passing goodness. Hope the springs aren?t too worn in the dist, vac pod works etc.

It?ll put more load on the cooling system and likely be a bit of a slug at 10.

Run on alcohol horrible emissions gas & make sure its hot & running tip top.
Clean oil/intercooler doesn?t hurt either.with minimal blowby sneeze / cleaned out of the airbox & oil separator box working well also helps?wouldn?t want any naughty HCs with old gassy oil huffing around on the dyno in the smog nazi state on the 240Turbo.

Little tiny air leak at the conical downpipe flange right before the kitty cat for redneck air injection but inaudible leak/not enough to mess with the 02 sensor reference air with the cooling fan blowing air backward classic?

Hope the smog guy knows how to drive a stick/doesn?t beat on it (either lugging it in boost/get it running rich or rev the crap out of it and really stir up all the gross oily crankcase windage/light load/ odd timing advance & NOX & has a smooth foot for the gas) or crash your syncros
I?d give them manual cars with great trepidation or watch the screen if they?d let you drive it super smooth cycling on the lambda switch whike watching the screen to maintain target speed/load & drive it myself if they?d let me?(they do in AZ).
Auto so much easier.

So here's what happened since the last post:
1 - The high idle was caused by the idle air valve - not because it was dirty or anything like that, but because the barrel had rotated on the valve, causing the internals to not open/close all the way. (I suppose that's why newer versions are of a one-piece design?) So I rotated the thing until I got the idle speed I wanted, then I JB-Weld'd the top to the barrel. We'll see how long that lasts.
2 - I called the smog referee and was told that in order to schedule an appointment with him, my car had to fail smog first.(?!?!) OK, so I can't get a smog tech to smog my car because their database says that Volvo never made a 240 Turbo, and I cant get a ref to look at my car because it hasn't failed smog. Hmm. Alright.
So I shopped around. Station after station turned me away. Then I got a hot lead on a guy that is said to have a reputation for smogging "old" cars. He was my next stop. And he said 'no problem'. And I asked if he can smog this car 'even if it's a turbo?' He said 'no problem'. I wasn't sure what to do at that point, so I just had lunch.
Did I mention that this is the first time this car has ever been registered in California? As far as I can gather, it's spent it's entire life in the PNW. So I waited for the test results like I was in the delivery room.
And the results are in!
Visual Inspection - PASS!
Sniffer Test - PASS!
I think I can move on with my life, now...