posted by
someone claiming to be USF
on
Thu May 20 14:22 CST 2004 [ RELATED]
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I own a 1987 240DL with 150k miles. It is in perfect running condition. My mechanic just installed a new catalytic converter in order to pass a smog test here in Northern California. It failed the first time and after its installation with the following PPM score: 1287 and 1276.
I subsequently brought the car back for his appraisal of the situation. After spending, I assume, a few hours trying to figure out what went wrong, he tested the car twice with a smog machine and it continues to fail. (I don't know the scores of the dry tests).He is stymied at this point.
The mechanic is highly reputable and his shop is recognized by Volvo as one of the best in California. I am to bring the car back next week (May 26th) for additional work. Time is running out and I really don't want to give up the car.
After spending $450 for the catalytic converter -- I am somewhat frustrated that still needs additional repairs.
Any suggestions would be deeply appreciated.
Thank you.
USF
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posted by
someone claiming to be Mike Gambone
on
Thu May 20 14:40 CST 2004 [ RELATED]
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I assume by the numbers you mean it failed NOX (oxides of nitrogen). This is caused by high combustion temperatures. Unless the 87 had a three way cat, changing the cat won't do it. High combustion temperatures can be caused by a lean condition (extra air). So, look for a leak of unmetered air (vacuum leak, intake hose from AMM to throttle body, timing too advanced, and other things that I can't think of at the moment. Most of these guys are just R&R people, they're poor at diagnostics (just my opinion, of course).
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Unless the 87 had a three way cat, changing the cat won't do it.
Uhhhh. All California spec gasoline 200s got 3-way cats in 1977, as did the 49-state four bangers. The 49-state V6s got the 3-way cats in 1979. No competent shop should have put a 2-way cat on (but it's still possible I suppose).
Most Canadian models didn't get them until 85, but the V6s got them as early as 1978.
Most of these guys are just R&R people, they're poor at diagnostics (just my opinion, of course).
Volvo smog work isn't terribly mystifying. If all the shop did was replace the catalytic converter and scratch their heads, it's time to find a new shop. If USF is to imply University of San Francisco, there are plenty of good Volvo shops in the city (and in the Bay Area at large). My recommendations for smog work would lie in Marin however (for matters of my convenience).
To come to any conclusion about the smog results, you'd need to post all the figures you've got. The dyno smog test that was mandated last year should give you results like these:
ASM Emission Test Results
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CO2
(%) |
O2
(%) |
HC (PPM) |
CO(%) |
NO (PPM) |
|
Test |
RPM |
MEAS |
MEAS |
MAX |
AVE |
MEAS |
MAX |
AVE |
MEAS |
MAX |
AVE |
MEAS |
Results |
15 mph |
1692 |
14.71 |
0.09 |
112 |
31 |
35 |
0.72 |
0.10 |
0.09 |
778 |
237 |
768 |
PASS |
25 mph |
1796 |
14.80 |
0.06 |
86 |
29 |
26 |
0.60 |
0.09 |
0.06 |
717 |
199 |
597 |
PASS |
The inverted ones are the ones you want to pay attention to.
If you don't know the last time the various tune-up bits have been changed, do it. That includes vacuum hoses, spark plugs, spark plug wires, distributor cap, distributor rotor, engine oil, air filter, and oxygen sensor.
--
alex
'89 765T, 174,0xx mi
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posted by
someone claiming to be USF
on
Sun May 23 04:17 CST 2004 [ RELATED]
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Dear Alex:
Thank you for your input. I appreciate your interest in my situation.
Here are some other test results:
15 mph: RPM (1798) O2(14.70, 0.68) HC (114, 31, 15) CO % (.73, 0.10, 0.04), NO (PPM) (785, 237, 1287)
25mph RPM (1823), C02 (14.70), 02 (0.63), HC (88, 20, 13), C0% (0.61, 0.09, 0.03), NO (PPM): (724, 199, 1276)
Alex -- I hope this provides some insight.
All my best,
Robert, "USF"
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My first reaction would be that you need a new cat. Usually the ability to conver the oxides of nitrogen into something more reasonable is the first thing a cat will loose. Or they could have installed a two-way cat. I would be very surprised if they did that, but it's not impossible. Certainly there shouldn't be any direct fit two-way cats for the later 240s.
But if the cat is new, and they are an honest shop it would be time to move on.
Check the ignition timing with a gun. The specs should be visible on the emissions info plate on the LH strut tower.
Check the vacuum hoses. Replace any that look cracked.
Check that the oxygen sensor is the right type (three or four wire, not a one wire) and that it's functioning. If it's older than five years, it's probably worth replacing.
Check that the timing marks on the front three pulleys (crankshaft, intermediate shaft, and camshaft pulleys) are where they should be. You'll need to pull the timing belt covers off for this.
Check that the fuel mixture is in spec.
Make sure the car is warmed up. This is more important with the older cars that have a one wire oxygen sensor. The extra wires on the newer O2 sensors are for the heater. If you let the car idle, the exhaust gas will cool off. Without the heater, the O2 sensor can become too cold to function (needs to be about 600F) and the car won't be able to use the sensor to adjust the fuel mixture. When the exhaust gas cools, the catalytic converter will cool off as well (it too needs to be warm to function).
Regardless, now is as good a time as any for a tuneup if you don't know how old the various ignition components are.
P.S. If you register with the brickboard, you can click on the little envelope icon to send me an e-mail. Chances are I'm going to be in the city tomorrow morning/afternoon on Volvo related business.
--
alex
'89 765T, 174,1xx mi
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posted by
someone claiming to be USF
on
Thu May 20 16:06 CST 2004 [ RELATED]
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Dear Mike:
Thank you for your input. I truly appreciate it.
USF
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I recently found the following recap of a thread from alt.autos.volvo. A Google or brickboard search might yield additional info. (You have the "Volvo/Chrysler" Ignition.)
>>Message-ID:
Date: Tue, 2 Apr 2002 21:17:34 -0500
From: "volvo------"
Newsgroups: alt.autos.volvo
Subject: Re: 240 DL can't pass smog
Any 240 that has the Chrysler ignition box will pass NOx with flying colors, provided the cat is at all sound and the ignition secondary is in reasonable condition, when the vacuum hose to the control unit transducer is plugged.
On the dyno and on the street, unless you're really flogging it, you can tell no difference in performance. What happens is that the "limp home mode" for the Chrysler box closely matches a conventional distributor curve; i.e.advance retards 5 degrees when the throttle is opened and climbs with engine rpm to approximately 33 degrees instead of swinging immediately to 52 degrees and backing down to below ping levels.
It's this high sustained advance on the verge of ping that drives NOx high. Typically in this area the NOx reading is just a few points over the allowed limit, and after replacing the converter in drops to just a few points under the limit. But with the transducer hose plugged, you can expect to see a drop of over 400 points on an old converter and as much as 700 points on a new converter.
There was a recall on the 83-84 models to install a vacuum delay valve in the distributor hose (to cancel the retard off idle) and a delay valve in the transducer line from before the throttle (instead of manifold vacuum) to delay the advance curve to quell high NOx readings and satisfy the EPA. I rarely see one of those cars that still has that particular modification intact. There were serious performance issues even on cars in a good state of tune.
By disabling the transducer you gain all the dwell extension features of the lean burn system without sacrificing the marginal at best mpg gains that were so highly touted at the system's inception.
If there were some valid reason to not do this I wouldn't recommend it, however NOx is the most potent pollutant, after ozone, in producing smog in cities and valleys. NOx at high altitudes, according to NASA studies in Hawaii, is more of a destructive catalyst in O3 reduction to O2 than even Cl2F2H (Freon R-12).
Sorry about the rant, I just hate to see people drop 200-300 bucks every two years on a cat that doing it's job extremely well. It's so hard to scrub NOx that one might as well reduce it beforehand in the combustion process if it is at all possible. Air is already 80% Nitrogen so it's impossible to not burn some in an explosion, but if one can keep the temps below the threshold formation value, then why not?<<
Maybe your mechanic would at least give this a try???
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.
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posted by
someone claiming to be USF
on
Wed May 26 13:15 CST 2004 [ RELATED]
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Dear Bruce:
SUCCESS! Your advice worked...
My car passed inspection today (May 26th) thanks to your input. I am truly grateful for your advice. My mechanic, considered one of Volvo's best here in No. Cal., is also appreciative. This will not be his last challenge considering only a few months ago, the State of California strenghtened the emission limits for old cars (mine being an 87, 150K, and a "cream puff"). He anticipates others will have the same problem.
Again, my car failed 2 tests with a new cataltic installed. The new catalytic was removed and replaced with the old and your advice was employed.
Thanks very much -- I don't know how to thank you. At the risk of being cliche, you're a genuius!
Robert aka "USF"
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I have a '92 240 that recently wouldn't pass Ohio NOx emissions (1250 ppm).
I tried all of the things suggested on Brickboard, with no success. I got a waiver after spending over $300 on repairs that did NOTHING, so I can drive my car, but I'd like to fix the problem if I can.
How can I tell if my car has the Chrysler ignition box?
-Schroeck
--
'92 240 Wagon, '92 740 Wagon
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The Volvo/Chrysler ignition system typically has a trademark WHITE distributer cap as opposed to the traditional RED bosch distributor cap that all of us are used to.
If you wnat a reccomendation for a shop in the SF/Bay Area, CRO Volvo in San Rafael is my best bet... can't say enough good stuff about them.
-Flup
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posted by
someone claiming to be USF
on
Sun May 23 10:42 CST 2004 [ RELATED]
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Dear Flup:
Many thanks for your input & mechanic referrel.
USF / Robert
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I will just add:
In San Rafael -- Independent Marin Volvo Saab. The owner is a former brickboarder, and a big 240 fan. I think someone posted a link to pictures of his V8 powered 262C to the 200 forum.
In Novato -- Swedish Auto Service. Good people, and one of the owners of SAS has some ownership of Excelsior Auto Clinic across the driveway. Excelsior does smog work. They know their Volvos quite well.
In Greenbrae -- Mellow Motors. Their courtesy vehicle is a 700 series wagon, and Ric, the owner, is very easy to deal with.
Also in San Rafael, Marin Volvo. Yeah they're a dealer. Yeah they got rid of the Volvo parts guy. But the last time I checked they had a few old timers who knew their 240s pretty well.
--
alex
'89 765T, 174,1xx mi
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posted by
someone claiming to be USF
on
Sun May 23 10:42 CST 2004 [ RELATED]
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Dear Flup:
Many thanks for your input & mechanic referrel.
USF / Robert
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Sorry but 1988 was the last year for the Volvo/Chrysler ignition ('82-'88).
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.
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posted by
someone claiming to be USF
on
Fri May 21 02:16 CST 2004 [ RELATED]
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Dear Bruce,
Thanks very much for taking the time to provide me with your input. I genuinely appreciate your interest. I plan to pass on your recommendations to my mechanic.
Only the best to you.
Robert
"USF"
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