Getting 1984 Cadillac El Dorado Biarritz Convertible to pass smog check in CA

[uscmoore]

Hello Forum. I am new to this association. I truly appreciate any help that anyone can offer...

Briefly, I purchased a 1984 Cadillac El Dorado Biarritz Convertible from a close family friend within 3 years ago.  She was elderly and kept the car under a tarp, unregistered for about 9 years. I knew the car was beautiful (original everything) but had no idea if if ran or what it would take to register and get it operable. I took car to a local Cadillac mechanic and we came up with a budget to just get it running.  He was amazing and got everything going on budget. He said I got lucky because the engine was it great working order. When I registered it two years ago plus I had to get it smogged for CA. It passed. And then he went out of business...

That leads me to this post. It had 65,000 original miles at purchase. I have only put on less than 3000 miles since then. It is time to get it smogged again per CA requirements. I didn't think there would be an issue. Well, for example, the CO level allowed in CA is .51.  My car tested at 5.50. That is a not great!

So, long story short, I do not know why it did not pass this year when it did two years ago.  I am hoping for any advice or information on what may be the cause and or how to make sure it can pass CA smog regulations. A new mechanic informed me that he would just be guessing the cause and once he open up the engine getting parts may take weeks and there is no guarantee.  I appreciated his honesty.  I do not have an unlimited budget to solve this problem.  If anyone has been through this before or can offer a more likely direction to look than a simple guess, it would be truly appreciated.

I apologize for the lengthy post.

CMOORE

[James Landi]

CMOORE,

I've owned 5 of these --- 2 convertibles like yours, an Eldorado Roadster, and a Fleetwood.  The 4100 model engine was a highly flawed design, and even when new, rarely made it to 60k miles without some traumatic failure.  So with my cautionary note completed, here are some suggestions... your car has on-board  computer diagnostics. The codes are read using several controls that are part of your automatic digital climate control, so if you have the service manual (or may be available on Google), you can find out what codes are being set and what's wrong.  Because everything on your car is old, even a relatively simple engine sensor could be causing your air/fuel mixture to be far too rich, thus the pollution challenge.  My final suggestion is to put your car up for sale in a national auction for folks who live in states where cars that are 25 years old don't have to meet quality air standards. If your car is in good condition, inside and out, you'll make a lot of money, make someone in another state very happy, and avoid frustration and heartbreak.(I sold my 84 Biarritz for $16,900 in 2006 on Ebay) I know just how lovely these cars are, but of the 5 I've owned, only one made it to 317,000 miles... the other four didn't make it much past that 60k miles without catastrophic costly failures. So sell it 

[Bryan J Moran]

I don't know California laws regarding smog testing but if you have to test this every year it does not seem worth it.  Almost 40 years old, minimally driven as most older collector cars are, it's seems ridiculous to me, here in Iowa. 

It does not seem like you can afford it, if your instructions were to get it to pass smog 'on a budget'.  The reading that failed as James hinted at, is due to running super rich. A mechanic would have to be familiar with the codes and what to do to correct. As you have seen, those folks are not easily found. 

I would expect the repair to cost $5,000 or more, unless a mechanic familiar with the engine can find the issue quickly and it's not an unobtainable sensor. 

[Eric DeVirgilis CLC# 8621]

If neither the "Service Now" or "Service Soon" lights are on, I would have thought the engine is running to spec. Possibly a new catalytic convertor might solve the issue?

[badpoints]

On older cars you can retard the timing to reduce CO2 emissions. A tune up might help.

[smokuspollutus]

We would need to see the smog test of observed vs acceptable levels of the various pollutants to give a specific answer. In the meantime, here are some very simple things to check that can cause a smog failure without tripping a diagnostic trouble code:

With the engine running at idle, does pushing up on the EGR valve cause the engine to stall/almost stall? If not the EGR passages are clogged and need to be cleaned out. (Wear gloves when pushing up on the valve-it does get somewhat toasty being bathed in exhaust gas!)

With the engine fully warmed up at idle, does the EGR valve move when the throttle is opened to about 1/3 or so? Again, wear gloves when feeling for movement from the EGR valve. If not, check condition of all vacuum lines for cracks or breaks. If hoses seem fine, ensure that the EGR valve is receiving vacuum from the solenoid under this throttle open condition. If it is not, check that the solenoid is receiving vacuum from the thermal vacuum switch at all times when the engine is hot. If the solenoid is not receiving vacuum, replace the thermal vacuum switch. If the solenoid is receiving vacuum and is not passing it to the valve, double check all electrical connections to the solenoid and exhaust manifold ground.

Does the smog pump diverter valve blow air into the hose leading to the catalytic converter? With the engine fully warmed up at idle, check the hose for a pulsation of air blowing through it. If you can't feel anything, remove the air cleaner lid and see if you can feel air blowing through the stub hose from the diverter valve. If so, check the vacuum supply from the thermal vacuum switch to the diverter valve-if no supply, replace the thermal vacuum switch. If there is a supply, check electrical connections to the diverter valve and again check the exhaust manifold mounted ground.

Check ignition base timing by disconnecting the green connector behind the distributor. Ignition timing stock is 10 degrees with this connector disconnected...less ignition advance results in less emissions...

Using the climate control panel, enter diagnostics and check that the car reaches operating temperature of 195 degrees/90 degrees Celsius as displayed on the panel. Check that the oxygen sensor status light cycles every few seconds between rich and lean to ensure that the sensor is not lazy. The faster the status light flashes, the better.

There is no post catalytic converter oxygen sensor on this car. If this is an original California car, it came with a large, smooth catalytic converter with a freeze plug looking thing in the bottom of it. These converters rarely fail unless there is something wrong with the smog pump or another major engine issue.

If the car is not an original California car, it came with a catalytic converter with a mesh like exterior. The service life of these are less than the other style but at this age anything is possible. Again we would need to see the results of the test failure to advise further.

[TJ Hopland]

I would not just start trowing parts at it and you can't just 'retard the timing' on cars with computers. Anything that isn't set to spec and wasn't done in the proper sequence can mess things up.  Its basically the same system the trucks used 87-95 so maybe asking shops/mechanics if they have anyone that has worked on those may help finding someone.  Maybe getting your own copy of the official shop manual would help.  Its got all the specs and procedures as well as very good details on the computer stuff. 

The EGR and smog pump checks mentioned above are reasonable tests.  

On a rarely driven car you always have to be concerned about how fresh the fuel is so if it seems to be running well and you still can legally drive it get out and drive it, run that tank out and get some new gas from a busy location.  Since CA doesn't really have much of an off season but in places where they do the volume of premium grade sales goes down in the off season so you could end up buying really old gas at the start of the summer season. This being in CA and a car not requiring premium should not be a factor. 

How is the oil level doing?  Give it a sniff is there any hints of gas?  If something is going wrong that is dumping gas somewhere and its getting in the oil that can cause emissions issues because the gas in the oil can be evaporating and getting into the stream plus its not good for the engine.

A fairly easy test especially since Cadillac spent the extra 20 cents to install a test port is fuel pressure.  If the fuel pressure isn't right (from memory 13 psi) things are not going to be right.  The regulator could have issues where its not regulating or it could be leaking into the intake.  A very common issue with age is the short hose the fuel pump hangs off inside the tank deteriorates so a large amount of the fuel just leaks out inside the tank.  I know from recent experience these will run sort of ok at like 5 psi. 

Since you will have the air cleaner housing off to check the fuel pressure have a look at the injectors.  With the engine not running but cycling the key on and off so the fuel pump runs look at or stick a cloth under the injectors and make sure no fuel is coming out.  If it does the injector could be leaking or more likely on these the O rings in the pods are letting fuel leak out.  If you do have leaking its an easy fix, a throttle body refresh kit is gaskets, o rings, and a new fuel pressure regulator. 

You can then observe the spray coming out of the injectors.  It should be a barely visible mist the only way you can usually tell its there is when it hits the throttle blades.  If you see streams or dribbles they are dirty.

Vacuum leaks are common with age so a close check of all the hoses and devices and the test of going around with something flammable around gasket is worth a try. 

After all that its get the manual and go through the base idle and timing process to make sure thats right.  If its still not working you ideally want a decent scan tool to see what sort of data is coming.  There may be a sensor that isn't right for one reason or another.  Some can be tested not running with a volt meter but its better to look at them live. You can also get some of them to display on the climate control display but I don't recall that being that useful because of how difficult it is to get to each parameter.        

[smokuspollutus]

I agree TJ. However these cars do not monitor total advance, only advance over base timing which is assumed at 10. So for test purposes only, the timing can be safely retarded to see what effect it has on emissions, and of course put back to spec once the repairs are made when it's time for the actual test...

For what it's worth a few degrees advanced past spec is good for an mpg or two and better off the line performance. No ill effects like starter kickback or anything. Depending on the car you might have to step up to 89 octane but the mileage improvement is enough to keep you even as far as cost. This advice is only applicable in an off-road scenario of course...

I would be very skeptical of the test port. In the past few years I have tested fuel pressure on 2 cars using this port and on both the valve stopped sealing and turned into a massive fuel leak. Luckily no fires. One broke immediately after removing the tester and one shortly thereafter on a test drive-the gas smell was so strong I fortunately pulled over and turned the car off in time. Don't know if it would be for all of them but given the age and my 2/2 sample, very very scary. Afterwards I was able to just put in a new core in the valve but the propensity for inferno was just way too scary for me.

[bcroe]

I found on my 79s, putting on a new (monolithic) cat
converter brought emissions way down.  Check out the
timing chain too.  good luck, Bruce Roe

[Eric DeVirgilis CLC# 8621]

I would be very skeptical of the test port. In the past few years I have tested fuel pressure on 2 cars using this port and on both the valve stopped sealing and turned into a massive fuel leak. Luckily no fires. One broke immediately after removing the tester and one shortly thereafter on a test drive-the gas smell was so strong I fortunately pulled over and turned the car off in time. Don't know if it would be for all of them but given the age and my 2/2 sample, very very scary. Afterwards I was able to just put in a new core in the valve but the propensity for inferno was just way too scary for me.

On a throttle body injection car?

[smokuspollutus]

On a throttle body injection car?

Yes. An '81 and '85. The '85 happened in my garage. The '81 happened about a mile down the road on the test drive. I knew what it was right away on that '81 thanks to the '85. Thank God I had the seat covered in a towel, I was able to sop up the gas before it hit the exhaust...and I'm sure the seat was happy it had protection during that!

Probably worth while to carry an extinguisher as our cars age and fuel continues to get reformulated/cut with things no one ever thought we'd be burning.

["Cadillac Kid" Greg Surfas 15364]

Doesn't CA still have an exemption for vehicles licensed as "historical' or an equivalent classification?
Greg Surfas

[Eric DeVirgilis CLC# 8621]

Yes. An '81 and '85. The '85 happened in my garage. The '81 happened about a mile down the road on the test drive. I knew what it was right away on that '81 thanks to the '85. Thank God I had the seat covered in a towel, I was able to sop up the gas before it hit the exhaust...and I'm sure the seat was happy it had protection during that!

Probably worth while to carry an extinguisher as our cars age and fuel continues to get reformulated/cut with things no one ever thought we'd be burning.

Interesting. Engine fires related to FI are usually associated with the earlier (1975-1979) port injected type. Typically this is due to O-ring failure in these. This is the first I heard it happening with TBI. Not disputing anything but how does excess fuel get past the air cleaner/throttle body shield to hit the exhaust?   

[Eric DeVirgilis CLC# 8621]

Doesn't CA still have an exemption for vehicles licensed as "historical' or an equivalent classification?
Greg Surfas

To my understanding, the cutoff year for exemption is 1975 and has not been changed in decades.  It's high time it was.

[smokuspollutus]

Yes, the engine fire issue was almost exclusively 75-80. But that happened even when they were pretty new with the high pressure injection.

In the case of the '81, the fuel was leaking out of the valve past the dust cap. There was fuel pooled on the intake around one of the runners and some running down the back of the block&trans. Fortunately I pulled over on what happened to be a decline and between that and the banking of the road the fuel drip stayed away from the exhaust manifold.

For what it's worth I never had this problem before or since then. Both times I had actuated the valve just prior to the leak so I attribute it to disturbing a really old fitting.

[TJ Hopland]

Interesting, I have not had issues with fuel test ports leaking and I'm sure I have been into plenty of them that have not been touched for years.  Now I know to keep an eye on them after messing with them.  All my cars and equipment have extinguishers.  Never needed one for any of my stuff but have given them to others that had fires going.    Still knowing the fuel pressure is correct is a pretty critical thing to know before doing much other troubleshooting.  If its not right nothing else is going to help and at this age there are tons of things that can make the fuel pressure wrong. 

My experience messing with the timing on any of these cars is you deviate from the proper settings and it tries to compensate with something else which leads to something else and pretty soon the computer is so lost you are lucky that it still runs.

Just remembered another quirk about these cars.  I'm pretty sure they thought the best place for the MAP sensor was inside the car so there is a vacuum hose from the engine to the sensor just for it so lots of places it could be damaged especially at this age.  By this time other GM systems it was on the engine.  If there is anything wrong with the MAP signal its not going to be running correctly.