Hello everyone,

I have a 1987 240DL with 100,000 miles on it that I'm trying to get licensed and was nearly stunned with my emissions results.

HC Hydrocarbons = 22.6 (allowed 0.8)
CO Carbon Monoxide = 220.6 (allowed 15.0)
NOx Oxides of Nitrogen = 0.4 (allowed 2.0)

C02 Carbon Dioxide = 241.8 Grams/Mile


Prior to the emissions test I had changed the oil, installed new plugs, wires, cap, rotor, cleaned and reconnected (was disconnected) the flame trap.

I took the test warm with premium fuel and STP Fuel Injector Cleaner in the tank.

The fuel filter looks as if it's never been changed. Couldn't break the bolts loose, PB Blasted 'em and will get it later today.

The catalytic converter appears to be old but does not produce the standard oders or pinging noises of a bad converter.

In addition, the vehicle also has a random stalling issue. It can stall at any time, within a short trip, or later in a longer journey. It can stall repeatedly in a short period of time, or it can run seemingly well for extended periods without stalling at all. It seems to stall most often when either accelerating from a dead stop, or when removing your foot from the pedal to decelerate. It well just shut down as if not getting fuel, or not getting spark.

When it stalls it doesn't usually start up right away. The engine will crank, but again it seems as though it's not getting fuel and/or spark. After some time, say 5 to 30 minutes, the car starts seemly normal and runs seemingly well until it dies again.

While I'm somewhat mechanically inclined I am not a mechanic. I do have a mechanic who's helping me solve the problems.

My question is what could be the likelihood that these issues are related, and where would you recommend looking next?

Thanks in advance.

Fuel Pressure Regulator!

Thanks a lot folks, y'all saved me a bundle.


Peace

Okay...

I'm getting together with the mechanic who's been helping me this weekend, I'll be armed with a new Fuel Pressure Regulator, and a new O2 Sensor (Bosch 13913).

We haven't gotten the Fuel Filter off yet either, so it will also be done. That thing is a superbitch. We given up twice now, though we are being somewhat careful, I haven't the foggiest idea if my local parts store would have any of the parts so we're trying very hard not to break anything in the removal of the filter.

I also have a bottle of contact cleaner for the AMM connector and the ICU connector. If I can find the ECU I want to clean that up as well. And I have a buttload of things that I've printed off Brickboard. The throttle body is going to get a cleaning as well.

I'm planning to be reinspected on Monday, again with premium fuel, and this time, a bottle of Techtron.

I'll let y'all know how it goes.

Many thanks to the community, this place rocks. I was rattlin off all sorts of testing procedures and engine specifications to my mechanic on the phone today and he was all... How the hell do you know all this stuff? BRICKBOARD BABY! LOL, I've owned this car a whole week.

Thanks again, we'll see how it goes.

Peace

Let me just pick everyone's brains for a moment.

What about the ECU?

Granted, most of the ECU issues I've seen on the boards result in complete no-start breakdowns, but I've also seen several stories of issues very similar to mine being the result of faulty or poorly connected ECUs.

Where is the ECU located? I'd like to get the part number off of it, there were apparently several different ECU models used in 87.

Is there a procedure to test if the ECU is operational? I've seen 'tested' ECUs on ebay, what does that entail?

Are the different ECU models interchangeable? If so, is there one that you'd recommend acquiring?

In several things I've read it sounds as if the connector on the ECU could be as likely a culprit as the ECU itself, has that been your experience? Is there something specific you would recommend cleaning the connector with?

High carbon indicates a rich mixture.

Obstructed air intake?

Fuel pressure? Fuel pressure leakdown?
--
Mr. Shannon DeWolfe -- (I've taken to using Mr. because my name tends to mislead folks on the WWW. I am a 51 year old fat man ;-) -- KD5QBL

Also... we did replace the air filter and had the airbox open and the tube to the intake was removed and replaced so it's verified clear of restrictions.

May not help, but my '87 had high CO and HC and low NOX for one of it's tests. When checking everything out I discovered a couple of the terminals in the AMM connector were corroded. I cleaned them and on restest my CO and HC were good but my NOX was high(seems to be very common with '87s). I passed but only by about 2 points. Will do the vacuum advance hose plug trick next year(since the cat is only 2 years old). Might be worth checking.

Cool, nice tip.

Please correct me if I'm wrong but I'm assuming this is the connector on the physical AMM, not a connector from the AMM that plugs into something else?

Is there something specific that you would recommend cleaning the connector with?

Thanks

Yes, I am referring to the connector on top of the AMM. I used contact cleaner. Got it at Pep Boys but any auto parts place should have it. Good luck.

Thanks for the suggestions.

I hadn't really mentioned it but it does run rich. When we replaced the plugs they were black. I had hoped the new ignition components would help in that area but it's doesn't appear to have done so.

I didn't need your last post to know you're running rich - high HC and low NOx was the tipoff there.

My first thought was a leaky injector, but if you've got 4 black plugs that means more than one would be leaking - badly - and that's just not likely. However, something is telling the injection system to deliver a rich mixture. Other posters have siggested checking the FPR, and that's an easy one to do so start there.

Random thoughts - it comes to mind that the '87 is the vintage of the dreaded biodgradable wiring harness. I would make sure the temp sensor (the one that feeds the ECU) has its wires intact, and that its resistance goes down as the car warms up. Also, is the O2 sensor doing its job? Research the archives here to see how to test it.
--
Thank goodness we don't get all the government we pay for. -- Wiley Post

Pull the rear hose off the fuel Regulator and see if you have gas in the hose.If you do then the regulator isn't happy.

It would be a "cheap" fix if it is a bad regulator.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

Please understand I'm new here, and new to Volvo in general. I'm not disputing you in any way, I'm just trying to learn.

I found this at Volvoclub.org.uk

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http://www.volvoclub.org.uk/faq/FuelSystem.html#Fuel_Pressure_Regulator

Effects of FPR Failure. [Tips from Mike W.] When the fuel pressure regulator fails, it either provides full pump pressure to the injectors, resulting in an overly rich condition (I've had two cars do this), or inadequate full pressure, in which case the car will barely run and have no power. This hasn't happened to me personally, but it apparently can. My experience with FPRs pressuring up and giving the engine too much fuel has been that spark plugs will be wet and/or carbon fouled, exhaust will be black and sooty, check engine light will come on, and the OBD will throw codes 113 (fault in fuel injectors) and/or 232 (fuel system compensating for rich or lean mixture at idle). Sometimes,Fuel Pressure Regulator the main fuel pump will even start squealing and get hot to the touch when running. A fairly easy test to see if the FPR is pressuring up too much requires disconnecting the fuel return line (back to the fuel tank) from the rear of the fuel rail. On my 940, this is a simple hose clamp. Be prepared for some fuel to spill. Now get several feet of rubber fuel line hose, slip it over the open end of the fuel rail, and aim it into a gasoline-safe container. Have an assistant start the car, and observe the fuel flow from the hose. You should get a strong stream of fuel, something on the order of 1/2 to 1 gallon per minute. If you get just a trickle or no fuel at all, the FPR is bad. [Tip from Mark Lundell] When you replace the FPR because of a rich burning problem, also replace the little vacuum tube and clean out the intake manifold nipple.

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The symptoms that Mike W. describes in this post do not exactly reflect the symptoms I am having.

The exhaust will occasionally lightly cough some back smoke (usually when starting after sitting... like when leaving the grocery store, but not really in the morings) and there is certainly carbon build-up in the tailpipe, but as a rule, I would not describe my exhaust 'black and sooty' though I do smell gas from the exhaust often.

The engine light doesn't come on when the vehicle dies. The engine light comes on bright when the key is turned on so it appears to be working, but it does not indicate engine trouble when the car stalls.

When we replaced the plugs they were old, black and needed to be replaced, but not wet or entirely fouled.

When running or at idle the car does not seem to be flooding out. The idle does seem to fluctuate somewhat but not greatly and it doesn't die when idling for long periods of time, I let it run about 20 minutes last night just to see.

Okay then...

Do you still believe it could possibly be the FPR?

I've looked around but I can't seem to find a photo or description of where the FPR is located, I did see the mention of the intake manifold. You mention the hose on the rear, will it be fairly clear as to which side is the front and which is the rear?

Thanks to you as well by the way.