I just took possession of a 240 wagon that is sick. Here's the story:
I answered an ad for this car, 150,000kk, clean, straight, and two NM owners. Car not driven regularly for a year or so.
nice man drives car 30-40 miles into town, then runs several errands, turning it on and off several times. Then he brings it to my work. I drive car. Sweet, humming, smooth. We change money and documents and because man has no way home that day except the train, I tell him to take the car home and I'll get it in the morning. Now here's when it gets interesting.

He tries to start car, and, no. Finally it starts but will only idle. The second gas is given engine bogs. Then engine revs, with lots of black smoke. Then died when put in gear. I'm laughing hysterically as I now own this sweet, clean, ride that suddenly won't run.

Man calls wrecker, takes car to mechanic. Car runs great. Three days, car never displays any symptoms while mechanic has it, I'm told.

Today I took possession, and car isn't right. At first it was sort of ok, but quickly Idles wrong, too high, missing, strong exhaust smell, sputtering, black smoke with revs. It's drivable, but not right, and not what it was a few days ago. (Not as bad as the initial episode on Wednesday.)

I THINK from reading online, it's a fault in the Mass air fuel sensor, and the guy gave me $80.00 to get one. And $50.00 for a broken tailight lens. He is a decent older man. Not ripping me off. I got the car for a song. Not a spot of rust. Even the paint is nice after 31 years in the desert sun.

Can anyone help me trouble shoot this? I got this car to get to work. It is my only vehicle. I CANNOT get this past emissions testing as it runs. Any ideas or help will be greatly appreciated.
Oh yeah, the cold air flap in the air box was closed when I opened it, though car was warm, but the pipe to the exhaust manifold cowel is corroded and not really attached, so it wasn't getting total scorching air, but not cold fresh air either.
Thanks to you who read this far. ☺

 

The MAFS could very well be the issue, they do act up erratically like that... Does it have an OBD1 box? Not sure about 1988. I wouldn't despair too much, shouldn't be serious.

 

that's the little diagnostic box near the shock tower i read about elswhere? Has a little led you plug in to flash out fault codes? Nope. Not on mine. That came in in 89, I think. There is something forward, nearer the headlight wiring that may be the ECU, but it doesn't fit the discription. Tomorrow I'm going to take the MAFS assembly off and clean it with dish soap....I mean special cleaner, as well as throttle body, and check the accordion hose for holes.

Anything else? Is there an O2 sensor? Or is that what the MAFS does?
It is running rich, for sure. And that is air/fuel, which I can handle. Electrical gives me fits. You modern Volvo guys can have all those on board computers. 😬

 

Funny thing as my 89 740 with 374K on it was starting to run a little rich looking at the tail pipe and during the starting sequence. I never cleaned the MAF and I had started to see cracks in the plastic intake hoses. So I decided to go buy some throttle body , maf and iac cleaner. Sprayed them up and replaced the molded plastic intake system . After that the car starts right up and idles at 1000 rpm until it goes into closed loop and settles down to around 750. Tail pipe cleaned up and car runs great.

 

diag box was LH2.4, which was new in 1989. 1988 was last year for LH2.2

any air leaks downstream of the MAF will cause very erratic ****ty running.

 

Went and bought $30 worth of MAFS cleaner, throttle body cleaner, fuel treatment, ect. Took off MAFS and component parts and cleaned them. fixed 3 tiny holes rubbed into accordion tube with contact cement and steri-strips covered with electrical tape to cushion it until I can buy a new one. All back together, started after some cranking and... it ran the same.

BUT! A clue! As it sat idling, hiccuping, sounding sick, Mr. Bobbles took a half second pause and then smoothed out to a beautiful, beautiful idle. My neighbour and I looked at each other as it happened. It literally changed in a few seconds. This is how it ran when I test drove it! Beautiful!

I suspected that when I got in and gave it gas ,it'd bog, like it did AFTER I'd paid for it. And that's what it did. Idled beautifully until I touched the gas, and then it bogs down or dies. What's that about? Why does it start easy and putter poorly, and the suddenly idle smooth as silk, but won't take a load? I idled it into the garage and shut the door.

Does anyone have any ideas except a new MAFS? I just want to eliminate all possibilities before I spend the big bucks. All the hoses and connections seem correct, as far as my untrained eye can tell. I don't think there are any air leaks downstream of the MAFS, but.....? I'll double check tomorrow morning. Anything I should look for at try would be a huge help.




B

 

88 was the last year for the chrysler ignition control module... the 9(?) pin connector to that module was notorious for being flakey. this module is on the inside of the right fender, just behind the headlight.... its got a vacuum bellow on the lower front corner, and said 9(?) pin connector nearby... you might gently wiggle that cable/connector when its stumbling and see if the behavior changes in any way.

be very careful if you unplug it, do NOT wiggle it side to side, pull it straight off so you don't stretch the pin sockets.

to see if your issue is ignition vs fuel, you also could try hooking up a old fashion timing light to the #1 spark plug wire, and see if the timing is steady or erratic.

 

This is exactly the kind of tip I needed from an experienced guy who knows these older Volvos. I'll try it first thing tomorrow Pierce. I'm excited.
About the timing: I will do as you suggest, but the way it runs so smooth and nice at times, but then super rich makes me think its fuel/air, not spark. By now the plugs are fouled with all that carbon so I planned on pulling them.

I forgot to write something important earlier: there is a big brass inset screw on the MAFS next to the plug. It's clearly (to me anyway) some sort of adjustment screw. But none of the ones I have seen online have this. What is it for?

I also only sprayed the sensors in the barrel. There were four screws on the side where the sensor itself lurks, but after undoing them it didn't pop open with light pressure and I put these back in and left it. I have watched YouTube videos where they take the sensor itself out and spray it, but mine is different from all those and I didn't know if I could dis-assemble mine.
Thanks so much Pierce for your suggestion!

 

you could check also the fuel pressure regulator. pull the vacuum line off it and see if it smells of gas...

 

I pulled the hose off the nipple ad it does smell of gas. This is the only part in the engine that looks new, so it's been replaced.
Is there a way to check it to see if it's failed? I have no fuel pressure gages, naturally, but can a parts store check it? Is there some old school trick lol blowing in the tube?
UPDATE: priced these and holy cow!! They're 70 bucks! Don't want to replace if I don't have to.

 

well usually gas smell in that vacuum line means it's failed so....
might want to check ebay i think they are below $40

 

I took the tube off the throttle body and and sucked in it and the regulator holds vacuum. So,
I did as Pierce suggested and wiggled the wires on the ECM while it was running, and no change. So,
I unplugged the MAFS and he settled into a nice, easy, smooth idle, but bogged with any gas. Plugged it in and back to sputtery, rich idle. I think that's pretty conclusive.

I found a new Delphi MAFS at AutoZone online for 37.00 bucks, along with a 7.00 coupon and free shipping. 32.35 total, and I'm hopeful that will be it.
I'll let you know next week when the part arrives. In the mean time I have other small issues i need addressed, so I'll start a new thread.

 

A new MAFS for $37? Something is wrong.

 

I asked what the deal was when I ordered it. I called beforehand, they looked it up on the stores computer, and that's the price. The picture looks identical to the one on the car. I will let you guys know next week. It's comming from Nashville and will arrive 24th or 25th. They didn't have free 24hour shipping on this partpart, but they do on most other parts.

Like I said, I'll be sure to UPDATE this when I get the thing out on.

 

this is the one I would use.
https://www.fcpeuro.com/products/vol...sor-0986280102

 

only stuff I'd put in my volvo from Autozone is windshield washer fluid, oil, and wipers.

 

Look for a '85-'88 240 in your local junkyards.

Look for a Bosch MAF with the number 0280212007 on it. If you find it buy it for about 50 bucks. Put it on your car... see how your car runs... car runs fine you've done good. Chances are the used maf will be good. Chances are even better that the used Bosch maf will be better than a "new" $37 maf.

There's an '87 at my local jy right now... but I'm in Ohio. And all my redblocks are lh2.4. But every used maf I've bought from jy tested good on my car...3 of them sitting in the basement right now.

 

Greetings if you need fuel pressure regulators i have a bunch all good! Peace and blessings
goldenblock Ga

 

Put the new part in Yesterday, and it works. That problem solved. So yeah, it's not OEM, but for now it's a blessing to get off so cheap.

Now a new problem. I pulled the car out of the garage this afternoon, and it started great and just purred. Shut it off and cleaned the Windows and wiped down the interior, and when I went to start it to put it away, he wouldn't start.

The only thing I did was add some Lucas fuel additive. Never opened the hood, didn't remove the kick panels in interior. Didn't go near the fuses.

Checked the fuses, all seems ok, then I was called into work. Waiting on my boss now. Could the Lucas additive have caused this? I haven't checked that it's getting spark , or fuel flow at the fuel line yet, but it ran perfect 20 minutes beforehand.

It MUST be something simple. Cars don't break in 20 minutes just sitting there not running. Tomorrow I will check fuel at the fuel line and spark at the plugs. Any other ideas are welcome.

p.s. I washed it yesterday, but ran it good before I put it up. And it started today immediately. So I don't think anything got wet.

 

I'd still worry about that $37 MAFS... May be that's all it's good for.