This issue just started yesterday. My car accelerates fine then falls on its face. Seems to happen regardless of engine temperature, RPM, gear, speed, etc. The engine just stops pulling, and while it doesn't stall, it won't rev, but will pop and stumble. If I lift off the throttle for a second or two and go back to power, the engine starts pulling again. The car has had a recent tune up. What should I look at first?

- MAF
- Transfer pump
- Something else?

My first thought was a clogged or broken catalytic convertor. I needed to replace my head pipe so while I was in there I checked and it wasn't visibly damaged on the inlet side. It also doesn't rattle when tapped. I haven't had a chance to pull out my DVOM and test things (the weather turned bad today). I'm stumped.

Thanks,
Jim

 

Try running with the AMM unplugged.

 

I tried driving the car with the AMM unplugged. While it will start and idle but when I tried revving the motor it stalled.

 

Measure the voltage at fuse 4 to make sure the pumps are getting good volatge, should be ~14vdc at idle.

Kinda sounds like a fuel problem, maybe pull a plug to see if its overly rich or lean. Look for any vacuum leaks.

Unfortunately the 85 doesn't have diagnostic codes.

 

Thanks. I'll check the voltage when I get home. My mechanic noted that the car was running lean even when its running "normally".

 

QUICK UPDATE: My mechanic tried a "known good" AMM and took the car for a test drive. It actually ran worse than it does with the existing AMM, but better than when the AMM was unplugged. Weather (and time permitting) I'll tinker a bit over the weekend. If I can't figure it out by next week I can leave the car with my guy for a couple days to figure things out. He confirmed that the transfer pump is at least running. Part of his diagnosis will be the pressure tests.

 

One small note about changing the AMM's - its best to disconnect the battery when doing so since the ECU will adapt to a bad unit over time.

 

This sounds exactly like what my 1981 240 DL is doing.

It's not a real problem thus far, as it loses the drive only momentarily.

The guy I bought the car from said the car has been sitting for many months and in winter, so there is probably humidity in the gas tank and sometimes the engine is getting patches of that hence, cuts out momentarily. He said to go to a gas station and buy two bottles of gas line antifreeze, and it should solve the problem.

I've bought the bottles and put them both in the tank and the problem is still occuring, but maybe it needs a bit more time, since I just put them in about an hour ago.

My car also runs lean by the way, and the owner told me it is the carburetor, and that it needs an adjustment.

Hopefully, what he's telling me IS the case, and in that case, hopefully they are your only problems as well.
I'll update on this when.. there are updates!

 

So.. the power loss has gotten worse. Occurring fairly frequently lastnight while i was out driving. And when it would cut out (engine still running) it would not come back for about 15-20 seconds, instead of the first few times it happened, and it came back after only 2-3s.

Anyway, my newest update, is tonight i got home and tried to start my car... and nothing. Just a little click. The battery light on the dash is lit up while my key is turned and the parking brake and check brakes lights. THe headlights, interior lights, ceiling light, heater fans all operate fine.

It IS pretty damn cold outside right now.. apparently -21 celsius

I'm becoming upset about this situation, as things seem to be getting worse... I'm a total noob to cars I don't know what to do or where to start.
Damn Quebec, CAN has COLD winters.

I have and am currently reading forum thread upon thread and Q&A upon q&a and I find many posts with similar sounding problems (the power loss while driving not the nothing no-start)

I'm reading the owners manual, looking at ordering a shop manual, and searching the internet dry for answers.

Guess I should just take it to a garage.. if it'll start in some less negative degree temperatures.

 

You most likely have the K-Jet FI system since its an 81. www.kjet.org has a lot of good information. How does it idle? You might be loosing fuel pressure as you drive due to a voltage drop to the pump, a pump on its way out, or a dirty filter.

An obstruction in the exhaust (like the cat. converter) can also cause power loss. When this happens you can hear the stuff rattle around going over bumps.

Clean fuses 5 and 7 and and measure the volatge on them while running, should be close to the battery voltage ~13-14 vdc. Look for vacuum leaks, cracked lines.

 

the FI systems are not on teh canadian assembled Volvos which mine is. It definitely has a carburetor.
THe previous owner did tell me that the carburetor does need an adjustment or rebuild.

How do I check voltages? Need to buy a 'Multimeter'? will it come with instructions or will I need to find a thread or something on the net to help me with that? Or if it's really simple, I can maybe figure it out on my own?

I will take it to a shop soon for the carb work, and go from there.

thanks for reply

 

Ok, since it has a carb, disregard all my earlier info. My carb adjustment knowledge is limited to 56-61 Dodges :-)

 

I just got my car back from the shop. The diagnosis is a bad O2 sensor. Apparently it as sometimes sending voltage, which is why it was an intermittant issue, but it was definitely the O2. It was physically broken.

 

the cat conv does get blocked if its idle to long - Q have u checked the Cold Starter ign. switch - ive been told when the volvo runs cold the cold starter kicks in if it does not then the fuel dont mix correct

 

I have a 1987 volvo 240 dl with the same problem wehn i acelerate it will stumble pop and wistile along with some time back fire i checked all the vacume lines and they were fine then checked the seal on the injectors it seemed fine i rechecked the ignition timming and it has gotten a full tune up but when it warms up it continues to do the same thing
Any ideas on wether it could be an o2 sensor, mas, running to lean,or anything ?
"This all started after i replaced the head gasget"

 

My '88 240 Wagon (Patty!) does the same thing and has been doing it for a while now. I wanted to wait til I searched the forums and the 'net for answers before posting. It is the fuel injected B230F engine.

Today was the worst. I was about 2 hrs. from home and it would not accelerate smoothly and would slow down and engine would lose power upon accelerating. It has happened in the past to the point of stalling altogether. It did that today too. Usually, (and as it did today) when I restart the engine, it runs fine until the next time it happens, sometimes weeks later. And for the first time that I have noticed, all the gauges temporarily quit working. Wonder if that was just a loss of ground?

I have replaced the fuel filter and ran the " salesman recommended fuel additives" which did at least give the impression of helping.

I'll look back over this post and try some of the solutions y'all have posted.