I have a 1986 240 wagon with a B230F that has been losing its engine power slowly over the last year. I can cruise fine on flat ground, but if I try to accelerate, I go probably two mph faster. Going uphill is even worse, if I go into the hill at 50 mph, even if I floor it, I slowly decelerate to about 30. Downshifting also doesn't help much. Just recently, I've replaced the oil, oil filter, spark plugs, and spark plug wires. The catalytic converter has been replaced about two years ago. the PCV system doesn't seem clogged (dipstick stays in it's proper place), although I haven't taken the flametrap out to check. Any suggestions? Doesn't sound like a serious problem, but with it getting worse over time I would like to take care of it before it becomes one. Thank You!

 

First inclination is it could be either air or fuel related. Do both fuel pumps work? You said catalytic converter is 2 years old, was the O2 sensor replaced as well? Any other symptoms other than loss of power?

 

First, are there any other symptoms? Any sights, sounds, smells, hesitation?

Restricted exhaust, air filter, , ignition timing, distributor cap and rotor.

What do your spark plug tips look like?

 

Only other symptoms are slight shaking at idle, along with a small noise that is in sync with the rough idle. Everything looks right to me while watching the engine run. No smells. Spark plug tips were medium to light grey on all four cylinders. Will replace air filter, cap, and rotor next. I'll borrow a timing gun to check timing. I'm not sure how to check the fuel pumps. Not sure if the O2 sensor was replaced. The previous owner had the cat replaced before a year before I bought the car, I've had it for a year now with this being the only problem. Other than my water pump needing to be replaced from age. Thank you guys!

 

Visually inspect your exhaust for breakage especially where it rounds the corner to the rear muffler. Also only use Bosch for the cap and rotor. Wires should be Bougicord. These cars are very particular about what ignition components are used. Can get really funky running issues with other brands.

Edit* assuming your car is Bosch (Orange cap)

Really sounds like an intake or exhaust obstruction, though.

 

I'd take a look at that cat converter. You have to disconnect it and see what power you get then, that's the easiest and cheapest way... and the loudest.

 

Okay, I'll keep all this in mind. I'm out of town until Monday but will check the exhaust, replace air filter, cap, rotor, and get the right brand plug wires (I definitely got the wrong brand). From memory, the distributor cap looked like your standard red cap, not orange. Although I am fairly certain it was Bosch anyway. I'll double check of course.

 

Side note, this engine could have upwards of 300k on it. The odometer has been broken at 215k since I bought it about a year ago. My family has known the previous owner for many years, so I trust when I was told that it stopped working only a few months before the purchase. I got it from an elderly woman that bought it when she was in her mid to late fifties and has not been driving all that much.

 

Also, to disconnect the cat, do I just take it out completely with the remaining exhaust? (Muffler, etc...) or just the cat? Or just unbolt one side? Again, thank you for all your help.

 

instead of disconnecting the cat, you could pull the O2 sensor out, start the engine, and see how much exhaust is blowing out the O2 port vs the tail pipe.


me, I'd do a compression test to make sure the mechanicals are good, then do a base level tuneup (new mann air filter, fresh Bosch distributor cap and rotor, bougicord spark plug wires, and volvo or bosch or ngk plugs), check and set the ignition timing with a timing light (LH2.2 is timed by rotating the distributor), and if all thats good to go, then check the fuel pressure and fuel delivery (if you don't have the proper fuel pressure gauge, bring it to a euro car mechanic who will have the right tools and can do this in 1/2 hour or so).

86 240 should have two fuel pumps, a low pressure 'booster' pump in the gas tank, and a high pressure main pump under the car (about under the back seat) next to the fuel filter. these cars will run OK with a dead in-tank pump as long as the gas tank is 50% or more full, but when it gets down around 1/3rd tank, the main pump will strain to deliver enough gas. My experience was, the power would feel fine then it would bog under heavy load, but your experience could vary.

for sure, a b230f should rev strongly up to near its red line. its only about 115 HP, so uphill acceleration at freeway speeds is weak sauce in overdrive...

 

oreilly loans a fuel pressure guage ($125 deposit) and it has a metric banjo fitting that fits right into the back of the fuel filter.

Poor 240! not enough information to e-diagnose. sorry.

 

Thank you pierce! Seems you help me with my 68 bug on the samba and my Volvo! I'll do all that when I get home on Monday. Thanks to everyone as well!

 

I'm not on samba. my last VW product was a 1989 jetta gli16v I bought new and sold circa 1999 with 250000 miles. my last air cooled VW was a 66 squareback I got rid of in 1984.

 

Oh we'll never mind then haha thank you very much anyways

 

you can also pull the test plug out of the exhaust and go for a drive and see if you get any power back due to a clogged cat.

 

Hey everyone, sorry I'm taking so long to get back. It actually ended up being none of the things mentioned. In the end, it was a bad MAF sensor, which I replaced in five minutes with a refurbished Bosch one. Great power, better mileage, and good low end torque (for a 240). Thanks everyone for your help