Okay, well once again I had to take my zcar to work instead of the Volvo. Recently I've been plagued by an intermittent problem, where it doesn't want to rev, or have any power whatsoever. When it first started, I was pulling away from a stop light, after I had been driving fine for over 30 miles and all of a sudden it would not rev past around 1500 or 2000rpm. It seemed like it would cut the fuel passed a certain rpm. I assume because I don't have a tach. So I left it for a while, had lunch across the street, then started it again and it was fine. I assumed it was the mass air flow meter, since the Nissan meters do the same thing when they go bad. Probably a bad decision, but I decided to anyway.

It had been running fine for the last two nights. I drove atleast 50 miles each day with no problems. I thought I had fixed it, but it reared its ugly head again tonight.

So far I've replaced, in the last two months: NGK plugs, new bosch wires, cap & rotor, new ignition coil, fuel press regulator, new gaskets for the intake & throttle body, new stanby fuel pump, main fuel pump, fuel relay, fuel filter, and now a rebuilt air flow meter. The harness shows no signs of damage, not near the firewall or the alternator. All of the vacuum hoses were replaced when I did the intake gaskets. I haven't checked the timing, other than when it was running fine. The timing was set at 12, and the ignition advance computer thing (mounted near the wash. res.) appeared to be working, as the timing would slightly advance when revved. The 25 amp blade fuse, by the battery, is also in fine shape as well.

This post is getting really long, but I could really use some advice on where to go from here. I'm really pissed at my Volvo...it has not been very reliable at all. And it seems the more money and work that I do, the more that things break. Please help...before I decide to give up and sell.

Thanks
Jack

Another thought: If the ignition timing does not advance past 25-30 the engine can't run very fast. Check with timing light and advance the throttle to 2000 RPM or so. The timing should advance well past 30 every time. I had an intermittent failure of the ignition computer just like this problem. A new ignition computer was quoted at about $300 but a used one was $50 to $75. It solved my problem on '83 245.
--
Beastdriver - '75 245 217K miles (Beast), '83 245 216K miles (Beauty),'87 244 DL 160K miles (Dodo)

I have been through a similar journey with my '86. Check out my recent post/thread and responses. It may help.

http://www.brickboard.com/RWD/index.htm?id=735147

Michael

--
1986 240, 230K, Original owner, Boulder, CO.

i had rev problems a while back simlar to what you are describing. problem got progressively worse but was still intermitent. then got worse and worse. it was a bad cat. give your cat a khock or two and try to jiggle it a bit. if no noise then not cat. if rattling is heard, then some piece of the ceramic honeycomb has broken free and is plugging the exhaust line resulting in loss of power.

just a quick easy check. good luck.

-steve in minneapolis
1987 245DL 243k

Jack- hopefully we can come up with an answer before it gets any more frustrating. I've chased a few really annoying ones, particularly with 87's, and I assume it's just a coincidence....
The AMM is a good place to start with this type of trouble. My own opinion of rebuilt AMM's is poor- I know of many that fail again soon after. The airbox thermostat is a possible source of this trouble. I would prefer trying a used 007 AMM to buying a rebuilt- assuming you don't want to spring for new. Note that FCP groton won't sell you new or rebuilt without a new t-stat... that ought to tell you something about the likelihood of related warranty claims.
A related, equally important thing to check is the connector to the AMM. If you look at the pins, they're little 4-fingered things, and with a jeweler's screwdriver you can bend the pins slightly for better contact. Make certain all the pins look like they're at the same depth and are not damaged.
Look at the wiring right in that location too. Check for damage.
Also you must make sure that there are not air leaks in the big hose from AMM to throttle body. Replace if cracked- $14 from FCP. Look for missing or cracked vacuum hoses. Check for vacuum leaks at the manifold gasket and throttle body- any issues, replace.
Also make sure plugs, cap and rotor are perfect- I know you went through it but make sure that they're still good, no fouled plugs. Also, inspect the ignition wiring harnesses near the coil, and under the front pulley to the ignition control unit in the RF fender. I cut the insulation sleeving on mine to inspect one time - my problem was not in that harness but rather at the two-wire grey plug next to the coil. That car was cutting out entirely- a different problem.
GOOD LUCK!
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 225K, 88 744GLE- 209K, 91 244 183K. Also responsible for the care and feeding of: 88 745GLE, 229K, 88 244GL, 146K, 87 244DL, 235K, 88 245DL, 236K

Well, the airbox thermostat has been disconnected since I've owned the car. It has been fine with it disconnected before. So I don't think the problem is there. The car also passed emissions okay last year with it disabled.

I'll look at the harness a little more carefully, and maybe check the torque on the intake manifold bolts when the motor is warm. The piping from the meter to the throttle body is also okay. I checked it when I replaced the manifold gaskets.

I also had a problem with the connector at the distributor as well. However, it ended up being an internal problem with the hall sensor...the part that extends from the side of the distributor. You could nudge on that part, and the motor would cut out. I bought a used distributor and everything has been fine. Also, the wiring going to it, as well as the connector itself, was very well inspected. I replaced the sheaving all the way back to where it splits off into the engine harness.

Thanks for the ideas
Jack

Well, the airbox thermostat has been disconnected since I've owned the car. It has been fine with it disconnected before. So I don't think the problem is there.


The air box thermostat operates a flap. The flap is spring loaded to be open in cold temps and thus allow heated air via the preheat tube to be fed into the intake system, especially the AMM.

If the thermostat fails, the flap stays open all the time. If the thermostat is disconnected the flap could be open all the time. Feeding the AMM heated air all the time will eventually fry its innards.

Check in the air box to see if the flap is open. If you are in southern climes, pull the preheat tube off the exhaust manifold heat shield and let it suck in unheated air. Connect it for emissions testing, they may look for that in your area. They do here.

That whole system is designed to get the cat warmed up and working quicker than without the system. A dealer benefit of that system is that the invisible failure of a $35 part (thermostat) can lead to a dealer replacement of a $400 part (AMM).


Good Luck, and don't give up.

Bob

:>)

is missing. So there is no incoming exhaust flow into the intake. It worked fine before, even in Houston winter, so I hesitate to replace the piping & thermostat.

Jack

It was 1988-1993 that the wire harness was good, you missed it by one year.

I have heard that rebuilt AMM's can still go bad. Not to say you made a bad choice by buying a rebuilt one, but the chance is there.

Have you replaced your air filter? I had a clogged fuel filter cause low accel and crappy starts once. air filter is not much different if clogged. I know it sounds simple, but since you indicated pulling away from a stop, it stumbles...if the ICV cannot pull enough air into the intake until the car gets going fast enough, then you will get crappy accel and low power....*** air has to pass through the filter.....

I am leaning towards that.

--
'88 244 170K, '87 BMW 325e 172K (used to feed a '84 245 'till 227K)

Actually, 1987 was a trasition year for Volvo and their harnesses. Some are good, and some are faulty in 1987.

If you bought a rebuilt Bosch AMM your fine, its the other name aftermarket rebuilt meters that can give you problems.

If the thermostatic air cleaner is stuck inside your airbox to the hot position, (if its getting hot air all the time,) can fry your AMM rather quickly. So you should remove your air box and check. You can put a 16 penny nail trimmed to the right length in place of the moving pintle so you only get cold air all the time. This is the real cause of Bosch AMM failures on 240's.
It is possible that you toasted the second air meter.

Even though your harness looks fine, it could be having problems internally. I can tell you if I had a 1987 240, I would replace the harness. Its not that hard to do once you remove the intake and if you have a u pull it yard near you, you might find one. They are the same from 1985-1987. You can remove the passenger kick panel on the wrecked car and look where it plugs into the fuel computer, if it has a Volvo sticker on it and a part # you know it is a replacement.

I wish I could look at your car for you and good luck.

Yeah, I'm afraid my rebuilt air meter is not a Bosch. It has 'fuel injection technologies' or something on the top cover. About the thermostatic air cleaner, it is disconnected. So the incoming air is always cold. It has been that way since I've owned the car. The ambient temp in Houston is always pretty high, so I figured I was okay with it disabled.

It looks like the general consenus is with the harness. I have a hard time believing mine is faulty, but I suppose thats where I should start. Where should I get a harness? I really hate to resort to searching the bone-yards. And FCPgroton sells new ones for $320? Perhaps I'll inspect my harness really well, cut it open in a few spots and look.

Should I replace the coolant temp sensor in the center of the block? Could this sensor cause any of these conditions?

Thanks,
Jack

Replace the coolant sensor while you have the intake off. Ebay has harnesses for pretty cheap but make sure you buy from a good seller. Some guy has harnesses for sale on the net also, his are pretty cheap.

I had intermittent problems with my 1984 240. To make a long story short, it was the wire harness, a common problem in that year vehicle. Volvo supposedly fixed the wire harness problem by the 1987 model year, but I wonder if that might explain your intermittent difficulties. Have you considered taking the car to an independent Volvo mechanic for a DIAGNOSIS of the intermittent problem? In sunny Kalifornia, that would run about $120. DON'T go to a non-Volvo shop; they don't know Volvos well (I could tell you some horror stories).

Okay, I might try that. I was just under the impression though that you cannot check diagnostic codes, since my '87 is not OBD. You don't happen to know of a reputable shop in the Houston, TX area do you?

Jack

Your description is like our '87 spasms of about 3 years ago. The insides of the (original) Cat came loose, and what didn't blow out the pipe actually formed into 2" diameter ball.

This "cat ball" would randomly roll back and block the exit pipe, then with decelleration(?) come free till the next time. You should hear it move if you smack the cat with the heel of your hand.

I have read several threads on BMW BB about this similar problem....especially on the 5 sereis like my 528i. If the cat goes, it could cause loss of power. Has something to do with plugged pipes, etc. You can test this by sorta 'shaking' the cat...any rattle...then it's time for replacement (percolate also mentioned that this problem could be attributed to the cat).

I think eEuroparts.com sells one for less than $110 with shipping. Have Midas, Monro or any of those monkey joints install it for you. Shouldn't cost more that $60.

I wouldn't rule out bad wiring harness either, but check the cat before you jump into the whole wiring stuff.

Good luck,
SM
--
90 BMW 325is, 98 BMW 528i, 90 Volvo 240DL

It was replaced, probably a year ago. I'll check to make sure, but it looks like its going to be the wiring harness as the top suspect. :(

Jack