960 Injector Assembly Question
 

Greetings! First post; first old Volvo...

OK. Got hold of a one-owner '95 960 with about 4K per year; and complete maintenance records from one end to the other. The car is absolutely immaculate, drives well, and the price was good enough to take a quick chance. After looking the specimen over, I grabbed it for a relative who needed a quick fix for a new highway-based job. Again, based upon the records, the previous (mature) owners took incredibly good care of the car; and all was done by the book.

However, it seems like the injector set is the hands-down noisiest of its ilk I have ever heard. The racket reminds me of a late-70s Subaru with camshaft wobble (memories!). There's also a slight "lean stumble" off idle; and backside analysis tells me horsepower is a bit lower than it should be based upon the numbers. The "service" indicator does illuminate for a while after start (since it's busily running about, I haven't yet had direct access to the car long enough for a lengthy OBD-I "morse" code analysis). MPG figures seem OK; and all is smooth on the highway...

So, is this type of issue known to occur with the 960s @ around 80K or so? Based upon the maintenance logs, it could've been recently stored and had some "mature" fuel passed through the lines; but the current tank contents are no more rank than anything you get "fresh" from the local 7-Eleven.

Just curious before jumping in this weekend...

Great to be here; and thanks again!

So, here's an update. Things have quieted down some clatterwise (lifters, too?).

After 200 miles, highway MPG is now estimated @ 23+. Dead on target for top-condition overall. Smooth running at a level cruise.

However, things still aren't quite right. Think "Briggs & Stratton" run quality with modest loading: Slight stumble at butterfly cracking, and a generalized "vibration" throughout the powerband except during light loading (freeway cruising). As to power, the whole motor lurches reactively @ idle when the AC clutch engages. Overall, more pack mule than thoroughbred performancewise.

The whole picture here is puzzling to me. If the injectors were not atomizing correctly, fuel econ would suffer. Ditto for bad plugs or low firing voltages. Both could cause the stumbly "mower engine" type behavior. Vacuum leaks don't seem to be relevant; as fuel econ is too good, no tell-tale hissing noises are to be heard, and the manifold area appears tight and well-maintained. Timing belt was just replaced last year (2K miles ago). Oh, and apart from a neutral switch code, OBD (A) = 1-1-1 across the board...

Any ideas!?

Thanks a bunch ;)

Injectors do click and they are very loud because of where they are on this car.

Get a can of TB cleaner and clean out the throttle body and idle valve.

Clean flame trap and double check spark plugs.

You need to get your hands on each vacuum line and inspect them all. Pay special attention to where they all come off the manifold, too.

@VDonkey:

Thanks for dropping by. Will be getting to the plugs this upcoming weekend. Decided on some Autolite Double Platinum specimens for the job.

Run roughness increased recently; and there was a concomitant drop in fuel econ. Something in the dark recesses nudged me to disconnect the EGR solenoid for a quick test. After a brisk runabout, the car started to run smoother than it had since picking it up last month (generally normal). If left idling a while, it'll still revert to "mower mode," pointing at a couple of things. We'll see what happens with the Platinums installed...

These are truly the noisiest injectors I've personally experienced; but they're consistent across the rack now. So, all seems OK there.

Vacuum lines: Check. Eyeballs and fingers report back "OK."

Overall, it's a fiddly beast! It brings me back to the old superbike days; where durability and performance were governed by operator intelligence ;)

One thing I will DEFINITELY change is the disposable clamp arrangement on the intake manifold to allow for ready dismantling. It'll probably set me back a few bucks to put together a set of narrow no-pinch reusable units, but this should be worth it in the final analysis; particularly when one considers the overall intake system complexity.

One last question (if you have just a minute more): Who sells internal mechanical parts for this driveline? From what I understand, the transmission shares the bulk of its components with the Toyota Supra unit; but the engine seems to lack any sort of cohesive support, either from the stock or performance vendors. Any "inside" ideas?

Thanks again; and have a great day!

The EGR might be a big clue - don't forget about it - unfortunately my car has no EGR so I can't share any wisdom about it.

I would not use any Autolite or Platinum plugs. You should use the BERU plugs from the dealer, alternatively, Bosch copper 2-electrode plugs. The six plug set from the dealer will be the less expensive among the two, when you get a wholesale price from the dealer (I use tasca.) Let me know if you have trouble digging up part number.

There may be no need to separate the intake manifold from its header. I personally don't like this arrangement, but it seems like it holds up well and doesn't leak even when old. My '98 has not been undone since it left the factory.

The gearbox is indeed an Aisin box and the closest application is some Lexus car. (Here in the usa the "m90" manual box was never available.) Unfortunately I have never done any work on any automatic box so I'm not sure where parts can be reliably sourced from. But I have seen some catalogs on the internet that have listed sets of friction disc things: if I remember right, they lump the Volvo 960 application with other A340 series boxes.

The final drive (diff) seems to be indestructible and the same with the bottom end. I personally would get engine parts from the dealer or from another car.

@VDonkey:

Once again, thank you for sharing. Believe me, I have keen interest in the designed behavior of anything which recycles waste ;) I always was of the mind that food was best eaten the first time 'round...

But I digress --

One last quick question: What is a good range of oil consumption for these motors? I know there is some variance; but, when the car is operated reasonably, is there a characteristic upper consumption limit beyond which we should start sniffing about for trouble?

Thanks again :)

I seem to be losing 1/2 quart every 1000-2000 miles - our engine edging up on 193,000 miles at the moment! I have seen a blue puff at startup once, and I've kept my eye on the tailpipe and haven't seen it since then, so I'm not very worried.

It so happens that none of my current vehicles have an external EGR - I literally haven't had experience with an EGR in over a decade. An OBD2 car would definitely throw a fault code if you blocked it off, but there is a chance that the '95 won't. Some older cars I've worked on had dirty combustion chambers, and I believe, but never proved, that the EGR caused this - I believe a fuel injected car with closed loop mixture control should have clean chambers.