I thought I'd start a thread on the 242. I'm totally diggin the 242 - what a great car . It's been a long time since I've driven one (my folks had a '76 245 and a '82 244 Diesel) and I had forgotten what a great car they are to drive (the diesel couldn't get out of it's own way). Sure, I've driven Greg's YROG - but that doesn't really count as it's a long way from stock. Totally different from the 122 - the turning radius alone is amazing. The ride is quite civilized (I'm sure I can feel the rear bushings - it's a little mushy) it handles well and while no tire burner - it get's up the hills around here without trouble.

Things that I've done so far - I've got the sun roof screws installed, window handle installed and the drivers seat lowered off the roof. The seats have been swapped around (don't know if Dale did this or if that's the way they were out of the GT they came from). The drivers seat was installed on the passenger side, so the easily adjustable seat base is on the wrong side as it the seat heaters. We'll have to get the seat foam/springs restored. I know it isn't much, but I had to get the alternator and the oil lines fixed on the 122 and played hockey tonight.

Other than that everything works. I was quite surprised when I loaded up my hockey gear and was greated with a lignt that worked in the trunk - mercury switches FTW. Greg and I are getting together to make a list of parts to pull from the car at the PYP.

The idle seems to be skipping a little - could be a plug wire? Seems to even out at higher RPM's...thoughts?

I suspect the lopey idle may be due to a minor vacuum leak around the injectors. I was going to change them but never got around to it. I'm pretty sure I have all the necessary o-rings so maybe we can do that sometime when you're up. It's also a K cam which doesn't idle as smoothly as the rest.

I don't recall messing with the seats. I installed them as I pulled them from PYP or as I got them from Matt. I forget where those seats came from. They have the release levers in the right spot and that's all I looked at.

Look for passenger seat foam. It's usually in good shape.

Glad you're liking it...

WTF are you talking about, Craig? The seatback release is supposed to be on the outside of the car, as is the lumbar support dial and the seatback adjustment dial. It's not a VW, you know... I'm pretty sure those seats were in there correctly, though the BASES might have been in wrong. I think Dale got those seats from me, and if that's the case the driver's seat had it's springs & wire matrix replaced by a sheet metal pan, because I hated the soft bounciness of the stock stuff. The driver's seat butt has a small tear in the orange stripe, right? I know I installed an adjustable seat base in both sides, but I don't know what happened after I gave them to Dale.

Oh, and yes I pulled the busted-ass heater matrix from the driver's seat. I doubt the passenger side seat heater works, but I never tried it.

Cool, we can swap steering wheels and have a quick look at the injectors. 100 words or less lesson on how all this stuff works - I got the jist of it from the session in Greg's garage, but there are some parts that need review. I should scan eBay for a Haynes.



All the adjustments are in the right place, but the bolt adjustable seat frame (passenger) is on the drivers side and the easily adjustable seat frame (handles) are on the passenger side. When we go to the PYP I may pick up some seats to scavenge foam and another ajustable base. You can change the backs of the seats relative to the bases - but come to think of it that would be more difficult than changing the seat frame. To my eyes the passenger seat bottom looks more warn (there is a burn mark in the passenger seat) to me.

I've got dual handle adjustable seats in the 122 - so I should put them in on both. If I could find a good heater matrix I'd add it as well. There never was heat to the passenger seat - let them freeze I say.

Oh and the trunk room is brilliant - so much better than the beetle. We can go camping in this car, I'm sure of it.

...and you can probably sleep inside with more comfort also

Yes, changing seat frame bases is far easier than changing seat backs! If those were my seats (do you see springs & stuff under the butt cushion, or a steel plate?) I *may* have had the bolt-down frame under the driver because it's nearly never adjusted, since I'm always in the driver's seat. Set it and forget it. I thought I had the adjustable ones under both seats, though.

just pick up/order a haynes from crappy tire, $14.99 or something. hardly worth ordering over the net and dealing with shipping. bentley, on the other hand, is a little trickier, although a haynes is probably all you need for the basics, the rest all the k-jet gurus are your best resource.

100 words or less? Unpossible, but here's the basics:

Fuel from the tank is delivered by an in-tank pump to the main pump, which pressurizes the fuel accumulator and the rest of the system. The accumulator (the little thing sitting next to the main pump) stores a volume of fuel under pressure and this is kept in reserve for all sorts of things. Between the main pump and the accumulator is a check valve, to keep pressure in the system which reduces vapour lock on hot starts.

Out of the fuel filter (on the firewall), the fuel line goes to the fuel pressure regulator on the fuel distributor. This valve regulates the fuel pressure to 75-80 psi (the pump is capable of over 150 psi), and then this fuel is split to several circuits.

The first circuit is the injector circuit: the fuel goes to the side of the metering barrel valve, which is lifted by the airflow plate and allows a measured amount of fuel past the valve based on how much the airflow plate is lifted. The fuel passes into four separate circuits, where within each circuit the fuel squeezes between a jet and a thin stainless plate (more on this later), through the injector lines, and out the injectors. The injectors will not pass fuel below 20-30 psi, and above this they snap open and allow fuel to flow past an oscillator which breaks up the fuel into really small droplets.

The second circuit is the fuel trim cirucuit (Lambda-Sond cars only): Below that thin stainless plate I talked about earlier, another quantity of fuel passes through a small jet and fills up the cavity beneath, which provides pressure up against that plate. In cars equipped with Lambda-Sond (oxygen sensors), fuel pressure is bled off from underneath this plate by what's referred to as a "frequency valve". In bleeding off more fuel from under the plate, pressure under the plate is reduced (because it can't flow through the inlet jet fast enough) and the plate is allowed to bend down, allowing more fuel to squeeze between it and the jets above the plate. I'm fairly sure the non-Lambda cars don't have this circuit at all, but the turbo car certainly does.

The third circuit is the control pressure circuit: Also called a warmup circuit, a flow of fuel is metered to the top of the metering barrel valve and on to the control pressure regulator, where it's regulated down to about 30-40 psi for warmup, and gradually increases to 50-60 psi for operating temperatures. This pressure works on top of the metering valve and restricts the amount of lift, varying the amount of fuel delivered for a given flow of air. The control pressure regulator has a bi-metallic spring and a heating coil, and is fed 12v to heat the coil and bend the spring, increasing control pressure for operating temperatures. '81-'83 Turbo cars have another method of controlling control pressure, through a complicated dual-dashpot vacuum arrangement, alongside the bi-metallic spring and heating coil deal. '84-'85 turbo cars use another method to achieve the same results.

There is also a warmup air regulator, which is another bi-metallic spring thingie, opening a small orifice that feeds more air to the engine when open. Another heating coil is included, fed constant 12v power, and it also picks up heat from the valve cover & engine.

The wiring is another Escher-esque deal: The starter solenoid has a contact that's specifically for bypassing the ballast resistor and feeding the coil a full 12v during cranking. Meanwhile, the starter solenoid trigger circuit is also providing power to the Thermal Time Switch, buried in the cooling passages in the head. The TTS passes current IF the TTS is not warmed up by either the coolant or the current passing through it. If the coolant temp is too high, the TTS will not pass power, and if current flows through the TTS for too long, the TTS opens circuit. The TTS is used ONLY for the cold start injector. Constant 12v power is delivered to the control pressure regulator and warmup air regulator whenever the ignition is turned on, so leaving the ignition turned on for any length of time before starting the car (cold) can give you some headaches.

The momentary grounding of the ignition coil drives the tach, and it also drives the fuel pump relay. The relay will operate on the alternating on/off current from the ignition coil, which closes not one but TWO circuits within the relay. These two circuits each operate one of the fuel pumps. Why not use one circuit for both pumps??? Anyway, there's also a pair of fuses for this deal, and for some reason if you jumper both fuses together, both fuel pumps will run.

Fuel Pump Relays are notorious for failing without warning - sometimes they'll come to life again when they cool down, but sometimes not. Keep a spare in the car. You can easily fix them by pulling them apart and reflowing the solder on the main power connection - you'll see which one it is by the burned, cracked appearance.

In-tank pumps can die without crippling the car, but frequently you'll start to run worse and worse below half tank when they do die. You can usually drive the car very gently, but any time fuel delivery requirements go up, the car will momentarily shut off.

Main pump check valves, fuel pressure regulators, control pressure regulators, or even the frequency valve can leak, causing the fuel pressure to slowly (or quickly) drain away. If the engine is hot at this point, the fuel in the injectors is boiled away and the long, skinny lines fill up with vapour. When you try and start the car again (between 15min and 2hrs of shutting down hot), it will crank and crank and crank, and maybe 1 or 2 cylinders will fire until enough fuel is flowed to the injectors to purge the lines. By the time the engine cools down, the fuel will condense back to liquid and the lines usually siphon enough fuel back into them so that the car starts perfectly when cold.

Injectors sometimes clog up, airflow plates get dirty, and the fast idle air regulator can clog up or the hoses to/from it will crack. Injector seals leak, not only between the injector and the phenolic spacer but between the spacer and the head as well. These are goofy sizes, and you really need Volvo parts here (or a tube of RTV).

The warmup air regulator can also get very dirty and sticky, and stop working. It can also freeze, and will usually freeze in the open position so that you'll get a very high idle for a while. Sometimes you've got to get the engine warm and shut it down to let heat soak into this valve without freezing cold air being pulled through it, before it'll loosen up and regulate air properly. If you have a working heat stove arrangement in the airbox, you don't usually have this problem.

Aside from that, it's about as bulletproof as any 30 year old fuel injection system can be!

Good heavens - this makes the function of an SU seem simple and logical. Thanks for the review Matt. I'll read it over a couple more times to see if I can retain any of it.

Jeezus Matt. Did you get anything done at work today?

And Craig, I've got a 240 Haynes manual in the garage. You're welcome to it. Might even have a couple of '81 specific green manuals kicking around. I loaned my green K-jet manual to some and never got it back. Or maybe I sold it...I forget...

That was about a half hour of typing, maybe 45 mins. Not too bad.

Oops - been out working again and missed this post. I just picked a new Haynes up at CanTire. I cleaned up the under hood and Greg and I (well mostly Greg) made a list of stuff the car needs. We had a good haul out at the PYP today. They just got in an early 70's ('76 - '77) 242 and it donated a bunch of parts to Greg's car and some seat belts to my 242 (these ones retract better). There were also a few other bits of trim, a headlight switch, one turn signal, under dash trim panels, goofy panel to cover the passenger side butt cheek, and a few other things from various other cars.

The GT seat mystery is solved - these are not Matt's seats as they don't have a metal pan. The drivers seat bottom is on the passenger side, not just the base as the passenger seat springs etc are essentially not there. I'll be looking for a good set of 240 seats to swap the needed parts to make the GT seats perfect again.

The OD is not working. It went once this morning, but is intermittant (I knew about this) - not sure where to start bird-dogging that one, but I'm thinking start with the fuse box, then check the switch, then the relay, then the solinoid/change fluid.

I have to get this done before any road trips - don't want to scare people in 4th on the highway.

Matt, thats a very good description of the bosch k-jet in a nutshell.

A couple tricks not listed at the bottom of Matt's post:
Drilling small holes in the casing of the fuel pump relay is one way to prolong relay life on a healthy car. Further, keeping the filter changed often and not running the tank down will keep you from having to change relays, intank pumps, or other major parts as a good foundation for making the K-jet work right no matter what everything else is doing.

Our warmup regulators or control pressure regulators (WUR and CPR, respectively (same thing)), usually go the other way. They usually clog to the warm position and the car is very difficult to get going on a cold morning. I don't know if that is a difference in your climate or fuel, but that is what seems to happen. Cali cars don't seem to eat CPRs much for whatever reason. One car I worked on had about 430K miles on it and the original CPR. I was impressed, but the car was driven a lot and kept up.

The idle air slide on the cam cover can be replaced by the "Constant Idle System" (Ironically abbreviated by volvo as "CIS," which is what many VW guys call k-jet). I like that system better, even though it means adding a small computer and wiring harness. The slides headsoak or stay frozen, and I just like the idle to be more stable to set timing and mix stuff. I'm not sure if you got these, but our 81-82 N/A K-jet cars usually have an electronic idle control valve where the slide is on the cam cover.

K-jet doesn't like to sit and doesn't like dirt or things to gum up and stick up. Abused, but mechanically maintaned complete rusty million mile piles of K-jet cars are usually the ones that run close to right around here. Lower mile cars that sit where the fuel filters etc aren't changed often are often the ones that develop sticky CPRs, bad check valves and so on.

I quite like turbo K-jet. I don't much like N/A k-jet now mostly out of laziness of not wanting to hook up my pressure gauge and shim the line pressure regulator on the fuel dist, adjust the mix etc with the whole K-jet mess jammed under the intake. It is possible to do those things with the intake in place, just not much fun. This dislike mostly comes from doing it on too many cars. Once you sort the K-jet step by step, it will run great and keep on running great as long as you drive and maintain the car regularly. I'd way rather have K-jet than a carb on my daily driver or a turbo car.

The bentley CIS chapter and some of the bosch manuals have very good k-jet descriptions. The bentley talks a lot about the fuel distributor and all the stuff that can break in it, which is cool to know about to learn how it actually works, but the fuel dist itself is a pretty uncommon failure (though does happen once in a blue moon).

The OD relay is behind the glovebox. Listen for the solenoid clicking with the key on and gearbox in 4th and light to come on. Fuse, relay, or wiring are most likely. Mechanical OD problems are usually less common.

Have fun with the brick volvo! I wouldn't bother with the haynes. I like the bentley and K-jet.org has some very helpful greenbook scans if you don't have green books handy.

Thanks James - The Haynes indicates that the OD relay is behind the vents, so I pulled the vents out looking for the relay and only found vent plumbing...what's with these modern cars with all their new fangled vents and plumbing? Glove box - that makes sense. I'll try that tonight. In the mean time the vents are now clean.

It is behind the vents....just kinda right below on the right side of the center vent.