Hello All
Ive been looking at several 140s that have been advertised for sale. A number are the original FI (D-Jet I believe). Some have been converted to carbs either Weber or SUs. Obviously, the carbs are simpler and probably more reliable and parts seem to be more easily obtained.

Since the oldest Volvo FI system is now in the neighborhood of 40 yrs old, what is the parts availability like? Does the FI system approach the reliability of the carb options?

Thanks for your help on this.
Bob

I have driven my 71 B20E for 35 years. I accumulated spare components to plug in for problem solving. The only major component failures in 250,000 miles has been the MAP, TPS and the CLT sensors. I have have multilple failures due to the wire harness failure caused by worn out wire insulation and connectors.

Rather than replace the FI with carbs I converted my FI to a Megasquirt II system. I made a new wiring harness, used refurbished stock injectors and replaced the old ECU with a ECU that is programed from my laptop.

There was a huge learning curve, a lot more science was required than a carb conversion. So far reliability with MSII has improved over the D-jet mainly due to the new wiring and hardware.

The car is so much more fun to tinker with now. The D-jet and carb systems are not as adjustable as is the MS II system.

Regarding the previously mentioned fuel fire risk, I agree with replacing all old fuel lines with high pressure fuel hose and clamps to avoid fuel leaks and fires. Include having the hoses on the fuel injectors replaced as well at Cruzin Performance. Most all the old non refurbished injectors in cars are fire risks.

Nice new booties on an old D-jet wiring harness make diagnosis of broken connectors difficult because the connections and old wires are covered with the boot.
--
Antique Swedish Steel 71 142E color V#102

I have had my cts fail, new forty dollars, and a mapsensor fail, You can find deals if you look. I lucked out and got a modified map that was drilled out to make adjustable and it works great(have wb o2 in my car) my trip meter is and odometer dont work that often so not sure of mpg but runs great and starts all year round. I do want to do ms conversion at somepoint but that is just cause I want to do it.
jeric

There are 2 types of FI systems for the B20 cars -- d-jet and k-jet

The newest of these systems is almost 36 years old at this point. These things were probably designed to have a service life of about 15 years, and overengineered so the lucky ones are probably only now approaching the end of their service life. It wouldn't be reasonable to expect any of the original components to last another 10 years without replacement/refurbishment. If you want it to be reliable, you'll want to rebuild all the mechanical system (fuel injectors, fuel pump and MAP sensors and metering flaps (k-jet), and you'll want to double-check all the electrical components, wires, and connections. The connections get corroded and the insulation on the wires tends to get brittle.


D-Jet is an all electronic system that works by detecting manifold pressure. It was designed in a day where transistors cost hundreds of dollars each. As such it has all sorts of weird analog and mechanical thingies on it. It's an open loop system that just simply does what it does based on a very few inputs (vacuum and if the throttle was depressed recently and the temperature of the engine, and points in the distributor to decide which 2 injectors to fire) and it doesn't check the resulting exhaust to see if everything is behaving as it should. The good news is that it is very efficient and very reliable when everything is in tune and operating properly. The bad news is that the system was designed for a particular cam and displacement and if you change things too much, it simply won't deliver fuel correctly.


K-Jet was used in 1974 and is basically a big mechanical fuel metering thingy. Air moves past a flap, and the faster the air moves, the further the flap moves, and the more fuel gets delivered. All fuel injectors receive the same amount of fuel at the same time. It's a beautiful, elegant, and simple design that was in service in lots of european cars until the mid 80s at least. It is reliable and works extremely well as long as the fuel metering flap works properly.



If you want to set and forget, carbs are easy. Low fuel pressures are a lot less scary if things go bad, and you can tinker with them.

My money, though, is to get a d-jet car and convert it to megasquirt. The system is already very nearly modern in design and retrofitting MS just requires replacing the old, worn out systems that would need to be replaced anyhow.

chris

And it goes without saying:

Replace *all* your fuel hoses, and replace them with the really expensive fuel injection rated fuel hoses with the proper pressure rating, not just "fuel" hose.

And make sure your hose clamps are the proper types. None of this stuff matters with carbs, but if you use the wrong hoses or clamps on FI, you'll burst a hose and your car will empty the gas tank onto the motor, and you'll be sad (at best).

At forty years of age no fuel system is reliable, or in perfect condition. Given the strange complexities of the D-jet system it's a system for purists only at this point.
I began working on D-jet on VW, Mercedes and Volvo in the early 80's. Even then they were giving trouble. Ten years after that, and wiring faults, locked-up fuel pumps, blown pressure regulators, worn out trigger points, leaking injector hoses, worn throttle switches, AAV's that wouldn't slow down....you name it. I've also seen lots of burned up 140's and 160's from fuel fires....fortunately never to one of my customers - but close a few times....
So as the D-jet stuff is really expensive, and throwing new parts at a collection of used bits that aren't truly acting as they should.....one wonders.
Carbs are the answer. Not better in and of themselves, but the answer.

Given the strange complexities of the D-jet system it's a system for purists only at this point.

Complexities? If you don't understand D-Jet, you probably couldn't understand the "strange complexities" of a SU carb either...


--
Three 164's, Two 144's, One 142 & a partridge in a pear tree.

I think Rhys has really hit it on the head here. You kind of need to be either an D-jet aficionado, or trying to have an all original concours car. It's a weird specialty, but if you are fascinated by early production FI systems the D jet is for you. Of course if you do that some might call you a geek, but not me, I have my own specialized interests, and I 'm not a geek.....am I ?!?!?
--
Patrick ('68 220, '83 245).

I'm a SU guy. would never buy a FI volvo. If someone gave me one I would run it untill I had a problem and then swap in SUs. They are old cars, it's nice not to have no start problems, and SUs will not give you no start (at least not anything that can't be sorted immediately with what you have).
--
Patrick ('68 220, '83 245).

Rock solid when it works.
Start with a homemade pressure gauge on the cold start line.
Tire pressure gauge + 1/4" x 1/4" female NPT + 1/4" NPT male x 5/16" hose barb fittings.
--
71-145-S

I'm approaching 191,000 miles on my 71 d-jet,(driven daily) and yes it has been a learning curve getting to know its workings. Ive got it dialed in very nice these days, this car would not be the same without it. This is how it came from Sweden. 2 doors, fuel injection, overdrive, 71 gearing. They knew what they were doing. Now if I had some 140 that was missing alot of original parts I'd go for carbs, I have a B20 sitting in my garage that's waiting.......The best of both worlds.

I guess I'll be the detractor here - I converted from d-jet to carbs 4 or 5 months ago, never looked back. I had a hell of a time tuning d-jet, and went through multiples of new components before I found working stuff. I also never got better than 15mpg on d-jet. With carbs I'm getting better than 20mpg. I find the carbs much easier to tune, and I think the performance is comparable if not better to FI.

Ben,

I'll be embarking on the same project this winter. At present, I'm collecting the bits and pieces I figure I'll be needing and sort of planning the sequence of implementation - I'll need to replace the hard brake lines as well.

Question: How did you handle the fuel supply? Same feed line without the electric pump but using the same connection and pickup in the fuel tank? Kept the electric pump but with a pressure regulator? I'll be using a mechanical pump.

I'd appreciate any and all pointers.

Bob S.

--
‘62 PV544 (B20, M41), '71 142E, '93 240 Classic Wagon.

Hi Bob,

I definitely removed the electric pump and went mechanical. I would advise replacing all the soft lines from the tank to the hard lines, mine were pretty brittle. Didn't touch anything in the tank itself. As long as you use the right mechanical pump for your carbs, and spacer, you won't need a pressure regulator.

I just plugged the return line in the engine bay. When I have time I'll be plugging it closer to the tank.

Hi guys,

I've owned several B20E 140 D Jetronic cars and a couple 164E cars and the biggest problem I had with parts was the pressure sensor that sits on the passenger side fender housing. The diaphragm would break and there were no parts available. At the IPD garage sale last summer I saw several of the sellers with them, one had a pile of them.

Hope this helps.
Charles

Hi Charles,

The MPS is not the culprit in my case. I have a known-good spare that I have swapped in to no effect. I suspect that my problem, aside from the fact that at the moment I'm unable to get the idle down to a reasonable level, is in the deteriorated wiring. In dry summer weather the car runs fine, but in winter, especially when it is not freezing but just cold and moist, the running becomes erratic, no matter how much I polish all the contacts and connectors and put anti-corrosive paste on them. And that won't do because this is my winter beater, or, at least, was till it became unreliable.

Bob S.

I know you mentioned the oldest Volvo FI system, which would be D-Jet; but note that there are K-Jet 140s, as well (1974 only). I have one and have found that it's about 50/50 on parts availability, with many things popping up here and elsewhere online fairly regularly and some major parts still available new, but with crazy prices.

As far as reliability, I'll let you know if I ever get mine running!

Once you get it set up right with good components and new hoses they are pretty reliable.
Some of the parts are hard to come by and expensive but they seem to last pretty well.
I have (25 years ago) converted cars from D-jet to carbs but would not do it now unless there
was no other alternative. I have 2 cars with D-jet and plan to keep them that way.
I DO have a considerable culch heap of parts.

"I DO have a considerable culch heap of parts."
Do you huh.....?
Do you have a working Cold Start Injector that is for sure not stuck open?
Do you have an Auxillary Air Valve that is not stuck open?

I know the cold injector is available but $150...please...
AAV is pure unobtainium except that Automotive Tradition rebuilds them for like $400...

I've found that a couple tromps on the gas pedal does as much as the cold start injector -
as far as I know mine doesn't work (wiring problem) but if you'll e-mail me your mailing
address I'll send you a cold start injector.
send it to gdowns [at] cableone [dot] net [nothing follows]

Dave Farrington refurbed an AAV for me and it works great. I sent him a link to your post.
BTW I drove the Yellow Peril through a couple winters without either cold start or AAV.
Had to keep my foot on the gas for the first few minutes but as soon as it was warm it was OK.
You can also put an electric AAV from a B21 on it. Needs to be wired and plumbed.
(wired into the ignition circuit - I think I used the wiper circuit.)

Personally I've seen every part of the D-jet system advertised somewhere at some time. Sometimes way overpriced, sometimes great deals. Get a few spares when they come up and don't worry about it. Totally not worth converting to carbs in my opinion. Once it's all sorted D-jet is totally reliable.

Just like anything else, when the parts get old, either by age or by miles, you've got to replace them. The D-jet system is a 40+ year old design but it works the way it was designed to if you keep it up. Back then, Volvo recommended replacing all the sensors every 100000 miles. The parts are out there. Is it as good as the new fuel injection systems? No. It's design is 40 years old. My '73 get 25 mpg on the highway and it's not in the best of tune. It's never failed me.