P1800 ES 1972 FOR SALE £1800 ono

[capt jack]

This ES should almost certainly be a Bosch D-Jet fuel injected car, unless something fairly radical has been done to it.

Getting a D-Jet car to run well is a bit of a challenge it true. The system is one of the very first electronic fuel injection systems to be used in mass-production cars.

Looking at the shot of the engine bay, this car has obviously been modified at least to some extent, with the addition of what looks to be some sort of vacuum-dependent variable fuel pressure regulator.

When new, this car would have had the standard Bosch reg, set to 2bar. This one has a tube running from what looks like a non-standard pressure regulator to the inlet manifold, which I would guess means that a previous owner has attempted to introduce a regulator that would vary the regulated fuel pressure according to inlet vacuum. This D-Jet system was never meant to run this way, but at a fixed 2bar pressure, and this could indeed be a part of the 'engine management system' problem referred to by the vendor.

If the engine isn't running very well - and I guess that can be inferred from the posting, then the reasons are likely to be a combination of the following:

As the car isn't in regular use the fuel tank will almost certainly be rusted on the inside, and the petrol stale. The mesh filter on the bottom of the pick-up pipe will be clogged, as will the fuel filter, petrol pump and fuel lines. That home-made pressure regulator may well be affecting things too. This will all cause a drop in delivered fuel pressure, which will give running problems.

Electrically, the throttle switch will almost certainly be dirty, as will the fuel injection trigger points in the base of the distributor. The injectors are probably less than efficient just now, and the two coolant sensors and the pressure sensor would need careful investigation.

The inlet manifold will need a bit of attention too, to make sure that there are no air leaks, and the brake servo non-return valve may need replacing.

The earth straps are probably dodgy, as will be the electrical connections throughout the fuel injection loom

The other probable trouble-maker will be the auxiliary air inlet valve - chances are it's stuck!

All this of course is assuming the ECU is working OK.

For the prospective purchaser and eventual new owner, the choice will be either to get stuck in to the vagaries of the D-Jet system, or to fit the twin carbs. But be warned, D-Jet expertise and spare parts are both in short supply, and your local friendly garage will almost certainly be clueless about the 1970s technology at the heart of the Bosch D-Jet system.

The D-Jet system certainly can be made to run OK, but it is a little tricky, and it does rely on everything working exactly right.

Cheers

Jack

[dorianwilliams]

Jack, many thanks for the possible explanation as I don't have a clue! Might be best to convert to twin carbs or find someone who knows what they're doing. Dorian

[capt jack]

Well I only learnt all this the hard way, by getting a non-running D-Jet ES back into running order! Mind you it took me over two years!

I no longer have the car, but I do still have all sorts of references and 'how-to' guides from different manuals, so if anyone wants any help with this I'd be happy to oblige.

The same fuel injection system was used quite extensively by several manufacturers - MB, Porsche, VW and Renault - and as well as my Volvo stuff, I've got information from these other sources too.

Cheers

Jack

[biggbn]

i have my car for sale at the minute, if it sells i will be very interested in this volvo, gbn

[biggbn]

if i bought this car, how much hassle would it be to junk the system and fit twin/single carbs..not too bothered about oomph, just love the 1800es shape/practicaltiy

[johnjp]

I see the car is a `72, is it road tax free?
Is it at all driveable?
I presume it is as it could not pass an M.o.T if not!
I am very interested but live near Brighton, so quite a drive!
My first FI 244 was problematical, probably due to a tank leak as, though I am no mechanic, I believe pressurization is crucial to efficient running!

[dorianwilliams]

I am told it is tax free as manufactured in 1972 although registered in 1973. I shall get it taxed. I can't really advise when it comes to mechanical work. It does drive but idles erratically. Beyond that I've not investigated. I was advised to collect by trailer which I did so this would be more sensible until you know what needs doing. I also have a non running Saab so this is yet another distraction I could do without!

[johnjp]

The `log book` should indicate the date it was first registered, I guess if it is Jan/Feb `73 there is a good chance it was built in `72.
Can you confirm please?

[capt jack]

Yes, a swap to twin carbs is perfectly possible. Obviously the originality is then lost, and you'll have all the familiar issues that go with 40-year-old carb installations, but many would argue that that's a better option than all the issues that go with 40-year-old Bosch D-Jet systems!

The FI system as fitted to a later 244 is a very different animal. In the D-Jet everything is crucial to efficient running, and you must remember that the system only covers the fuelling, the ignition is all completely conventional - points, condensor, coil, etc etc etc.

I do stress that the Bosch D-Jet system is nothing like more recent fuel injection offerings. You will find it very difficult to get any help from any garage, also, some of the components are getting harder if not impossible to find.

That isn't to say don't do it, but if you're going to take on a D-Jet car you need to be prepared to be getting your hands dirty!

As for the build date, at the time Volvo very helpfully date-stamped very many components. If you look at the car's wheels - assuming they're original - and items like the various relays, you should find many of them with date stamps. If these all show 1972 then you're laughing all the way to your local DVLA office!

Cheers

Jack

[dorianwilliams]

Yes - 12 months' free tax now on.