[Diy_efi] info request

Wed Aug 16 21:04:09 UTC 2006

A Volvo P1800E (like all other fuel injected Volvos of that era with 
B20E, B20F, B30E or B30F engines) has Bosch D-jetronic injection from 
about 1969 to 1973. From 1974 on, all 4-cylinder models used the 
mechanical K-jetronic system instead.
The 6-cylinder Volvo 164E however still used D-jetronic until 1975, when 
that model was superseded by the 264, with a completely different engine 
and K-jetronic.

The D-jetronic was the world's first mass produced EFI system. It was 
initially developed by Bendix, but Bendix saw no future for it and sold 
the whole concept to Bosch in the mid-60's. Bosch then in a few years 
developed it to a field useable system, it was first used on the VW 
1600E '68, and by 1969 it was implemented by a lot of european car 
manufacturers.

Of course, that early system has some weaknesses.

The temperature sensors (for coolant and air temperature) often get 
open-circuit.

Early throttle position switches are not well sealed and must often be 
cleaned to work well.

The pressure sensor (a very vital component) contains a metal membrane 
that may crack. Also, it is sensitive to dirt coming by the vacuum line.
It is a odd design, a transformer where a part of the core is moved 
according to the intake manifold vacuum. That transformer is connected 
in the feedback path of a monostable flip-flop in the ECU, which 
determines the injector opening time.

ECUs made before 1972 has big problems with all feedthroughs between the 
sides of the double-side PCBs, they are implemented as component pins 
soldered on both sides (no plated-through holes). Due to thermal 
fatigue, the soldering will soon crack on either side of all such 
feedthroughs. From 1972 on, those were replaced by "C-jumpers", i.e. a 
short jumper where one leg is soldered on the primary side and the other 
on the secondary side.

The injector drive transistors (germanium parts, ASZ18 or similar) are 
said to fail often in hot climates, although I never have seen a such 
fault here in Sweden. Probably, this is a bigger problem on ECUs for 6- 
or 8-cylinder engines where the transistors are more heavily loaded and 
more heat from the injector ballast resistors is generated within the ECU.

A non-electrical problem is that the short pieces of fuel hose crimped 
to each injector is of low quality and soon gets leaky. This has caused 
many fires. On injectors manufactured before about 1973, the  crimp can 
be filed away, the hose replaced and secured by a normal hose clamp. On 
newer injectors, a special hose replacement set was once upon a time 
available from Bosch.

Best regards

Torbj?rn Forsman

Dmitri Pronin wrote:
> Don't they have Bosch "mechincal" FI?
> ----- Original Message ----- From: "Rick McLeod" <dunvegan at sbcglobal.net>
> To: <diy_efi at diy-efi.org>
> Sent: Tuesday, August 15, 2006 7:29 PM
> Subject: Re: [Diy_efi] info request
> 
> 
>> Also, the references I find show the 1800E to be EFI as of approx 1969 
>> or so, maybe 1970, so suspect this one (1971) to be EFI
>>
>>
>>
>> ----- Original Message ----
>> From: Rick McLeod <dunvegan at sbcglobal.net>
>> To: diy_efi at diy-efi.org
>> Sent: Tuesday, August 15, 2006 10:00:23 AM
>> Subject: Re: [Diy_efi] info request
>>
>>
>> So, if not, I still need to know some info, as I'd like to convert to 
>> EFI if it is not the greatest system, if it's a good mechanical then I 
>> won't bother, but I don't know what it is at all and the car is some 
>> 1000 miles from me, I can't just go pop the bonnet!
>>
>>
>> ----- Original Message ----
>> From: Dmitri Pronin <dmitri_pronin at mail.ru>
>> To: Rick McLeod <dunvegan at sbcglobal.net>; diy_efi at diy-efi.org
>> Sent: Tuesday, August 15, 2006 9:01:22 AM
>> Subject: Re: [Diy_efi] info request
>>
>>
>> Wow!!!
>>
>> That one is one nice car! However, its injection system is not in fact an
>> EFI.
>>
>> Dmitri.
>>
>> ----- Original Message ----- From: "Rick McLeod" <dunvegan at sbcglobal.net>
>> To: "diyefi" <diy_efi at diy-efi.org>
>> Sent: Tuesday, August 15, 2006 4:55 PM
>> Subject: [Diy_efi] info request
>>
>>
>>> Does anyone know anything about a Volvo 1971 1800E w/ 2.0Litre FuelInj,
>>> like what system is used for control?
>>>
>>> I am looking at one but currently don't know much about it other than I
>>> know the owner very well and own 3 recent 90's 850's currently.
>>>
>>> Any info appreciated, links to tech, etc.
>>> _______________________________________________
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>>>
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> 
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