[Diy_efi] info request

Tue Aug 22 02:19:22 UTC 2006

your post implies some in-depth knowledge of D jet.
Do you have any info about tuning the full load (analog) "tables". We can 
change the pressure for a linear/across the rpm range change (like changing 
a main jet). How can one change the curve of the "table" (like changing an 
air correction jet). I assume it involves changing some resistance and/or 
capacitance values in the box. Phil Hunt. Phil's Foreign Car Service (former 
Volvo's From Hell driver-now very interested non participant)
----- Original Message ----- 
From: "Torbj?rn Forsman" <torbjorn.forsman at gengas.nu>
To: <diy_efi at diy-efi.org>
Sent: Wednesday, August 16, 2006 5:04 PM
Subject: Re: [Diy_efi] info request


>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 that model was superseded by the 264, with a completely different engine 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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>
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