Electronic Ignition


From: Martin Bristow
Date: Fri, 13 Nov 1998 17:37:04 -0000
Subject: [imps] Electronic Ignition

FAO Nick

I've got a dizzy and module from a 930.
What car does the Bosch module come from?
What's wrong with the Crysler module?

Any advice gratefully received!

Thanks

Martin Bristow


From: Gary and Carol Henderson
Date: Tue, 17 Nov 1998 00:20:43 +-1300
Subject: [imps] Re: Electronic Ignition

Hi Martin

The Chrysler module coped with up to 8 cylinders at reasonable revs, so on a four it should go OK!

People sometimes stuff them by getting the connections to the external ballast-resistor block wrong. One half is a 1.2 ohm for the coil, the other higher (I forget the figure - can find if anybody needs it) is the collector -load for the driver transistor. The driver doesn't like pumping 10 A ...

Cheers
GaryH


From: Ewins, Paul
Date: Tue, 17 Nov 1998 08:16:00 +1100
Subject: [imps] Electronic Ignition

> you may be lucky to find a Chrysler Sunbeam 930 Engine with a BOSCH distributor

To find something like that in Australia would be very lucky indeed. Any sort of Imp bits are rare so I tend to look for solutions that don't involve chasing parts from mail-order suppliers.

> Mine always fire up instantly on my Clan

What sort of fuel pump are you using? I still have the mechanical one fitted but was considering swapping over to an electric one.

Paul


From: Nickcleak@aol.com
Date: Mon, 16 Nov 1998 16:54:26 EST
Subject: [imps] Re: Electronic Ignition

> One half is a 1.2 ohm for the coil, the other
> higher is the collector-load for the driver transistor.

The Bosch ones cope with 25amp + coils ... ( 0.5 Ohm primary windings ) despite the chrysler ones being sealed ,water still played a part in their demise , that awfull connector block for example !

nick


From: Nickcleak@aol.com
Date: Mon, 16 Nov 1998 16:54:24 EST
Subject: [imps] Re: Electronic Ignition

> What car does the Bosch module come from?
> What's wrong with the Crysler module?

Well , there were quite a few cars in thge 70's and 80's with Bosch coil switching modules which will interface directly with the 930 distributor . The 930 distributor actually generates an electrical voltage spike and sends it to the coil switching module .

The car i had in mind was Volvo 244 injection .. 1975 to 1981

There are many other units suitable i dare say ..

Chrysler units were unreliable ! Ok , one may fail once or twice in your ownwnership and may not bother you , but i saw a lot changed ! Bosch units don't go wrong as a rule ..( fingers crossed ! ) certainly not the older ones ..

Nick ...


From: Nickcleak@aol.com
Date: Mon, 16 Nov 1998 18:00:35 EST
Subject: [imps] Re: Electronic Ignition

> What sort of fuel pump are you using?

An electric one , but i don't think much fuel would evaporate overnight as the Weber float chambers are quite large ..
The standard pump is said to be ok for 'normal' use , but not racing.. Nick ..


From: Gary Henderson
Date: Tue, 17 Nov 1998 12:38:33 +1300
Subject: [imps] Re: Electronic Ignition

Hi Nick

What I meant here, is the 'little' driver transistor, the one which feeds the base of the 'big' TO-3 pack switching transistor. The biggie is OK for 10 A at least, probably 15 A, but the driver gets tired at (guess) 3-4 A.

Obviously, you can buy bigger brighter devices nowadays.>

>despite the chrysler ones being sealed, water still played a part in their demise
Sealing, potting etc serve little useful purpose, other than to hinder people who could otherwise repair things! Unless extremely well done, these measures are more likely to be unhelpful to reliability. And the only way to keep water from getting into mischief is to arrange for it to fall out faster than it can creep in. (I've had to solve water vs electrics problems in steam-irons and juicers etc. as well as house and cars.)

Cheers
GaryH




From: Nickcleak@aol.com
Date: Tue, 17 Nov 1998 14:40:20 EST
Subject: [imps] Re: Electronic Ignition

> Obviously, you can buy bigger brighter devices nowadays.

yes , but The Bosch was the thing in the 70's too ...
Nick ..


Date: Tue, 17 Nov 1998 18:21:11 +1000
From: Darcy Maddock
Subject: [imps] Re: Electronic Ignition

Hi Paul,
I acquired an electric unit for a Mercedes Fuel Injected car. It is tubular and is designed to lay on its side and is inline. It came with a rubber insulated bracket.
I made up a thick alloy plate to fit the hole where the mech pump was and the bracket fits one of the original bolts. From there it goes into a pressure reduction device which I have set at 2.5lbs for road use and I up it to 3.5lbs for Track use.
It is powered from a spare lug on the solenoid via a hidden cut-off switch. Unfortunately it takes about 4 miles before it runs out of fuel so I am looking for something else to disconnect. The pump itself is only heard when the ignition switches on, you cannot hear it when the car is running. Much better than the Lucas units.
Darcy Maddock


From: CKirkw00d@aol.com
Date: Wed, 18 Nov 1998 08:24:47 EST
Subject: [imps] Re: Electronic Ignition

Paul,
I've just finished it on the computer, literature and diagrams scanned in. The size using word 7 is 1.48Mb. Too big to e-mail at the moment. I'm trying to get help to shrink it. If the worst comes to the worst then I'll post you a copy.
Colin K.



From: TMo5018257@aol.com
Date: Tue, 24 Nov 1998 13:33:37 EST
Subject: [imps] Dizzy Query

Hello all,

I've read an article in "Classics" magazine about Imp engines (very good article) - however......

They say in this article that the early type distributor (25D4) is 'known for poor balance of the bob-weights upsetting the ignition timing. The later type models have the more reliable Lucas 45D4 distributor which can be retro fitted to earlier or tuned engines.'

This goes against everything that I was told about Imp dizzies. On L4 engines, I was told that fitting a Sport dizzy increases power output and reliability, as the base-plate on the late dizzy is not attached as securely and that the L4 was detuned mainly by a poor advance curve, so that the advantages of the sport cam were not utilised. Certainly on L4s I've run in the past, fitting the earlier Sport dizzy improved performance.....

I know that the Bosch dizzy & electronic ignition is more efficient, but I am still running a 25D4 on the Husky, and would like to hear your thoughts.....

Cheers,
Tim


From: Nickcleak@aol.com
Date: Tue, 24 Nov 1998 16:07:39 EST
Subject: [imps] Re: Dizzy Query

Me too ! the later ones seem to have been cheapened and the base plate is secured by a self tapping screw expanding a slit in the baseplate to jam it into the body .
If i designed something like that i'd be sacked !

Nick ..