1980 2ltr CU electronic ignition problem. Help please

Post by **horizontal kipper** » 23 Sep 2007, 14:15

I had the center of no1 spark plug leave the plug still attached to the HT lead happily sparking away near the fuel line!! on the M5. New plug in sorted, came to use the van today after standing 2 weeks engine turns over no probs but no start, fuel ok but no spark at any plugs. did a resistence check on coil, OK. Bypassed ISU a while back so am i correct in thinking the amplifier unit or dizzy are shot is there a way of testing these? have replaced the rotor and cap and Ht leads.

Thanks

Paul & Gill

Post by **HarryMann** » 23 Sep 2007, 14:43

Sounds like running with an open circuit might have damaged one of the units... but keep checking, might be another reason. Best would be to substitute the Hall amplifier box for a known good one. I'd also change all plugs for new ones if haven't already

Post by **toomanytoys** » 23 Sep 2007, 14:46

Dont be tempted to start probing the dizzy with a volt meter... no good..
swap out the amplifier (next to the ISU).. and check all connections.. check you have 12v at the coil with ign on too...

Post by **VWCamperfan** » 23 Sep 2007, 17:46

I had the hall sensor in the dizzy pack up a few weeks ago. Went to local breakers and got another distributor. Stripped this one down as mine was in better nick and took out the plate with hall sensor on it and swapped over. Running fine now. Can give up the ghost in a matter of 100 yards of coughing and spluttering, usually a way to tell its that that has gone but can just stop working between one run and the next.
A way to tell is to get someone to turn over the engine and open and close the pugs a few times that run to the idle stabiliser unit. If it fires for a second, its the hall sensor that packed up.

Post by **horizontal kipper** » 24 Sep 2007, 09:50

Thanks, looks like the hall amplifier has had it.
If i was to scrap using electronic ignition & move over to points would the dizzy from a late bay CJ motor work ok if i blank off the vacume retard outlet off the carb's manifold's balance pipe, keeping the vacume advance? would it need to be timed at 7.5 BTDC rather than the 5 ATDC?

The dizzy part number i have is BOSCH 0231 168 005

VW part number is 021 905 205P

Post by **richnewton** » 24 Sep 2007, 10:24

I'm not 100% but I think mr baxter sells the hall units? would be easier just to replace this and stick with standard set up.
[url]http://www.brickwerks.co.uk/

Post by **The_blue** » 24 Sep 2007, 10:31

horizontal kipper wrote:Thanks, looks like the hall amplifier has had it.
If i was to scrap using electronic ignition & move over to points would the dizzy from a late bay CJ motor work ok if i blank off the vacume retard outlet off the carb's manifold's balance pipe, keeping the vacume advance? would it need to be timed at 7.5 BTDC rather than the 5 ATDC?

The dizzy part number i have is BOSCH 0231 168 005

VW part number is 021 905 205P

Don't do it!

Mine came like that and was crap

ended up getting a full syste from a scrapper.

Post by **HarryMann** » 24 Sep 2007, 10:45

Don't do it!

Was about to post exactly that too...

So i will just to emphasise, its the non-std ones that usually get in a right mess, or so it seems from Tech Advice...

was it running OK before? Yes!

Why even consider changing it, just repair it!

Post by **toomanytoys** » 24 Sep 2007, 10:56

Just change the hall sensor.. going back to points is a big backwards and you have to change the coil too..

while its apart check the vac unit is working correctly too..

Post by **horizontal kipper** » 24 Sep 2007, 11:18

The reason i asked the above is because i broke down a 72 bay around 6yrs ago that had a 2ltr CU fitted with a dizzy from a CJ from what i remember it went realy well. i still have the motor. I dont mind setting points but if you all say to keep the standard set up then ok.

Thanks

Paul

Post by **toomanytoys** » 24 Sep 2007, 13:43

Well you could always fit it and keep yerself goin and see how it goes.. is a CJ a 2L too?...

Post by **Rozzo** » 24 Sep 2007, 17:10

go fer the points m8,,, much easier technology to understand imho. mines on points and if they open and close it goes bang, end of.

Post by **mrhutch** » 24 Sep 2007, 21:50

I have a spare dizzy known-good if you need it fella

from a running CU engine

Post by **horizontal kipper** » 25 Sep 2007, 10:10

toomanytoys wrote:Well you could always fit it and keep yerself goin and see how it goes.. is a CJ a 2L too?...

Yes the last 2ltr CJ used in the last bays also had hydrualic liftters. early CJ motors i think were 1800cc with solid lifters.

MR HUTCH, sent you a pm.