340 1.4 rough ans slow idling

[Two340'sman]

Originally Posted by Clan

Just about the only thing that can cause problems with a B14 is the RENIX ignition computer after 3 years , Always carry a spare and try and locate one whilst they are still around second hand ... there are different part numbers/maps in them for the various engines and model years but ANY One will get you home in an emergency ..

Thanks, I was wondering about this. I do have a spare from a 1.7 GLE. I will dig this out.

[Clan]

Originally Posted by Two340'sman

Thanks, I was wondering about this. I do have a spare from a 1.7 GLE. I will dig this out.

no harm it trying it driving gently around as the ignition timing will not be optimised . I meant 30 years above not 3 !

[Laird Scooby]

Originally Posted by Clan

no harm it trying it driving gently around as the ignition timing will not be optimised . I meant 30 years above not 3 !

I thin you had it right the first time! I've known a few Renix failures after 3-5 years, they didn't fare much better in the 400 series Volvos or the Jeep Cherokee (and associated models) and was quickly dropped by Chrysler-Jeep as they were at the time.

Also in the 7/9xx models, the Renix was fitted, if memory serves we didn't get it in the UK but they did stateside and gained a bad reputation for failing quickly hence Volvo reverting to the Bosch system.

[Two340'sman]

I have (amazingly) found the Renix unit that I removed from a working 1.7 340 GLE. I ran the car for about 10 years. It was very dirty, cleaned it up a bit.

Strangely, it's marked with 360. Couple of pics.

Removed from 1.7 by A60man, on Flickr

Removed from 1.7- by A60man, on Flickr

[Two340'sman]

This is the one on the 1.4 340, does anyone know what the small capacitor with the red wire is for? The Renix on the 1.7 did not have this fitted (I think).

on 1.4 by A60man, on Flickr

[Laird Scooby]

Some people (especially those working in breakers yards) didn't ever know the difference between a 340 and a 360. I don't recall the 360 ever having the Renix system on it, with the oddly named B19 (1986cc) engine, it ran Hall-Effect triggered Bosch ignition with the dizzy mounted on the side of the block and its own vacuum capsule on the dizzy body. Can't remember what the later (86/87 on) B200 powered 360 had, if memory serves the dizzy was still block mounted as there wasn't room between the back of the cylinder head and bulkhead for the cam mounted dizzy so again, it would have been Hall-Effect.

Don't worry about the small capacitor, it's there to reduce interference from the coil.

[Two340'sman]

Originally Posted by Laird Scooby

Some people (especially those working in breakers yards) didn't ever know the difference between a 340 and a 360. I don't recall the 360 ever having the Renix system on it, with the oddly named B19 (1986cc) engine, it ran Hall-Effect triggered Bosch ignition with the dizzy mounted on the side of the block and its own vacuum capsule on the dizzy body. Can't remember what the later (86/87 on) B200 powered 360 had, if memory serves the dizzy was still block mounted as there wasn't room between the back of the cylinder head and bulkhead for the cam mounted dizzy so again, it would have been Hall-Effect.

Don't worry about the small capacitor, it's there to reduce interference from the coil.

Thank you, this is what a reckoned happened, spare part bought from breakers yard and that they got the description wrong.

I wonder if that suppression capacitor has failed causing a problem. Should I disconnect it to see if that makes any difference, before changing the whole Renix unit?

[Laird Scooby]

Originally Posted by Two340'sman

Thank you, this is what a reckoned happened, spare part bought from breakers yard and that they got the description wrong.

I wonder if that suppression capacitor has failed causing a problem. Should I disconnect it to see if that makes any difference, before changing the whole Renix unit?

That would be a nice cheap fix if so! It's rare but can happen so give it a go, it also fits with the temperature related theory i have.

[Clan]

Originally Posted by Two340'sman

This is the one on the 1.4 340, does anyone know what the small capacitor with the red wire is for? The Renix on the 1.7 did not have this fitted (I think).

on 1.4 by A60man, on Flickr

Radio interference suppression :-)

[Two340'sman]

Originally Posted by Laird Scooby

That would be a nice cheap fix if so! It's rare but can happen so give it a go, it also fits with the temperature related theory i have.

Thank you.

I removed the capacitor, no difference.

Next I fitted the Renix unit from the 1.7 340, started the engine and I thought we had cracked it. Engine ran and ticked over nicely, then after a few min same old problem, rough and slow idle.

Looked at the distributor cap (was new about 3 years ago) and it didn't look that good inside, so fitted a new one, again thought we had solved it as initially good tickover, then back to slow and rough tickover. When it changes from good tickover to rough, the exhaust issues a little black smoke that persists until revs are raised.

I'm thinking the temp relation theory is quite likely.

Perhaps tomorrow I'll look for my compression gauge.