Leaded or unleaded?

[shimon340]

putting this together then.....

What Renix units did the very first renix 340s use then in 1984/5? Presumably the 402?

The 402 with a C plug originally has a map suitable for 98 octane. Earthing pin 7 retards ignition 4 degrees which is a map suitable for 95 octane. According to info from volvodspec, this map is also suitable down to 91 octane.

If a 402 doesnt have a C plug, it doesnt have a means to access the map suitable for 95 (and lower) octane.

The 412's original map is the same as a 402 with pin 7 earthed ie unamended it is suitable for 95 octane. Earthing pins 6 or 7 (or both) gives a map retarded 6 degrees from the original (non earthed 402) which is suitable for the catalyser models. This would be a 2 deg retard from the 412's original map.

I'm having a look at a 1986 340 tomorrow and a 340 catalyser. I'll have a look which renix units they have. I recall the E reg was pinking on unleaded before pin 7 was earthed.

[shimon340]

hi

didnt get a chance to look at either of these cars over the weekend but at some point I'll have a look at a 1991 catalyser 340 and a 1986 B14. The 1986 one was pinking on 95 octane until the pin 7 of the Renix was earthed.

S

[volvodspec]

hi The 1986 one was pinking on 95 octane until the pin 7 of the Renix was earthed.

are you very much sure that the rest of that engine was ok?

before i put the turbo engine in my blue 340, that had a b14.4e with 402 unit and it allways ran on 95 unleaded with no problems or pinking and without a c-plug.

[shimon340]

hi

Both on this 86 B14 4E and a previous car of the same age both would pink at motorway speeds and higher revs. Not really in town.

I'm ill with a cold at the moment but at some future time I'll see what Renix units are on both the B14 4E with catalyser and the 1986 B14 4E.

Even if you're B14 4E with no C plug ran ok on unleaded 95 octane might still mean its running the more advanced map, you were just not inducing conditions to cause it to pink....

[shimon340]

http://www.volvoclub.org.uk/press/pdf/3 ... elease.pdf

model year 1987 runs on 95 or 98 octane from the factory. Presumably this is the 412 Renix.

Running a map which can run on 95 octane also allows one to run 98 octane (retarded map can also work on higher octane fuels).

Havent found a reference to 91 octane 340s yet.

[shimon340]

interesting archive document from Wouter

http://www.volvo300mania.com/forum-uk/v ... x&start=30

[volvodspec]

Both on this 86 B14 4E and a previous car of the same age both would pink at motorway speeds and higher revs. Not really in town.

that's strange, i've asked a bit and allmost everybody with a b14.4 fills it up with unleaded 95, and there are quite a few 85 and 86 among them too..

Even if you're B14 4E with no C plug ran ok on unleaded 95 octane might still mean its running the more advanced map, you were just not inducing conditions to cause it to pink....

then you don't yet know my driving style... my b14 engine engine will always hit 6000rpm with the cvt if engine oil is warm enough i drive it, let's say a bit "sporty"..

the b14's seem to like that way of driving; here's a pic of a 170.000km engine that came out of my red '89er and went into a 343 blue special:


old engine, 140.000km and "normal" drivestyle


my old engine was allready 7000km on that oil, the engine from that 343 just had it swapped 1000km before that..

it could be that the uk fuel is different, the b14.4 just should not pink on unleaded 95 without a c-plug i'm a bit confused why your car(s) do..

you probably won't find a reference for ron 91 too; i was just trying to say that if you need to fill it up with that garbage petrol; it would still run fine without pinking

[shimon340]

hi

thanks for the info.

I'm awaiting some info from Mac and also at some point seeing what Renix units are on some friends 340s (that's the 86 B14 4E and the catalyser one).

Dya have any Renix documentation you could upload?

Info so far suggests in this discussion suggests

1) first 340s with Renix had the 402. Early ones had no C plug
2) Then 402 with C plug. Earthing C plug gives 4 deg ratard for 95 octane.
3) model year '87 (after August '86) used the 412.
4) catalyser models use the 412 with pins 6 ans 7 earthed.

[Chris_C]

4) catalyser models use the 412 with pins 6 ans 7 earthed.

Mine still didn't have these pins earthed, or even a C plug Thats a June '91 B14

[shimon340]

hi

your info re the 402 being fine on 95 octane with no C plug doesnt make sense presuming the 402 with no C plug runs a more advanced map suitable for 98 octane.

Unless, the 402 with no C plug runs a map suitable for 95 octane (you also suggest is it ok down to 91 octane) and the 402 with a C plug runs a more advanced map with pin 7 not earthed and more retarded map (suitable for 95 octane) with pin 7 earthed.

412A runs a map suitable for 95 octane originally, and a retarded map for the catalyser models with pins 6 and 7 earthed.

Would expect a 402 with no C plug and 402 with plug to have different Renix part numbers.

NB volvo was offering a "unleaded conversion" to Renix and breaker 340s in the mid 90s. The kit consisted of a plug for plug c and an earth connection for pin 7. About 5 years ago I was told the kit was available and cost £21 by a local dealer. A technician at the same dealer confirmed earthing pin 7 on a 340 renix, lets the car run ok on 95 octane.

piece by piece getting this together! I've asked some more info from volvo300club.nl but I see you're also posting there!

[shimon340]

hi chris,

what renix model was in your 1991 catalyser?

[shimon340]

volvodspec, when you say "without a C plug" do you mean it was sealed with a rubber insert or indeed was there nothing in the place of the C plug?

Info from Mac,

in the UK all Renix units had a C plug, it was sealed with a rubber insert in 1984 (first 300 series to use Renix).

In '85' year models the socket was wired - pin 8 provided a signal for the dashboard "gear change indicator".

In '86' - '89'pin 7 was earthed to provide a 4deg. retard in the map. (you can earth this on '84' & '85' to run on 93 octane).

In '90' (two way catalyser) pins 7 & 8 were earthed to provide a 6deg. retard shift.

Archive document from Wouter shows model year 86 onwards uses a 412.(http://www.volvo300mania.com/forum-uk/v ... x&start=30 page 3)

84 onwards uses a 402.

So....402 originally has a map suitable for 95 or 98 octane? Earthing pin 7 gives a map for 93 octane

412 originally has a map for 95 octane? (4 deg retarded from 98 octane map of 402)
Earthing pins 7 and 8 gives a further 2 degree retard for the catalyser models....

Need to check the '86 and catalyser models still.....

[Chris_C]

A standard 412.

Surely you are making this a billion times harder than it is? A renix isn't that clever, surely not enough to have multiple maps, the rom isn't big enough for a start from what I've seen. Yes it may be able to do a blanket retard on the map, but nothing more.

What makes you think the renix table available in every technical Volvo publication ever is wrong?

[volvodspec]

that's with the rubber seal on c-plug;) and no wiring in engine loom present to earth the c-plug wires

A renix isn't that clever, surely not enough to have multiple maps, the rom isn't big enough for a start from what I've seen. Yes it may be able to do a blanket retard on the map, but nothing more.

yes thanks Chris, that's what i was trying to say! i know some basic technical words in english but if you want to say something and you need google translator for every dawm word you get tired and bored just thinking of it...

[shimon340]

hi Chris,

Just trying to clarify the Renix history and fill in some gaps in the data. Not saying the volvo info is wrong. I think you will find volvodspec is questioning Mac's info.

volvodspec being able to run a 402 on 95 octane with no C plug modification simply doesnt make sense unless the 402 from the factory is a map suitable for 95 octane. Info from Mac, earthing pin 7 gives a map suitable for 93 octane. Don't see how people can run 91 octane on such a map unless the map is compromised on 95 octane to allow down to 91 as well?

The 402 with pin 7 earthed, gives a map suitable for 95 octane. These cars (85-87) can therefore run on either a map good for 95 octane or good for 98 octane. No earth = map suitable for 98 octane. Seems a retro step compared to the apparant 402 base map being 95 octane and earthing pin 7 to give 93 octane map. Why later go back to a 98 octane map and a 95 octane map? Should also be part number change between the 1984 402 and the 85-87 402.

The 412 was introduced in 1987 model year. Seems to run map suitable for 95 octane without modification. Earthing pins 6 and 7 gives a further 2 degree retarded for catalyser models.

Your 1991 catalyser can run a 412 with no earthing of the C plug, map is just fine. However, emissions are better for this model on the 2 degree retarded map introduced later. Maybe your 1991 was an earlier catalyser model.