Leaded or unleaded?

[shimon340]

The ANSWER courtesy of Mac!!

"1984 (begins with A reg.not B reg), 402 unit, mapped for 98 octane - suitable for unleaded but likely to pink on 95 octane. can be retarded 4deg. by earthing 'C' pin 7. (socket 'C' sealed from factory).

I have never seen a 300 series Renix without the 'C' socket - doesn't mean it doesn't exist though.

1985, 402 unit, socket 'C' pin 8 triggers gear change light on dash., mapped for 98 octane, can be retarded 4 deg.by earthing 'C; pin 7. Volvo brings out wiring kit to convert, and begins to fit kit in production.

1986, 402 unit, same map, socket 'C' pin 7 earthed at factory. Gear change light discontinued.

1987 on, 412 unit, pin 7 earthed at factory for car to run on 95 octane unleaded. I do not know how different the actual map is from a 402 but pin 7 still gives retard 4deg.

Catalyser cars I believe also have a further 2deg. retard by earthing pin 6 as well.

Earthing pin 7 was Volvo conversion for LOWER OCTANE fuel - whether leaded or unleaded.

[shimon340]

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

which means you're running a 402 with a map suitable for 98 octane. You didnt get pinking on 95 octane for some reason though...should of....

[shimon340]

In the end then it is quite simple.

a 402 or a 412 will unamended run a map suitable for 98 octane.

Earthing pin 7 will run a map suitable for 95 octane.

Earthing pins 6 and 7 gives a further 2 deg retarded map for the catalyser models.

Indeed, I appreciate is might not have a complete map of each rather it just adds an amendment map to the original to get the modification. That's the way the 850 knock control works, maybe the 400 series Renix too (see above for SAE paper from Renix research team about knock control - I think I posted the link). In the 850 at least, when knock is detected an adjustment map or jut simply another map is added to the original giving overall a more retarded map. Makes sense for Renix to work this way too.

Anyway, nice chatting with you all.

S

[shimon340]

Interesting, someone is now selling a genuine lead based additive for making genuine leaded fuel

http://tetraboost.com/

I guess the ban on leaded fuel is only for large volumes?

The Renix situation seems to have gotten a lot more complex now given some more info from volvo300club forums.....

[volvodspec]

it has indeed; most surprising but expected post from that topic quoted:

Antiekeradio
It seems that we are approaching the point where everybody knows they know nothing.. which is a good starting point for gaining new knowledge

that says it all i think.

[shimon340]

hi

yeah.. wasnt sure if that was a compliment or not.....

Seems the moderators on volvo30oclub.nl might want the discussion to move back here to the English forum.

I'll try to upload some info I've got this week as Wouter has also posted some in re CVT cars. The green book I have also details different ignition timing for CVT cars verses manuals. Or, at least it seems.

Just to confirm, volvodspec, you were running a B14 4E with a 402 Renix on a CVT car on 95 octane unleaded with no issues of pinking? No C plug earthing at all?

S

[volvodspec]

yeah.. wasnt sure if that was a compliment or not.....

it was actually; it is very rare that even Wouter gets his hands around a question that he can't solve out of his head or from documentation, since i'm in the TC-team with him we proved to be a very good combination at the last v3c technical day, i'm a bit more practical so i could diagnose very fast and since he has a shitload of theoratical knowledge to back up my findings he could explain the owner what was actually happening with the engine since it was wrong:D

Seems the moderators on volvo30oclub.nl might want the discussion to move back here to the English forum.

punkazz was just fishing for info about the accesibility for foreign (english) users; the way the discussion forms itself at the moment here and at v3c is fine; that way we can all learn from it!

Just to confirm, volvodspec, you were running a B14 4E with a 402 Renix on a CVT car on 95 octane unleaded with no issues of pinking? No C plug earthing at all?S

yup pretty much completely correct

i drove it for a few months as cvt; after that i swapped the entire cvt for a manual 5 speed; no further modifications to engine/ignition and she still ran great on unleaded 95:)

[shimon340]

ok,

I'm going to update the volvo300club post with some scan from some various books etc for discussion. Some extra B14 types in there as well. Seems the conversation in english is ok so long as we're still talking tech stuff!

Given the info to date, a manual B14 4E with a 402 Renix with no amendments to the C plug, shouldn't run well on 95 octane unleaded. Not saying yours didnt but given the tech info so far it shouldnt have been ok.

There might be a curious fact the CVTs had different ignition timing to the manuals (more advanced maps). Can't see a reason for that at the moment though as to why volvo would specify the manuals and CVT maps differently.

[pettaw]

There is a full list of Renix numbers and their relevant cars as a sticky post at the top of this forum.

[shimon340]

Can anyone clarify why it seems to show the AT (=CVT?) having a more advanced map than the MT cars?

[shimon340]

sorry, photobucket hosting has reduced the original quality

[shimon340]

anyone?

[shimon340]

anyone know why the Volvo green books seem to show the AT (CVT?) as having a more advanced map than the MT cars on unleaded.

I'm guessing AT = Auto transmission. Any other suggestions?

[Bossie]

The thread mentions retarding the ignition by earthing pins, would it/is it possible to advance the ignition with earthing pins?

[volvodspec]

nope, C6 and C7 only retard, C8 isn't used on 300's because you can use that for a knock-sensor wich grounds C6 and C7 the moment it detects knock