Unleaded fuel

[Freepress]

I have a 1988 16 trs, carb will this run ok on unleaded or do I need to make adjustments, if so what do you suggest

[DLM]

As far as I remember, it's pre-1988 cars that would require LRP or modification,but on thinking about it the info is here

http://www.tramontana.co.hu/citroen/fuel/fuel.php

I there's a tag somewhere on the engine to distinguish the exact variant. On the other hand, what's it been running on since 2000?

[Aerodynamica]

Wow, stop the bus! according to that chart I ought to move my ignition 8? at 850rpm to run on unleaded (and presumably also need to adjust for LPG which it runs all the time)

What would be the symptoms/ damage of leaving the ignition unchanged?

[mat_fenwick]

You might be more prone to pinking running on 95 octane unleaded without retarding the timing, but if you never load the engine running on petrol, I wouldn't worry about it.
With it being fuelled by LPG I should imagine that you can run significantly more ignition advance, to minimise the power loss when you switch over (slower burn with LPG). That's certainly the case with our Discovery. My advice would be to see how much advance you can get away with on LPG (advance the timing to it just pinks going uphill in top, then retard it a tad), and hopefully it will be acceptable simply starting it on petrol, and switching over straight away. You may have to experiment a bit to get a suitable compromise, and if you do run out of gas, be gentle running on petrol!

[DLM]

When looking at the chart, I did recall the F-reg 16RS I ran on LRP for several years with a replacement engine from a very early BX.

I did also wonder about some of the older BXs owned on this forum... though I gather it's a problem most often associated with hard driving or overstress, and an untouched head may have what's called "lead memory".

Valve seat recession on a Volvo engine here

http://www.georger.com/gds/unleaded_gas.htm

[Kitch]

AFAIK the only petrol BX designed to run on 4 star was the pre-knock sensor 16v. Everything else was unleaded.

[DavidRutherford]

If memory serves, I think the suitcase engine'd BX 14 was also supposed to be a 4-star only fuel engine.

Yet another reason why they're a bit on the rubbish side.

[DLM]

You have a point there, Kitch - though it's the suitability for octane rating in the chart, rather than suitability for unleaded though, now that I look.. my mistake.

This one, a bit ancient, has some more suggestions, and unadjusted and adjusted timing advance.

http://www.citroenet.org.uk/miscellaneo ... eaded.html

That replacement engine I ran came from a very early BX16 - something like '83 on an A-plate (I saw the dark blue BX it came out of which was about 12 or 13 years old at the time).

It was fitted by an independent Citroen outfit, and at a the time I didn't ask as many questions as I would do now. They insisted that very early XU5s in BXs were not designed to run on unleaded. There's a post on the auusiefrogs archive where someone quotes specs from an ELF document saying that BX16s before 84 weren't suitable for unleaded.

While the engine was being fitted they lent me another Mk1 BX - a bright red 16TRS on a C-plate if I remember rightly, with no instructions that I recall to avoid putting unleaded into that one.

[kiwi]

I have a 1988 16 trs, carb will this run ok on unleaded or do I need to make adjustments, if so what do you suggest

Quick answer is Yes and more than likely has been run on unleaded for several years already. When you say Unleaded you mean the 95 Octane cheaper of the two brands of Unleaded in the UK dont you?

If you detect any pinking noise then have the timing checked for piece of mind.

The Only BXs I was aware of that could not use unleaded was the BX16 Valve and pre 1988 BX14.

Saying that theres a few BXs 16Valve in New Zealand and prior to 2003 the highest octane fuel was 95 Octane and ever since 1996 has only been Unleaded. Which does go on to explain why so few and no BX14 unless imported from ex pats.

Always remeber this debate with a mechanic way back in 1993 when he told me flat that my BX could not use standard Unleaded even though the book said it could because of the low Octane rating. Funny how in NZ they only had 91 or 95 octane fuel up until 2003!

Even now you get the Petrol heads on the forums in NZ telling you that you cant use 95 in a car or asking if they can use 91! Thankfully you dont have 91 octane in the UK and no the BX dont run to well on the stuff.
Unlike Jappa crappers that run on the cheap stuff!

A higher octane rating ie Super Unleaded 98 which has been on sale in the UK since 90s as well and was the stuff they brought (or similer) as in NZ. Provides a better fuel consumption! That in my view has to be weighed against the cost v extra miles you get per litre.

Unfortuantely where I live I can not source a regular supply of 98 to be able to test that theory out! The one time my BX did use the stuff was the day I got it.

In case you guys are wondering I worked for a couple Oil Companies back in the UK for several years thats why I know my Fuels to use in the BX

[Tim Leech]

I have a 1988 16 trs, carb will this run ok on unleaded or do I need to make adjustments, if so what do you suggest

Ive run all my BX petrols (1985-1993) on unleaded with no problems, but the 14E (suitcase engine) had a "fuelcat" fitted in the fueline. The 16TRS Auto had a little sticker on the engine saying "adjusted for unleaded" so as mentione above you may need to alter the timing to stop it pinking.