LRP - Unleaded

[tbourner]

My Renault, it's an 1108cc Campus, F-reg from 1988.

 

Would that have been 4-star originally?

 

 

Basically I never bothered to ask the owner which fuel it takes, my dad just said put unleaded in so I have been, is it likely to have been converted if it was 4-star?

 

It's been running bad, we found out the timing was out by some silly amount (looked like about 10 degrees!!!!), sorted that and got new points/condensor/plugs/leads etc. but it still runs pretty badly, still overruns slightly when I shut down, smells of fuel after switching off....

 

 

 

Should I try some LRP? What are the problems with using unleaded in a 4-star car? What about using LRP in a converted unleaded car?

[Lucifer]

My Renault, it's an 1108cc Campus, F-reg from 1988.

 

Would that have been 4-star originally?

 

 

Basically I never bothered to ask the owner which fuel it takes, my dad just said put unleaded in so I have been, is it likely to have been converted if it was 4-star?

 

It's been running bad, we found out the timing was out by some silly amount (looked like about 10 degrees!!!!), sorted that and got new points/condensor/plugs/leads etc. but it still runs pretty badly, still overruns slightly when I shut down, smells of fuel after switching off....

 

 

 

Should I try some LRP? What are the problems with using unleaded in a 4-star car? What about using LRP in a converted unleaded car?

 

 

YEs sounds like an LRP and timing issue. You may want to put that timing back tho if its been converted to LRP

[tbourner]

err, no I mean if it originally ran on 4-star and hasn't been converted to unleaded then I should be using LRP and still have the correct points and timing as the book states (LRP replaced 4-star - they're the same!).

 

If it's been converted then the timing may have been adjusted, but why was it running really badly and now is running better since adjusting the timing?

 

 

Basically the timing now seems good, but have I done any damage running unleaded if it's meant to be 4-star/LRP?

And would I do any damage if it has been converted to unleaded and I decide to put some LRP in and see what happens?

[TrickTT]

lead in petrol lubricates the valves. An unleaded cylinder head has hardened valve seats to compensate. if you've been running a unleaded on an engine with non hardened valve seats you will eventually end up with leaky valves - do a compression test. The timing only needs to be adjusted to compensate for the different octane rating of unleaded (95RON) compared to old style 4star (98RON)

[tbourner]

But would a '88 Renault be 4-star or unleaded anyway?

 

What's a compression test and how do I do it?

[TrickTT]

1. no idea, could be either, best bet would be to check with Renault

2. you need a compression tester which screws in the spark plug holes, to be honest if you have to ask you would probably be better off getting it done by a garage

[tbourner]

I understand the principles just never done it. How much and where are testers available from? Any tips like put each piston at BDC before the test?

[garethr]

If the unleaded has affected the cylinder head, it's likely to have caused the valve seats to wear excessively. Have the valve clearances closed up?

 

You could use LRP in a converted engine (no cat), but there would be no point. Apart from anything else, I can't remember the last time I saw LRP.

[TrickTT]

I understand the principles just never done it. How much and where are testers available from? Any tips like put each piston at BDC before the test?

Halfords sell them for not very much money. Just disconnect the coil, remove the plugs, one at a time, screw the tester into the plug hole and get someone to turn the engine over on the starter a couple of times. You will be looking for low/inconsistant readings.