TR5/6 Starting Problems

[matthewpetzold]

I've seen and followed the advice of so many queries on this forum relating to starting difficulties with the PI engine that I thought it worth posting my most recent experience on the subject.

 

After years (yes, years) of apprehension before every cold start, I turned to the only item on the car related to the starting procedure that I had not previously changed - the battery and hey presto, the problem was solved in a trice.

 

To be clear, the battery had been replaced a while ago, but I had paid no particular regard to its performance characteristics, just so long as it was the right size and "looked right" under the bonnet. It was always capable of turning the engine over so never occurred to me that there might be a problem.

 

The moment of realisation arrived at Goodwood's recent 73rd Members Meeting when I went to leave at the end of the day and despite repeated attempts the engine would not start and the battery eventually died. Luckily a friend had a jump start power pack on board which he had recently fully charged. We applied this to the problem and the engine fired first time.

 

I immediately researched the issue and discovered that the jump start in question had a cold start rating of some 500 CCA (cranking amps I believe) - next stop was batteries, and mine turned out to be rated at 265 CCA - not great. It turned the engine over well enough, but did it have enough oomph to drive the fuel pump properly as well ? I plumped for a LUCAS replacement, their top of the range battery is called FUSION, and the one which will fit a TR5 or 6 is the LF096 model. It costs £140 but more importantly has a cold start rating of 760 CCA - bingo, my car now starts every time on the button, it is hard to exaggerate the difference this makes to the whole experience of driving it ! - I know that £140 is quite a lot of money for a battery but in the scheme of things and considering what else I have spent in my attempts to cure the problem it is well worth it.

 

I presume the issue with the PI engine is compounded by the need for the fuel pump to be able to draw sufficient current to provide the necessary fuel pressure to enable the engine to fire. A lesser battery may appear to be spinning the engine well enough but is this at the expense of the fuel pump's requirements - I'm no technical expert, but this explanation seems to make sense to me.

 

Please note that the battery recommended LUCAS LF096 has terminals the wrong way round for a TR (like 95% of today's batteries), but will fit easily enough with the terminals to the rear next to the bulkhead, the battery leads are long enough for this (well, mine were). It is also light (and therefore non original) in colour - easily remedied by a couple of coats of satin black before installation, together with one of those LUCAS battery stickers sold by Moss.

 

Hope this is of some use to somebody.

 

Matthew

[JohnG]

Matthew

+1 for a battery with plenty of cca!

 

I had cold start problems and did all the things suggested by the forum, all of which helped.

 

When my battery died, I again turned to the forum and followed the advice;

As many cca's as I could get (in my case 620) in a battery that fitted and had the terminals the right way round

 

Starting is greatly improved, still not perfect (it's a 1975 BL car after all), but learning that it's cca not Ah that count was a revelation

 

All power to the the forum I say!