-----Original Message-----
From: Terry & Cindy O'Beirne <esp@hypermax.net.au>
To: triumphs@autox.team.net <triumphs@autox.team.net>
Cc: DavHill@email.msn.com <DavHill@email.msn.com>
Date: 25 February 1999 20:25
Subject: PI vs carbs
Hi, Terry & Cindy,
You are quite right, there is some bullsh*t being talked about PI. Thank you
for your forthright approach :-)
Tell you what, let's play Q & A.
>Dave, I posted a long dissertation on PI woes some 4-6 weeks ago. Who
>ever you are talking to is teliing you a pile of &%**@@##.
Agreed!!
>Many PI systems work just fine on unleaded without ANY change at all. It
>appears to be linked to exact petrol brands. I cannot give specific
>advice.
There's the risk.
>The specific problem indicates you have the "bung seals" behind the
>outlet fittings breaking up. You can changfe these yourself with a
>little bit of care and lots of rubber grease. read the manual!!! Any
>large triumph parts supplier will stock them. The latest spec (nitrile)
>rubber ones are best with unleaded.
Q1. If the bung seals are breaking up, is it reasonable to assume that the
rotor seal and diaphragm are in a similar state?
Q2. I have read the manuals (Haynes and factory). I can get the UL spec
rubberware from Pumford's in Wallasey and reckon I could rebuild my own
unit. What do you think?
>A correctly set-up PI cannot go Off in weeks as suggested. This is
>absolute rot and dispays ignorance on the part of the offeror of the
>comment. I have fixed them since new , having done the Lucas training
>course when PI's were still sold new. My TR5 has not been touched
>in the PI area for over 50,000 miles!!.
This was from a chap who used PIs in their heyday but did not work on them.
Here's a quote from the 'Motor' Road test (No. 27, 1974), of the 2500TC.
"Basically, it's a 2000 fitted with a twin carb version of the ageing
2,500cc engine (until now only available with Lucas Fuel Injection). It
should thus appeal to the buyer who wants a little more performance than
that offered by the rather lethargic 2000, without the additional expense,
fuel consumption or bother of the (by reputation) somewhat troublesome fuel
injected car.
So, is this just a system of ill repute? Were BL just saving money by using
carbs?.
Incidentally, one the specialists asked me what make my system is. He said
that some very early cars had Bosch injection. First I've heard of it.
>Mostly, the problems stemmed for poor/wrong repairs by well meaning
>mechanics with no PI skills, and/or non PI related problems like
>worn-out Lucas ignition distributors. basically, thru the 1970's , they
>experimented on owners. Owners on the other hand had never had to spend
>so much money on a "carby" and were completly unprepared for large bills
>associated with fine tolerance (diesel style) equipment.
My mixture datum track has been played with in the past and what with that
and leaky O rings inside the injectors it could not better 16mpg when I got
it. It's now around 26 mpg regardless of how its driven. It just runs like
a dog's breakfast.
My only real concern about rebuilding the unit myself is the detection of
whether the rotor/body condition and tolerances are correct. Is there a rule
of thumb means of passing or failing the parts, e.g. presence of scores, how
serious, etc.?
Pumford's rebuilt units are set up on the genuine Hartridge equipment.
They've already said they'll clean and calibrate the injectors so they might
also set up the MU. Having said that, I do have the vac
settings/measurements from Egil Kvalberg.
>Once you fix your bung seals, you should reclean the injectors with low
>pressure compressed air (gently), and all should be well again.
Fair enough
>Be patient & dont convert to carbs
This is more about convenience and cost than patience. I got a pretty fair
pair of HS6s from the scrap 'S'.
Thanks for your input, Terry & Cindy (and the others).
I look forward to your reply.
Dave Hill.
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