No replies first time so in case it got lost, here's the question again...
I have a choice concerning my car and I'd appreciate any collective or
collected wisdom....
The car is a 1972 2.5PI Saloon, with the 134bhp fuel injection system. The
system is currently still wrong, making the car run on less than all
cylinders. The cause appears to be the metering unit seals breaking up and
passing into the injectors, jamming them. Although a little noisy on start
up-probably endfloat- the pump has never vapour-locked or caused any
problem. Currently, though, I can only lose the 'misfire' feeling for about
twenty minutes after I've stripped and cleaned the injectors. Consequently,
the output feels nothing like 134 bhp.
The choice I have is to either fit a reconditioned, unleaded spec. metering
unit and have the injectors cleaned and calibrated.
Incidentally, I'm told the unleaded specs MUs just have improved
seals/diaphragm, the standard rotor can cope with unleaded fuel. My
injectors were reconditioned at 37,000 miles and the car has now done
58,000.
The alternative is to recondition and fit a pair of SU HS6's and manifold
which came off my 2.5S donor car.
Each option would probably cost about the same.
What concerns me is that I have spoken to several owners/enthusiasts re. PI.
Every one has mentioned that the PI system is great when it's working but
that it goes off tune very quickly, i.e. in a couple of hundred miles. Also,
many PIs were converted to SUs, apparently for the same reason.
The opposing school of thought says that carbs will drastically cut power
and are far less effective.
For my part, I have driven a Mk.1 2000, whose power delivery was
consistently silky smooth-which made me envious. However, at 90bhp, this car
did feel underpowered.
So, does anybody have experience of these things? Can anyone give me pros
and cons?
Any information/opinions gratefully received.
David Hill
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