Pete & Aprille Chadwell Wrote:-
>Date: Tue, 19 Jan 1999 15:36:27 -0800
>From: Pete & Aprille Chadwell <dynamic@transport.com>
>Subject: TR6 still running poorly <Part 3>
>The symptoms: Again, this is intermittent. One day last week I drove 25
>miles out of town to see a client and it ran beautifully all the way. But
>it skipped and sputtered all the way home. It doesn't slow you down all
>that much... I could still go 50-55 mph, but if you dip into the throttle
>at all it skips and sputters and pops out the tailpipe. Not a backfire,
>but just a mild poppity-pop sound when trying to accelerate. I say
>"sputtering" because it seems random and irregular, not like a misfire
>where the same cylinder is dead every time around. If you have to go
>uphill it can slow you down, though... if you give it much load at all
>it'll pop and sputter in any gear, especially top gear, and take you down
>to 25 mph. Then the next day on the same hill it'll pull strong and
>smooth
>all the way up. Generally, when it's misbehaving you can minimize or
>avoid
>it altogether just by keeping an even throttle. But the minute you
>accelerate it'll pop and sputter again.
>Any suggestions?
Here goes,
I am no expert on the TR6 but your symptoms are classic for fuel starvation
because of restricted flow rate. I had exactly this problem on my V12 Jaguar
after I put it on the road at the end of a long lay-up. The actual culprit
in my case was the very fine nylon mesh pre-filter on the pick-up tube in
the fuel tank. All fuel systems have filters to protect the pumps, jets etc
and these can be easily blocked by fine dust or rust particles. Often these
particles settle in the bottom of the tank so you may have no problem at the
beginning of a trip. After a while they get sucked onto the filter mesh and
cause flow restriction and load dependant misfiring. The particles may or
may not fall off before you use the car again, hence the erratic behaviour.
A good test to confirm the problem is to put a pressure gauge on the fuel
line. If pressure drops when the symptoms are present you have got it!
Filters are often partly blocked with varnish, sludge etc and any extra
restriction is the last straw. Of course your problem could still be a
failing pump or other related part but I am certain it is fuel related at
least.
Peter French
1969 GT6
Bedfordshire, UK.
|