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Rough running and other problems

Here’s where to discuss anything specific about your standard(ish) car or something that applies to the model in general.
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TR7_FHC
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Rough running and other problems

Postby TR7_FHC » 01 Apr 2008 15:38

Seems my 78 is in a bit of a mood after i put on 500 miles in a week, now has three distinct problems.

1. have noticed a drop of oil on the drivers carpet, the clutch master is slightly damp with oil so I assume its time for a rebuild (though its working ok at the moment)

2. After driving 100 miles on the motorway without missing a beat when i slowed after leaving the motorway the car began running very rough, as though it was only running on 2 or 3 cylinders, there was no power at low revs, gave it full throttle an it slowly responded, and was fine if revs were kept above 2500. the next roundabout it completly cut out and would not restart without the use of choke. after that the rest of my low speed journey was fine.
(suspecting fuel vaporisation? but would appreciate suggestions)

3. On trying to drive this morning car started fine but severe judder when releasing the clutch, there was a very loud clunk from the gearbox/propshaft area that sounded like metal on metal. later when i went to move the car to my garage to have a look there was no judder or clunk. have no idea on the cause of this problem.

any ideas on where to start looking would be appreciated, thanks in advance.

jclay (RIP 2018)
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Postby jclay (RIP 2018) » 01 Apr 2008 15:55

Clunk: Rear brakes releasing after hand brake has been set all night.

Judder: Is your garage air conditioned? I noticed that when I had my A/C on the clutch would jump/judder first thing in the morning. It would clear up by the time I got to the end of the block.

Oil: Yep, one of your master cylinders is leaking.

Studdering: Haave you rebuilt your SU's lately? Did you top off the damper oil? Next time you drive the car and release the choke, getout and slip your hand under the carb. Push up on the jet body as sometimes one will stick. You would not notice it at half/full throttle but would be over rich at hot idle. Also check to see if carb pistons are sticking.

Have fun, drive fast & safe, be kewl,

jclay
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TR7_FHC
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Postby TR7_FHC » 01 Apr 2008 16:16

Thanks for the quick reply, with regards to the judder my car lives outside as the garage is a couple of inches too short to fit.

Going to try leaving the handbrake off tonight and see if that cures the clonk,


have just checked my carbs and the piston on one seems reluctant to fall back down when it is lifted, the is also quite a bit of sediment in the float chambers so seems its time for a clean.

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Postby Hasbeen » 01 Apr 2008 16:19

If you have points, I'd check them, then the rotor button, & the
distributor cap. Then I'd check the plugs.

I'd then have a look at any inline fuel filter, &/or the fuel pump
strainer.

Hasbeen

moestr7v8
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Postby moestr7v8 » 01 Apr 2008 23:01

check the air filter especially if you have k&Ns, if you have, do you have the correct needles in the carbs?
Just a point as the same thing happened to our 7 coupe just after we got it replaced the K&N filters made a world of difference.
Moe

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Postby trphil » 02 Apr 2008 08:47

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by TR7_FHC</i>

my car lives outside as the garage is a couple of inches too short to fit<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

If it really is only a couple of inches you could put a bulge in the door, I've seen this done before...

gordon kerr
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Postby gordon kerr » 02 Apr 2008 10:36

<font color="green">Although from your description it certainly sounds to be fuel/carb related do check those points first

a) because it's an easy check to see if they have closed up, and

b)becuase TR7s are well known for that problem and 100 miles at high speed on the motorway is exactly the sort of conditions in which it happens.

The description of it feeling like it's not firing on all four cylinders and won't tick over is the typical result.

It's exactly why so many Tr7s have been fitted with aftermarket electronic ignition - even though it's not particualarly difficult it gets tedious having to contiually adjust the points! The right electronic ignition does away with the problem</font id="green">

<font color="green">Gordon
GRD 1980 Brooklands Green 2l FHC
OVC 1980 Platinum Silver 3.9l V8 FHC
Bedford, UK.
</font id="green">

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Postby bottomtop » 02 Apr 2008 22:36

While you are at it, new plug leads may be worth a shot. Small expense but can make a world of difference.

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Postby John Clancy » 03 Apr 2008 08:33

As has already been recommended, check the points. The dwell angle on mine has a tendency to drift and once shot out by about 15 degrees all of a sudden. Also the timing is vital. My own car responds best at around 17 degrees before top dead centre but a standard car should be set to 10. I've had the timing shoot out of whack in the past and the tickover immediately dies.

Electronic ignition is an option but as I've had terrible experiences with it I've stuck with points and condensor but invested in a Gunson professional timing light with built in dwell angle meter. It cost around £100 but was probably the best single tool I've ever purchased for the TR.

<center><b>[url="http://www.triumphtr7.com/documents/sales/codenamebullet.asp"]Buy the story of the Triumph TR7/8 on DVD here[/url]</b></center>

TR7_FHC
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Postby TR7_FHC » 03 Apr 2008 18:02

wow, thanks for all the responses, have not had the chance to do much yet as i am waiting on the clutch parts. I have a new set of points ready to go in, and its due an ignition service.

looks like its going to be a long weekend, at least the weather forcast is good.

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