My '72 P6 V8 is back in use on UK roads and once again wearing its silver on black 'K' plates!

My old banger set a new record today; it was the first time I've had to make three calls for roadside assistance in just one week! It seems that the alternator isn't returning any charge whatsoever to the battery, which I must've run pretty much completely empty before finally conking out. No chance of restarting, it barely turned the engine over once. The lesson learnt being not to just ignore the red IGN light if it stays on and keep driving on regardless. :rolleyes:
The lingering but faint burning smell, which I had wrongly attributed to the shiny silver high temperature paint I used on my freshly refurbished exhaust, was probably the alternator melting down inside, or something! Hindsight is marvellous. Having checked and re-checked that it wasn't my fuse box melting again I had just carried on motoring, thinking that pesky burning smell would soon go away. Doh! :(
I do hope I can charge the battery back up and carry on using it, and that it isn't now knackered. Here's also hoping the alternator can be repaired. I'll report back on Monday, after I get a professional diagnosis. Guess I'll be back on my bicycle this weekend. Serves me right, I suppose.
 
Sorry for introducing a side note. Maybe there should be a “what have you ignored” thread. Mine was a knocking noise from the rear (on the interstate 5 freeway). So I thought, “let’s just get to the next exit”......then the wheel fell off; fail. Theres a first and last time for everything.
 
The non-charging problem turned out to be the dodgy state of the wiring behind the alternator. The two old connectors weren't gripping the spade terminals on the alternator tightly and the wiring had more-or-less disconnected. The insulation was also a bit cracked just behind the connectors, from bending the wires tightly to locate them in the small gap between the back of the alternator and the front of the valve cover. New connector for the big brown and white wire with a neat 90 degree bend, and a plastic reinforcing piece around the connection of the smaller wire, and all is well again. Battery hadn't completely lost its charge, and the alternator fortunately seems undamaged. Now I just need to locate where that faint burning smell is coming from! Maybe it really is just the exhaust paint after all?
I was disappointed to find another fresh small puddle of coolant collecting on top of the timing cover, next to the distributor. I think it is coming up and out from the waterway seal between the timing chest and the engine block. It doesn't look like it is coming down from the front valley gasket seal, or the front end of the intake manifold gasket at the head, as was the case before. Nor from any of the hoses above the front of the engine. It seems to be 'weeping' as opposed to really flowing, so I'll live with it for now and keep a close eye on the coolant level. I really want to enjoy driving the car for a bit now, before I have to do any more spannering!
Furthermore, the ghastly groaning noises the front suspension used to make really do seem to have been banished by fitting a new steering idler! I had feared it was the rubber bushing on the end of the actuating rod inside the front road spring, and that I would have to dismantle the front suspension to replace them. In fact the noises must have been coming from inside the old and bone-dry knackered steering idler, and the sound was somehow being transmitted along the steering side arm and through the road spring. So that is a big win. One more job thankfully crossed off my long to-do list. :)
 
500 miles since I swapped the manual transmission in and I can now say for certain I don't regret it! It is now quite hard to remember to exercise restraint and drive in a civilised fashion, the temptation to be a hooligan being very difficult to resist. The faint burning smell was indeed the exhaust paint bubbling before flaking straight off the front section, but hey, who's looking down there anyway, right?
Where the right down pipe joins the front section there is a small blow, which makes for a nice loud exhaust burble! Would wrapping it in heat tape, because it is actually very close to the clutch slave, also muffle the noise a bit?
 
Well done on the LT77 install, makes it a lot more civilised at speed.

Personally, I would fix the blow first, then wrap it if you need to. You don't want any exhaust fumes getting into the car.

Richard
 
So summer traffic jam fun time again. Sigh. Why does my idle speed, when inching along in a heavy jam, slowly but inevitably go from the 600-odd rpm I would prefer up to as much as 1500rpm!?!? Because it is twisting my brain and waiting for everything to cool down and all the other motorists to clear off the streets is testing my patience. I've ordered a Pertronix Ignitor to replace the points and I'm hoping that fixes it!!! Hints and tips for steady running most welcome!
 
Hi Harvey. Nope. No poppet valves. Let it cool for three quarters of an hour in the shade with the bonnet up and it started back up at a nice gentle 600 rpm again.
 
I suppose that you are running HIF6s?
What is your mixture like at 600 rpm conditions? Maybe it is too rich, and when hot the jets are trying to lean out/correct the mixture ratio, hence the higher idle speed.
 
As we're all guessing I may as well stick my 2 cents in. The fact that the problem arises in slow moving traffic (so no wide throttle openings), and it gets worse as the temperature rises, and conversely improves and disappears after a cooling down period, assiming the carbs are HIF6, I'd look at the bimetallic strips on the jets.
 
HIF6 breathing through a NADA airbox, with a warm air collector from the drivers side exhaust manifold and a cold air snorkel from the long central bonnet scoop. Carbs got all new seals the other year. Coolant system in fine form, uprated thicker rad with a good pressure cap plus a Kenlowe fan on the front, mechanical fan removed. No coolant loss since I fitted new composite cylinder head gaskets using new head bolts last year.
Thanks for your suggestions everybody. My mechanic wants to have the car displaying the symptoms so he can more accurately diagnose the fault. To achieve that do I just leave the car sitting idling on a hot day until it warms up enough to start playing up?!
I'm going to dig out the workshop manual now and look for those bimetallic strips you suggested, Harvey. I know there's one inside the airbox, getting a vacuum signal from the intake manifold and from the vacuum can on top of the airbox snorkel, and supposedly adjusting the mixture flap accordingly. But "bimetallic strips on the jets" has me confuddled right now!?!?
 
Easy enough to do Jim. I'll concede in advance I'm probably just dim, but how/why would warm air to the intake make the revs rise like that?
 
Easy enough to do Jim. I'll concede in advance I'm probably just dim, but how/why would warm air to the intake make the revs rise like that?
It wouldn’t usually, heat tends to enrich. But there’s so many variables and it appears heat related, thought it was an easy thing to start with and test.
Jim
 
So despite checking and re-checking a great many times that there was sufficient clearance for the throttle and choke mechanism to work without being impeded by the warm air hose, I couldn't find the cause of my sticky throttle. I decided to remove the whole airbox and elbows and replace them with some conical K&N filters I had forgotten about and found in a box of old bits'n'pieces.
Oh my goodness! What a difference to throttle response and what an absolutely awesome noise it now makes! Unbelievable. From woofly (how do you spell that?) and discrete, to loud and raspy and utterly naughty racing car. I hadn't realised the NADA air intake set-up was really still restrictive in comparison. Best fun ever, this old car, but I have a feeling if I carry on being very enthusiastic off the lights I'm going to break something and/or lose my licence, so I'm trying to remember to remain calm and civilised and gentlemanly. That brutal noise though. It is addictive!
 
I do love a bit of sustained WOT :p
But yeah, definitely check your mixture with all that lovely air :)
 
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