TurnerX19
TurnerX19 UltraDork
11/27/21 9:57 p.m.

I seem to remember a Lucas alternator that would not charge if the bulb burned out. Check your output first thing when you start up to be sure yours is going to charge without the bulb.

JoeTR6
JoeTR6 Dork
11/27/21 10:17 p.m.

The Megasquirt is showing 14 volts and the gauge 14.7, so it appears to be charging.  Also, I'm using a 1980 Ford Fiesta alternator that uses the same mount and plug as a TR6.  There's a third brown wire going to the alternator to power the field coil on startup.

But I believe that Lucas would do such a thing.

JoeTR6
JoeTR6 Dork
11/28/21 2:46 p.m.

Just one more thing and I'll shut up for a while.  Something I noticed yesterday was that the turn signal indicator was only working to the right.  I forgot that the way it works, current flows either direction through the indicator bulb depending on turn direction.  That doesn't work so well with LEDs (which the new speedometer has), so I put together a diode bridge rectifier and soldered it in.  Works great now.  While I was under there, the brake warning bulb had failed, so that got replaced.  Doing so also restored the oil pressure warning light as they are wired in series.  Low oil pressure lights up both to really get your attention.

JoeTR6
JoeTR6 Dork
11/29/21 8:53 p.m.

Firstly, I need to apologize to TurnerX19.  The TR6 is indeed not charging without that bulb.  I could have sworn I checked it and even had a data log, but that must have been with the lamp in place.  It's pretty awful that if that lamp burns out, it causes the battery to not charge while failing at it's one task of letting you know.  So with the bulb replaced, I figured out that running the vent blower drops voltage enough to shutoff the car.  That's certainly not a good long-term solution.

In other news, I'm now searching for a sporadic coolant leak.  When it happens, it starts dripping coolant fairly quickly under the radiator.  But then it will stop and can't be reproduced.  It's like quantum physics where observing the leak causes it to not happen.  Good thing winter is coming.  I need some time off.

TurnerX19
TurnerX19 UltraDork
11/29/21 11:03 p.m.

In reply to JoeTR6 :

Lucas is not the only alternator to require a functional bulb, but it is the one I saw the most failures on. Only Lucas could make bulbs that bad back then. Now I am not sure they are the worst! Please go Japanese or Bosch, or even GM, they work far longer. Most newer units, especially the one wire ones do not need the bulb.

JoeTR6
JoeTR6 Dork
11/30/21 3:54 p.m.

In attempting to fix the run-on issue, I tried using an LED with a resistor so that it could withstand 12 volts.  That does indeed block current from reaching the ignition switch, but drops the voltage too much (down to 10.8 volts) at the alternator on startup.  Since I don't need the light, maybe what I need is just a diode.

TurnerX19
TurnerX19 UltraDork
12/1/21 11:46 a.m.

Plus 1 on the diode. There have been cars of non remembered make that had just such a thing from new. They would run on when the diode failed. 

JoeTR6
JoeTR6 Dork
12/1/21 1:30 p.m.
TurnerX19 said:

Plus 1 on the diode. There have been cars of non remembered make that had just such a thing from new. They would run on when the diode failed. 

I soldered a diode into a lamp base this morning and it worked.  The only diode I had was just 1 amp max, so I should measure the alternator excitation current before declaring victory and order a pack of 5A low forward voltage drop diodes.  Edit: The alternator is drawing 3 amps with just the key on.

The other thing was jacking up the car to look for the coolant leak.  It appears to be coming from the lower radiator hose, so those connections were tightened.  There was a dried coolant trace coming down the radiator, but that could easily have been a spill from topping it off.  Or cheap Chinese aluminum radiator, so I'm keeping an eye on it.

JoeTR6
JoeTR6 Dork
2/16/22 8:35 p.m.

Not much going on here car-wise.  I'm tackling little issues.  One of these is not being able to see any of the gauges besides the speedometer at night.  There's a guy in the U.K. that sells LED bulbs to replace various incandescents, so I ordered a set to upgrade the gauge illumination and tach warning lights.  Here's the before...

...and after...

The speedometer is using regular incandescent bulbs, but it doesn't have the blue plastic domes covering the bulbs.  Looks like I'm going to drill those out, as half of them are becoming a little opaque.  I also like the warm white better than the blue tinted.  Notice how much brighter the oil pressure warning light is (green LED below tach) .  This comes at a cost.  By putting an LED in that circuit, I lose the brake warning light (big red one between gauges) coming on when the oil pressure is low, and also can't see whether that bulb is still working with just the key on.  I may need to go back to stock for that one.

JoeTR6
JoeTR6 Dork
2/21/22 7:46 p.m.

I pulled the tach apart, took out the blue plastic light filters, cleaned it up and repainted the inside.  The original paint inside had a slight blue tint, but no more.

After putting it back together, I'm happy with the results.  The speedometer has the same LEDs in this picture, and they are almost too bright.

Now I just need to take out the four smaller gauges.

oppositelocksmith
oppositelocksmith New Reader
2/21/22 10:05 p.m.

Nicely done. 
 

I did a similar restoration several years ago on my gauges. 
 

There was a guy that was converting stock rheostats to work with LED's- he did mine and it works great.

JoeTR6
JoeTR6 Dork
2/27/22 6:50 p.m.

Moving on to the next small task, today I experimented with fixing the noisy barometer reading.  Until now, I've been using a 3-bar GM MAP sensor for reading atmospheric pressure.  This car will see up to 12,000 ft. occasionally, and possibly more if they let me drive it to the top of Pikes Peak.  So I need dynamic barometric pressure correction.  I ordered a 1-bar GM MAP sensor hoping it would have less noise in the signal.  It does, and once it was calibrated seemed to work fine.  I did the calibration myself, and it reads 125 kPa at 5 volts.

Looking at the logs after testing this sensor, I noticed something odd.  When the fast idle valve closes at 130F coolant temp, I also adjust the warmup enrichment and cold timing advance immediately to keep the AFR and idle speed steady.  When this happens, the baro reading drops 0.4 kPa.  Maybe the 5 volt reference signal from the Megasquirt changes, but I didn't check that today since I had to let it cool off first and ran out of time.  It's not really that significant, and the baro signal only changes +-0.1 kPa with the engine running now.  Before it was fluctuating +-0.8 kPa.

TVR Scott
TVR Scott SuperDork
2/28/22 11:25 a.m.

Nice job with the sensor calibration.  Tricky.

JoeTR6
JoeTR6 Dork
4/16/22 1:33 p.m.

I still haven't touched the remaining gauges, but I have been on two drives in the past week.  It's still fairly cold here this morning (35F), but that's an opportunity to tune the cold start enrichment and cold running adjustment.  Once warmed up, I got up to 70 MPH and 5600 RPM.  The only not-so-great thing is the oil pressure dropping below 50 psi at higher RPMs.  It's fine for the first 10 miles, but after that it's 55 psi according to the mechanical gauge and fluctuating between 48 and 60 psi based upon the AEM pressure transducer.  What's strange is the high frequency of the variation, roughly 0.3 sec per cycle. It's also worse with increasing RPMs, so I suspect the sensor is still picking up noise from the adjacent coil.  I reduced the minimum oil pressure warning threshold at higher RPMs slightly to stop triggering the check engine light.

Other than that, it just works.  Power off the line is good, but it feels weak at higher RPMs.  The altitude was around 7300 ft., so that could be a factor.  At 5600 RPM and 50% throttle, the ignition advance is only 35 degrees (fairly conservative initial tune).  Hopefully it will wake up with some more advance.  Maybe it's time to find a tuner shop with a good dyno and Megasquirt experience.

JoeTR6
JoeTR6 Dork
4/29/22 11:04 p.m.

I've been putting off finishing up a few things on the TR6.  One of these is installing the vents under the dash.  Yesterday I powdercoated all of the pieces, and today the clamps got a soak in some Evaporust.  Hopefully this will be finished over the weekend.

JoeTR6
JoeTR6 Dork
5/6/22 10:01 p.m.

Before I could put the vent ducting in under the dash, the windshield rake needed another adjustment on the passenger side.  All of the hardware fastening it down was loosened and the windshield tilted slightly forward.  It's better now.

With that done, the ducts were installed.  It will be nice to have controllable fresh air this summer.

Next up is recentering the steering rack so that the wheel can be straightened.  While the front is up in the air, I'm going to mount all of the six stock steel rims that I have on a known true front hub and check them for bending.  I need a spare at the least, but it would be nice to have a complete set.

JoeTR6
JoeTR6 Dork
5/8/22 8:57 p.m.

I got the steering rack recentered and only had to remove the rad fan.  Before loosening the rack mounts, the mount spreader was installed and tightened.

After putting the fan back in, I realized that the spreader tool was still in place.  Oops.

The first wheel that was checked for trueness is quite lumpy.  Good enough for a spare, maybe.

oppositelocksmith
oppositelocksmith New Reader
5/8/22 10:46 p.m.

After moving to alloys, I was blown away about how egg shaped my stock wheels were!

JoeTR6
JoeTR6 Dork
5/9/22 10:59 p.m.
oppositelocksmith said:

After moving to alloys, I was blown away about how egg shaped my stock wheels were!

I checked the other 5 wheels today.  Four where decent with a few high or low spots each, but basically round.  Two are very beat up.  Maybe I'll just use up the 200tw tires on there now (they are nearing 4 years old) and use the best steel rim as a spare.

I took the car out today to check the steering wheel angle.  It's close enough to straight.  The speedo was also fine tuned to read within 1 MPH at 75.  Traffic was lighter than usual, so I got to take a few on ramps at speed, and the handling is quite grippy and neutral.

JoeTR6
JoeTR6 Dork
5/11/22 6:12 p.m.

It occurred to me today that the cost of having a stock steel rim powder coated is about half of what a brand new Rota RB wheel costs.  Since I don't have a good 5th wheel to use as a spare, I'm going to order one Rota RB and use that as my spare or replacement wheel should I bend one.  The 4 decent stock rims will get saved for my brother since he has one as a spare.

So what's left on this project?  Not much.

  • Source a spare tire
  • Put a toolkit in the trunk
  • Finish the alignment (although it's pretty close)
  • Put LED bulbs into the 4 center gauges

At some point, I suppose I should try autocrossing this thing.

JoeTR6
JoeTR6 Dork
5/14/22 4:10 p.m.

I'm working on acquiring a spare, but Rota threw me a curve ball.  It appears they changed the center cap and center hole design over the last four years to be larger so as to fit more cars (some old Ford).  So my plan to buy a new Rota RB will either end with a wheel that has a larger center cap  or one that is black (with the polished rim, at least).  I won't notice the black rim in the trunk, and can have the center part painted silver if need be.

There was much procrastination with putting LED bulbs into the middle gauges, and for good reason.  That is a terrible job if you need to remove the gauges, which I did to remove the colored light filters.  Getting to those little knurled thumb nuts is just no fun.  This time, I broke the heater fan switch while jamming my hands behind the dash.  The black plastic body separated from the metal part that goes through the dash.

When the switch came apart, some of the small internal pieces flew out.  I found everything but one small spring.  Good thing I bought a similar china-made switch that doesn't work, because at least it has the same springs.  Taking that switch apart convinced me I didn't really want electrons flowing through it anyway.  So the original Lucas switch lives on.

The car is back together and another task is off the list.  And my hands are quite mangled.

oppositelocksmith
oppositelocksmith New Reader
5/14/22 5:23 p.m.

Behind the dash work definitely is no fun!

I hope your battery was disconnected when that switch came apart. It's the wiring harness killer!

Have you tried putting one of your Rotas in the spare well yet? Sure sounds like a tight fit regarding width.

JoeTR6
JoeTR6 Dork
5/14/22 6:42 p.m.

In reply to oppositelocksmith :

I've learned my lesson about digging around in wiring without disconnecting the battery.  Before putting the panels back in, the wiring was tidied up, wrapped, and zip-tied better to avoid any shorts.

A 205 width tire will fit in the trunk, but that's with a 6" wide rim.  Good point.  I'll do a test fit.

JoeTR6
JoeTR6 Dork
5/15/22 11:48 a.m.

I've got good news and bad news.  The sticky tires will fit in the trunk with some persuasion.

But it won't quite lay flat in the bottom.  I suppose not all 205 width tires are the same, and the 7" rim widens it slightly.  This will work if the right 195 width tire is mounted as the spare.  Carrying the flat tire might be an issue, but it could fit behind the seats.  Leaving an unobtanium tire and wheel by the side of the road would be bad. So maybe I do need the steel rims for touring.

oppositelocksmith
oppositelocksmith New Reader
5/15/22 5:16 p.m.

I'm glad you checked. 
When I went 15x7 with 205's, I remember a similar issue (it's been about 7-8 years now). As a result, I converted to a space saver spare for my car and a flat deck trunk board. 

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