A moment of apprehension

[Grumblebuns]

 
Spent most of the morning hooking up a temporary battery to my TCS for it's initial road test. For now I've given up trying to safely secure a group 26R battery to the car. I decided to substitute an Odyssey PC680 from my S2 until I can fabricate a more solid battery mounting system for the original battery.

I believe the car is ready to go. I've driven it up and down my drive way a couple of times, so I know that it runs.  This is the TCS that I bought back in the summer of 2013 and spent all this time making it road worthy. For some reason, I have this weird feeling of dread on the eve of it's first road test.

Well, have lunch, have a couple of beers and get over it. Wish me luck.

[BDA]

Hey Joji,

I know exactly what you're going through. That first time is always really anxiety provoking. Since you've driven up and down the driveway, maybe the next step is around the block. Then a little further... From what I know about you, I doubt you missed something and everything is very likely just as it should be. Take that deep breath and let us know how it went.

Good luck!

[pboedker]

Good luck, Joji

Have a nice drive. 

[blasterdad]

Our "moment of apprehension" won't be for a while yet...
I know it will be a "mark the calendar event" though, as I have pushed a Lotus, jacked a Lotus,
wrenched on a Lotus, & got it running, but never DROVE a Lotus...
So, needless to say, It will be a very special day!
Congrats & hope all goes well!

[EuropaTC]

It'll be fine, but just in case you decided to wait until today for the inaugural run, don't forget that essential tool for your Lotus Toolbox.....     

a "Lotus-approved" cell phone !

Brian

ps - well, come on, how did it go then ?

[Grumblebuns]

Well, nothing smoked, caught on fire or fell off (nothing major at least that I could tell). I only drove it six miles total, turned around just before I hit the main road into town. I was pleasantly surprised just how well the car drove. There were two issues that I came across. Going up a fairly steep grade, the car started losing power. Giving it more throttle did not help, had to down shift into second and that was the second issue. It was ridiculously easy to over come the reverse spring detent and I momentarily touched reverse trying to downshift to downshift. The TCS should have easily made it up the grade in third gear.

On the power issue, I'm suspecting that I have to look at the carbs. Either the it's a loose linkage between the two Strombergs or possibly one or both carbs have diaphragm/damper oil issues. The car runs beautifully under low load.

For the hitting reverse issue, if a car ever needs a reverse lock out this one is it. Peter, I have to dig out your reverse lock out kit. I'll try to get to it in the next few weeks. Anyone know if it's possible to install a stronger spring as an interim measure.

Joji Tokumoto

[BDA]

Which transaxle are you using? 365?  My memory with it was that it was difficult to get it into reverse (good) and maybe just as difficult to get it into fifth (bad). If that's what you have, you could put a stronger spring in the reverse/fifth "detent" cam mechanism or shim the spring to apply more preload to the ball that rides on the cam.

Obviously, a lockout is not a bad idea. IIRC, there are some plans for them on the yahoo group.

[EuropaTC]

Well, nothing smoked, caught on fire or fell off

hmmm, (shakes head sadly)  that can't be a proper Lotus you've got there then....   



Actually, that doesn't sound bad for the inaugural run. I always count getting home without pushing it as a win ! 

On the power thing - if the carbs check out, how about a failing coil under load, how many revs did you have on when it started losing power ?

Brian   

[3929R]

Congratulations!

Either the it's a loose linkage between the two Strombergs or possibly one or both carbs have diaphragm/damper oil issues.

When mine had similar symptoms, both carb diaphragms were deteriorated/torn/cracked. The good thing is this is super easy to check and fix.

[Grumblebuns]

I'm still reveling in the moment. A Lotus making it home under it's own power in it's inaugural road test, is almost unheard of.

I'll tackle the issues in a couple of days; the weather is too gorgeous to be stuck in a dark garage. As I hadn't even looked at the Strombergs before installing them, they will be the first item to check out. The car was running before it blew the head gasket for the PO, so I assumed they would still be fine. The coil looks to be a fairly newish Lucas sports coil. No road grime on it so, I'll check that if the carb are not the problem. Going up the hill, stepping on the gas pedal had no discernible increase in RPMs. It felt like the engine just hit the wall around 3k and kept slowing down. On flat ground, I can to push it to around 4k with no hesitation or miss. I didn't stress the engine any further than that.

On the gearbox issue (it's a 365), the ease of getting into reverse caught me by surprise. My original TCS had a stiff detent going into reverse or fifth. I remember that I had to slam the lever against the detent to get into either gear. When I was installing the engine/gearbox assembly into place, I had to grind down of the bolts securing the gearbox to the bracket because it was fouling the down tube on the chassis. I removed the ball and detent assembly to keep it clean of metal chips. I wonder if I lost any shims that may have been in place.

[BDA]

Congratulations on your inaugural run!!! That is really great news! I think I'll throw in with those who blame the carbs. I might check the fuel line for kinks (you do have a metal 'T' between the carbs, right?) and of course, linkage.

I don't think there are shims under the detent spring (I don't remember any or see them in the parts manual, anyway), I just suggested it if other fixes were not practical. Of course, another thing you might do is stretch the spring a little to give it more compression.

Show us the pictures (or did you have a movie crew? )

[pboedker]

Good to hear, Joji. Congratulations!

If the carbs hasn't been touched for a long period, I would also start with checking them. The diaphragms has already been mentioned, but check also that the damper rods move freely and has been filled with oil. Also check for air leaks: The cold start (choker) mechanism, temperature compensator, bypass valve and various idle and mixture screws all must contribute with the right amount.
How about the speedometer cable? is the pedal bottoming out before the throttles are full open? (BTDT)

Regarding the shifter detent, I seem to remember that the housing can be adjusted/moved some millimeters. A quick fix would be to move it closer to the cam and 'to the one side' so that you at least have a strong working cam for the reverse gear. Never mind that it is impossible to adjust it for the 5th gear at the same time, selecting 5th instead of 3rd is only annoying but not critical for using the car. Then you can put some miles on the car, until you find the time to put on the detent parts I sent you.

[BDA]

Before I decided to go to an NG3, I figured I would fill down the cam for the 5th gear detent. I've never heard of anybody doing that, though.

[Grumblebuns]

I managed to get in a quick visual inspection on the Strombergs. All linkages are tight and the shafts move freely. The diaphragms look to be  fairly new. The only oddity appears to be the force required to move the air valve up with finger pressure. It takes a lot of effort and takes a long time (4-5 secs?) to force it up. Looks like it's time to play with different damper oil viscosities to see if that makes any difference.

I did run the engine and checked the operation of the air valve with increasing the RPM. I couldn't see the air valve so I had to stick my finger in the opening to feel if the piston was opening. Slowly running the RPMs up, I could feel the piston fluttering up and down but did not open up any appreciable amount. 

[EuropaTC]

Following on from your latest comments, it does sound like petrol supply is the first thing to investigate.

I have little experience of strombergs, only ever having had them on one car many years ago. I think in those days I just used to put what we called "3 in 1" oil in the carb dashpots, which is a mineral oil and slightly thinner than 20/50. ( I'll also admit to having put plain 20/50 into SU carburettors which operate on a similar damped piston theme    )

I guess the other thing to check is the fuel pump/supply lines as BDA says. If it's been standing the pump might be full of silt or have sticky internal valves ? And easy check anyway with a glass bowl.

As an aside, if you haven't tried a "Gunsons Colortune" plug then I'll admit to being a big fan of such things for diagnosing fuel problems. With one in place it's very easy to lift the revs and watch the colour of the flame, so if it's a weak mixture that's causing your hesitation around 4k then you should see it clearly.  You get similar information from the spark plug of course, but being able to watch the flame at a given rev range is handy if you are checking mixtures through the range - for example checking the needles/jets are suitable.

Brian