GT6 Zero acceleration power / Car’s RPMs surge when you get in it.

[dklawson]

If I am reading your post correctly, the engine will idle fine but when you remove the damper from the top of the rear carb (not doing anything else) the engine wants to die. Is that correct?

If you unscrew the damper slowly and remove it slowly does this happen? Do you have oil in one carb and not the other? During installation of the new diaphragm did you make sure both its tabs were in the corresponding slots of the piston and carb body? Unless there is a good sized air leak, if you were running molasses instead of oil in the dashpot, I cannot see why removing the damper should cause the engine to die.

Those test wires are inserted and removed with the engine "off", NOT with the engine running. The height of those wires indicates how high the piston is in each carb. When the wire tips are at the same level the carbs are sucking equal amounts of air. You insert and align the wire tips to each other with the engine off the air pistons are resting on the bridge of their carb. That is the baseline... both carbs sucking Zero air, both pistons on their carb's bridge, wire tips pointing at each other. Once the wires are inserted and aligned do not touch or bump them again until the carbs are balanced. Start the engine and notice where the wire tips are relative to each other. Use the idle screws on both carbs as necessary to change how much air each carb is pulling. You will notice when you turn a carb's idle screw speed screw in, the carb piston (and pointing wire) go "up". Tweak either/both of the idle speed screws until the wire tips point at each other again with the engine running. Once they are pointing at each other, tighten the linkage screws and adjust the idle screws equal amounts to get the idle speed you want.

 

[UmmYeahOk]

Ok, so that seemed to be it. Somehow, by taking the dampers out and using the coat hanger tools several times, I removed too much of the oil. Oh yeah, and I cleverly dropped both dampers onto the saw dust covered floor. I had enough sense to wash both off before returning them back into their homes, but probably removed whatever excess oil was on them. I added oil back into both, and I think they both now work fine. I can now rev beyond 5500 RPM in neutral.

I was able to test drive the car just now. With it being 90 degrees out, in direct TX sun, the only way the car would start was with the choke fully closed. I drove it down the street and back and the power seemed a bit lacking from what I remembered when picking it up from the shop last January. The car also began to overheat, so I pulled back into my driveway, but then the temp gauge went back to the middle. So I pulled back out to see how it would handle farther. It began to overheat again after passing just one house, so I drove it back to my garage and called it a day. These two trip were extremely short distances, though up hill.

PREVIOISLY: While I was diagnosing my carb trouble, I noticed the car would overheat. I then learned that there was hardly any coolant in the radiator!!! I know it had to have had at least some because there was no way it would’ve survived the drive from the shop back to my house during rush hour traffic. So where did it go? It was no where on the floor of my garage. And I inspected the underside of my car that one time I drove it to the drive in restaurant, since I was looking for other issues.

Also, I previously mentioned a jet being soaked in gas... ...I think it was just flooded, as it never again did that.

So parked, car seems fine, also doesn’t overheat any more. But driving, it’s under tremendous load, and the car quickly overheats and loses power. At least today was a mild success.

PS: I was pretty sure I burped the car well after adding the coolant, so I guess those fail safe thermostats failed again. Haven’t experienced this with the Triumph, probably because I never drive it, but my mustang goes through one every two years!!!

 

[trrdster2000]

Thanks for the update and you are heading in the right direction.
New thermostat should help, most run the 186 degrees or close to it. Good chance the shop didn't fill it up and you were running in cooler temperatures.
Progress.

 

[dklawson]

Does the car have the overflow catch bottle connected to the radiator filler neck? If not, look at a parts catalog to see the plumbing connections, then fit a catch bottle and connect it to the radiator filler neck with a hose. The hose has to go in the catch bottle and all the way to the bottom. Fill the radiator to the top, fill the catch bottle half way, and fit the radiator cap. The car will burp out excess coolant into the catch bottle when hot. That fluid is then drawn back into the radiator from the catch bottle when the engine cools down. Without the catch bottle the hot coolant is dumped from the radiator (probably while you are driving) and when the engine cools, the system draws in air instead of water/coolant. You can improvise a catch bottle. Assuming you have the bottle bracket, any bottle that will fit in the bracket will work. Just remember the hose from the radiator must go all the way to the bottom of the bottle.

It could also be a faulty thermostat as you and Wayne discussed. You do not have to order a special British part, go to the local parts store and tell them you want a thermostat for a mid-1970s GM car... like a Camaro. It will fit perfectly. You can test a thermostat by placing it and a thermometer in a pan of water on the stove. Turn on the heat and watch the thermostat. When you see it open, note what the thermometer reads. The thermostat should open within about 5 degrees of the setpoint stamped somewhere on the thermostat's flange.

The oil in the dashpots should only cause the engine stalls you were experiencing if you are using some REALLY thick oil. I was thinking that the oil would have to be SO thick that removing the damper pulls the air piston up causing the mix to go lean.

Even though the engine is now ready to rev higher, the lack of power may still be due to the mixture not being right.

 

[UmmYeahOk]

Update:

Car has had an overflow bottle, but was not filled at that level. It came with the bracket, but the bottle I had to buy a decade ago

I flushed the radiator and engine, added new coolant, new thermostat. They’re cheap enough and fail so often that I didn’t bother testing the old one. The old one was covered in rusty fluid anyway. The coolant system was not touched by the shop, but by us, and less than a decade ago. I appreciate the GM reference, and brought my old thermostat with me to compare, but they had one listed for my car in stock. It is for 160 degrees instead of 180, as those required special ordering. I figured, if it opened early, what’s the harm?

Car still overheats, but just like it did in rush hour traffic, near H, not on. I didn’t push it to peg it. I just don’t think it should overheat that quickly. We’re talking 2-3 minutes. Car was burped, and the thermostat was installed with the coil side towards the engine. I am assuming that is correct. Could it’s water pump be broken/seize? Does that happen?

Also:

I unscrewed the jet a quarter (counter clockwise facing bowl) hoping I might get a little more power from it, but I didn’t notice a change other than it was easier to start. Maybe it just really doesn’t like hills. Back to original setting, screwed a quarter the other direction, car stalled on my backing out. Car cools itself back down to middle when parked. I know the car has low compression, but I swear it drove much better from the shop. Certainly didn’t overheat sitting in the driveway for 2-3 minutes.

I also need to stop starting the car in 1st gear. I’m running out of clean pants.

There’s also a strange ticking noise going on when the car is running. My husband assures me that it always did this. My mustang does it too, so I’m assuming “feature.”

 

[trrdster2000]

Umm, can you se the results of over heating? Is water flowing out of the top of the radiator? Into the bottle below???
It could be a bad sending unit or a bad gauge, they are both easy and cheap to buy and install.
You have voltage regulator that gives 10V for the gauges, that may be broken and giving you a high voltage at the back of the gauge, making it read high.
Does it stumble when getting hot, indicating a blow head gasket, lets not go there until the other things are checked.

 

[UmmYeahOk]

Coolant does NOT flow out of the radiator into the bottle. It does however leak a little at the thermostat seal, which means, I clearly did not seal it properly enough, even though I did tighten the crap out of it. The temp climbs high so quickly that it pegs H this time.

Car does not stumble at all, seems to run normal despite temperature. I don’t suspect blown head gasket, as coolant doesn’t appear to have oil in it, and dipstick doesn’t show whitish oil, however it remains mostly clear, like a recent oil change, however the last oil change was almost a decade ago despite maybe a maximum of 300 miles on it. Could old oil cause over heating?

I STILL haven’t figured out how to work a voltmeter. Both temp and fuel gauges stopped working at some point during our post-shop tear down. A completely new wiring harness was purchased in hopes to fix this issue (as well as a few others). My speedometer was removed and “rebuilt” by my husband. Gauge works during testing, but I believe the issue is in the transmission. Since this was touched, and that seems to be where the voltage regulator is, I replaced the rusty mechanism with a new one from spitbits. The fuel gauge now works (I guess). The most I’ve ever gotten from it was 1/4. During previous attempts at correcting my float valve carb issue, I noticed that it took quite a while for the car to heat up. So this indicates that the car got warm from idling lengthy amounts of time, but this overheating thing is a new problem.

So you’re thinking that maybe the temperature sending unit sensor is bad? 10yo/300 miles, could be still though. It climbs fast, but not nearly as fast as when I placed the gauges ground wire directly on the hot spade.

Current jet settings however, I noticed that to start the car, choke must be closed for it to even start (80-90 degrees), then, and only then, can you open up the choke a little to lower RPMs. Starting with choke at full open or half will result in the car not firing up.

 

[trrdster2000]

You have the indication of bad readings on the gauge. The sending unit at the front of the thermostat housing is really a grounding unit, it varies ground contact, The light green wire on the gauge is coming from the regulator, it will not read a constant 10 volts but will go all over the place between a couple of different voltages but will average 10. If you don't know how to use one of the meters, we need to learn that little problem solver right away.
Harbor Freight gives them away on a lot of purchases and if you get one, it would take about 10 minutes to teach you how to use the volt part and the OHM part. Lots of Utube on it.

 

[dklawson]

In addition to what Wayne is suggesting I have a couple of observations.

You mentioned a t-stat housing leak. You have to fix that.

You mentioned a new voltage stabilizer and new gauge wiring. The metal voltage stabilizer housing MUST have a ground connection via its mounting foot. Without the mounting foot providing a ground connection the stabilizer does not switch on and off to deliver the average 10V. Instead, when the engine is running it will pass full system voltage which is closer to 14V. Therefore, your gauge may read as much as 40% high. Make sure the metal can of the stabilizer is connected to ground. Also, if you bought a new electromechanical stabilizer (not a modern solid state one) you should pay attention to which side is marked "top" and mount it accordingly.

If you don't have an infrared thermometer, this is an excuse to buy one. Harbor Freight, eBay, and Amazon are obvious places to buy one. Clean the t-stat housing and spray paint a quarter size area on its top satin black. Start the engine and watch the dash gauge. When you see the temperature start to rise, aim the infrared thermometer at the satin black target on the t-stat housing. Compare the t-stat housing temperature to the dash gauge. You can also aim the thermometer at the top of the radiator and compare it as well. Let us know how the infrared compares to the dash gauge.

Before this thread gets out of hand, you may want to start separate threads for the various problems.

 

[UmmYeahOk]

I found a YouTube video which claimed that I could buy a multimeter at a place called “Radio Shack” or a “Sears.” I am beginning to wonder just how old Youtube is. Anyway, when I said that I did not know how to work a voltmeter, what I really meant was that I can get all sorts of numbers but have no idea what they mean.

My gaigd gets 56.5 ohms off and 66 on. The DC is;

1.5 Cold
3.5 1/4
4.5 1/2
5.5 3/4
6.6 Hot

the regulator gets 1.26 DC on or running, and 32.35 ohms on, but is all over the place when off.

As for the regulator mounting/grounding, here’s a pic of how I have it. Top is pointing down, because logic. This is the exact one I bought:
https://www.spitbits.com/store/6-VOLTAGE-STABILIZER-GT6-P2145.aspx
it has to be mounted downward because of how it screws in, and where that little “foot” is. Having “top” actually be top, I can’t screw it in and the bracket would be too long to fit in the “foot.” Was I sold the wrong part?
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[dklawson]

The stabilizer you bought is not necessarily right or wrong. Unfortunately it is nearly impossible to read the output from one with a digital meter to determine if it is working. Regardless, it looks like your stabilizer is on the speedometer. Make sure the speedometer has a good ground. Usually a black wire with ring terminals on each end is used. One ring terminal goes on a gauge mounting stud under the thumb nut and the other is screwed to the chassis somewhere behind the dash.

Don't worry about making resistance measurements of the sender. I doubt anyone has a list of what the values should be to help determine if something is wrong. However, I would love for someone to prove me wrong and post those values.

You said this car has a new wiring harness. Is it a British wiring harness or did you and your husband decide on an aftermarket harness like those sold by painless wiring?

As a footnote, if you do determine that this voltage stabilizer is at fault, I suggest buying a solid state one. Spitbits does not offer them but others like BP Northwest do. The solid state stabilizers deliver a constant 10V when powered on and they do not have to be oriented with "TOP" up. They also have become less expensive than the electromechanical ones.

 

[UmmYeahOk]

I’ve attached a pic of the voltage stabilizer I got from SpitBits. Sure looks like a solid state to me. I attempted to flip it backwards so that “Top” would actually be on top, but broke the grounding bracket weld in the process, so I had to screw it back together with a tiny bolt and nut. Reinstalled it and the exact same result as before. I went to test it with the multimeter and shorted it. Sparks flew, and both gauge needles fell back down.

I installed an old rusty one I had on another speedometer, and it doesn’t seem to go past the middle. It also shows I have less gas than before, which is disappointing because I’m sure there’s at least 3 gallons there for it to be nearing the E.

Back to the original topic: So since it wasn’t overheating, I went up and down our street tweaking the jets up and down and nothing I seemed to do gave it any extra power. I was able to get it to go 53 MPH (in a 50) before my intersection, but it took FOREVER! Pedal to the floor in every gear. Don’t ever ask for it to go up a hill! It will question when tea time is, as if that’s relevant.

UPDATE:

Discovered that I lost my drivers side tail lamp cover, but successfully retrieved it with only minor scratches to the surface. Lucky.

Also discovered where my husband was hiding his infrared thermometer. I shot the car with it at the halfway mark on the temp gauge. The readings, using a 160 degree thermostat are as followed:

Radiator 173
Engine 178
Water Pump 175
Intake Manifold 167
Exhaust Manifold 251

 

[dklawson]

Why did you take the stabilizer apart? To put it back together, place the board in the metal can and use tiny vise grips to squeeze the flanges of the can back into firm contact with the board. I am going to PM you with some volt meter instructions.

You have confirmed the stabilizer is solid state so the "TOP" designation doesn't mean anything nor does it need to apply. What it does say is that with NOTHING connected to the stabilizer's "I" terminal, battery voltage supplied to the "B" terminal, and the case providing a ground path... you should measure 10V DC between the "I" terminal and the car's body.

I missed something. When did you determine the car really wasn't overheating? Did you make temperature readings on the thermostat housing with the engine running?

In my last post I asked if your new harness was a British one or an aftermarket wiring harness like those sold by Painless Wiring. Please let me know what you have.

 

[trrdster2000]

Doug, in her last post, she said the needle was in the middle when she put the old regulator in, so that problem is solved, we hope.
Now the distributor may be the problem. Check the timing, loosen the clamp and turn the distributor anti clock wise a little at the time, when it reaches max RPM go back 100 RPM's, you will now have a high idle, so carb adjustment, sorry.

 

[dklawson]

Thanks Wayne. I missed that closing paragraph about the IR thermometer and normal temps.

 

[UmmYeahOk]

Duplicate. Trying to delete.

 

[UmmYeahOk]

PM received, thanks, and I updated my profile to display my name, as requested.

I forgot to mention where I got my wiring harness from. I got it from here:
http://www.britishwiring.com/Main-Wiring-Harness-Triumph-GT6-Mk-1-p/1808.htm
I figured I would be safer buying one than to make my own and risk getting something wrong.

The distributor points and timing was set by the shop, and the car ran just fine as is, until I started trying to fix my flooding carb issue. I noticed in my owners manual that it suggests you run 100 octane with the timing at 13 degrees DTC. I had previously filled up with 91, but when the carbs started gushing out fuel, I put whatever I had, which was the cheap stuff my mustang and mower use, 87. I have located an out of the way, yet somewhat close, station that sells 92 octane with ZERO ethanol. I had planned on getting some when I knew if my fuel gauge worked. Could 87 w/ 15% ethanol be a significant contributor to my issue?

 

[dklawson]

I suggested at one point you may want to run multiple threads on the forum to keep the subjects apart. This thread is now discussing engine temperature, wiring, ignition settings, and carb adjustments. Pretty soon it will be hard to remember what has been said in previous posts.

Since you bought a harness from Britishwiring the normal color codes and such will apply in future discussions.

The fuel recommendation in the manual is good but it is not going to be the reason the engine is hard to start or isn't developing power. All gasoline has about the same amount of energy per gallon. Higher octane fuels just burn smoother with less chance of knock or detonation. Because premium burns smoother, cars that run premium gas can have their ignition timing advanced a bit and that is what can allow an engine set up for high-octane gas to develop a bit more power. It's not the gas itself, it is the ability to advance the ignition timing.

If the shop did not put a bit of thin grease on the heel block of the points (tha part that rubs against the square cam under the rotor) there is a good chance that the points have "closed up" even after only a very short time running. That will make the engine hard to start and may cause it to shut down after a brief period of running. I assume you have set points before. If you have not, I suggest going to YouTube and searching for videos on how that is done. Seeing the process will be more helpful than my long winded text explanations.

Likewise, have you set static timing? If not, I am sure there will be videos on YouTube. I also have a PDF on the subject. You can find the PDF by visiting the link below and searching for the phrase "statictiming". For now I suggest you totally ignore the 13 degrees BTDC you found in the manual. Set the static timing for about 8 degrees BTDC. That will make it easier to start the engine and it will develop adequate power. You can advance or retard the timing from there once you have the engine more or less tuned in.
https://sites.google.com/site/purlawson/home/files

Lastly, I don't want to reopen the subject of what the shop did or didn't do. However, as you work through these problems you must act as if the shop did nothing and you have to do everything. My point is, you need to start by setting the valve clearances with the engine cold. Then check and set the points gap and static ignition timing. Only then should you work with the carburetors. Everything else has to be working right before you work on the mixture.

 

[STeve 1958]

If you ran some gas through that had ethanol, you could have clogged up your jets or the fuel filter. The Ethanol acts like a detergent and dissolves the crud in your gas tank. This would definitely result in a lac of power.
When I did this with my GT6+ in 1978 I had to stop every mile and blow out the fuel filter until I got home. Check the filter for stuff that looks like varnish.

 

[UmmYeahOk]

I suggested at one point you may want to run multiple threads on the forum to keep the subjects apart. This thread is now discussing engine temperature, wiring, ignition settings, and carb adjustments. Pretty soon it will be hard to remember what has been said in previous posts.

This thread’s topic is about the cars lack of power, and surging when I get in. The cause of the surging had yet to be addressed, but almost everything discussed is about my lack of power. An overheated engine, in theory, could lack power. This issue was also brought up because in addition to potentially being the/a source of the problem I also no longer could troubleshoot the carbs until this issue was solved, and people following needed to know this. It would seem odd to make a separate thread by that point.

The wiring harness was just a random question, which was repeated since I failed to answer the first time. It also made more sense here to simply answer it rather than start a new thread. After all, the wiring not only could have been the cause of a false temp gauge reading, but could also be a grounding issue effecting the distributor and such, which itself was recently brought up as being a potential source of the lack of power.

Ignition settings - again, trying to solve a loss of power, so any random thing, including the type of fuel used is relevant. Did I remember to preform a sacrifice in the cars honor before attempting to start the ignition? All relevant. It just seems to me that a two page thread makes more sense here than say, 5 separate ones

Now then, with that said, you will all be relieved to know that...
PROBLEMS FIXED!
...at least for the time being.

I mentioned my test drive to my husband last night, and he said that it sounds almost as if the car was running on just one carburetor. Today I unscrewed the problem carb. The one that previously would flood, and that I had to customize a newer float. Well, the bowl didn’t have much fuel in it. The float also did not meet that recommended 17mm raise limit. ...and the float valve was stuck YET AGAIN! So I made some adjustments, cleaned the float valve (again) then test drove it. It had just rained, running out of daylight, and my tail light cover was still not installed, so I only drove it up and down our street on the hill, and it preformed beautifully. It shifted smoothly and did not question me at all whenever I politely asked it to accelerate for me. I will have to test drive it for real tomorrow and see if I can start it back up again after being driven (simulating my trip to the drive in restaurant, where the engine flooded).

The surging issue I think solved itself. Simple logic says that getting in causes the car to lower/dip briefly. This sudden change in elevation causes additional fuel to go into the starving carb, increasing the RPMs.

-Edit-

after uploading the pictures, I noticed that you can’t tell anything from them. The bowl actually isn’t empty. It is about a centimeter or less deep with fuel, and the measuring caliper is set at 17mm