I have a 1981 Triumph TR8, 24,000 miles. The standard engine was a 215 engine found in Buick Skylarks and many other GM cars. Before I bought it, the previous owner converted it from fuel injected to Holley Carb and Edlebrock intake manifold. It also has a cam of some sort in it.
Last fall I blew a head gasket. Not uncommon with these vehicles. I had a local mechanic install a larger radiator, replace the head gasket, etc. All of that work appeared to be fine.
I got the car back from the mechanic and it runs horribly. Poor idle primarily. Runs a bit rough. The mechanic has looked at it twice and hasn’t solved the problem. Not I’m concerned about taking it back to him.
How would YOU go about finding a mechanic to work on this vehicle?
If i couldn’t do the work myself, I’d look for a classic Range Rover mechanic, the engines are identical.
You probably have the 3.5L version which may have been a later efi version, I’d guess that someone replaced the efi with Stromberg carbs which can be iffy. A common failure point is the rubber diaphragm in the carb splits, check these first, they cause all kinds of performance problems and are cheap and easy to replace.
Poor idling and rough running can be attributed to that problem.
Another prime suspect is an intake manifold leak, it’s a bit of a challenge to fit the gasket correctly and the manifold must be torqued down in the factory sequence, otherwise you will get induction leaks. This is also suspect since you have had recent head work.
~ another point - did your mechanic fit new headbolts when he did the headwork ?
Doh, sorry I did read it but baby brained the Holley / Edelbrock fragment.
Okay with that setup, you need to make sure that the carb jettings are correct. If that engine is the original it’s a 3.5 or 3.9L Rover V8.
It’s similar to the buick engine in that it has 8 cylinders, that’s about all. Rover drastically re-engineered that engine before use. The Buick was cast iron, your engine is alloy.
The intake manifold comments from my earlier response still apply, assuming all is good there and your ignition system is all good, then I’d start to think about the carb jetting.
1 other weak point on the Rover V8 is the distributer, the stock unit is Lucas (need I say more) and the baseplates are rubbish. If this is a Lucas unit, pull the cap off and check that the baseplate has all of the nylon feet intact and moves smoothly, otherwise the baseplate wobbles about.
Personally I’d junk it and replace it with a more upmarket dizzy, the Lucas unit is always troublesome.
Any half-knowledgeable mechanic should be able to work on this; especially since the fuel injection/c omputerized controls have been eliminated.
Since it has been cammed and has an aftermarket carb/intake getting the tweaks out could take some trial and error since the cam profile and carburetion works hand in hand.
I do not know what type of Holley carb you have on this car but that might be the problem right there.
The engine is small displacement and even a small CFM carb may be too much for it.
A 300 cubic inch engine runs just fine on a 400 CFM carb and if someone has used the “bigger is better” approach with the carburetion (many do) they may be killing performance by doing so.
I would verify what Holley carb is on there and if someone has thrown a normal 600 and up CFM carb on there, then it needs to go.
First thing I’d do is put a timing light on it and make sure it’s timed correctly.
Find out what model of carb it is, then head to Holley’s website and download the installation / initial tune manual. It seems like you get mechanics who are maybe a little young but still think they can tune a carb, then they start fiddling with mixture screws, float level, idle speed, and before you know it they have things so screwed up that there’s no escape. I think you need to get things reset back to factory spec and then tune from there.
Is there a British car club of some sort in your area? If so, get in touch with them.
If you are anywhere near Wichita Kansas, contact Joe at H&H Pens. He is a first rate mechanic who has an award winning Triumph very similar to yours. The pens are a sideline. http://www.handhpens.com/