Power loss

[slowmo]

I have suffered a recent loss of power, which given the meager amount to begin with, is catastrophic. Ok. I’m over stating it a bit. (Background info: I work at an altitude of 4500 ft, but I live at 6000 ft) Going up my mountain highway after work, I could previously hold 4^th gear to a particular sign next to the highway. Now I have to downshift quite a bit earlier. On steeper parts in 3^rd gear I could normally hold to 3500 rpm the entire way. Now it bogs down to <3000 rpm in some of the steeper areas.

I installed a new electrical fuel pump which eliminated the vapor lock issues I had over the summer. I installed a new carb kit. I am getting horrendously terrible gas mileage. The plugs always look just slightly rich. New spark plugs/wires/distributor cap/rotor/points. Here is my full British car tune up procedure (sort of like a full Scottish breakfast…without the blood pudding). Please let me know what I am missing.

1. Re-torque cylinder head bolts
2. Adjust valves
3. IRAN (inspect and replace as necessary) plugs, clean, re-gap and reinstall.
4. IRAN distributor cap, points, rotor, condenser
5. Set point gap, start truck and warm to normal running temperature, measure dwell angle, readjust points as necessary
6. Set up timing light. Remove vacuum advance line at carb. Check timing holding thumb over vacuum fitting on carb. Adjust at distributor to spec
7. With tach/dwell meter still attached, adjust idle to 1000rpm (Weber 34ICH). Adjust mixture for best running.
8. Recheck dwell angle and timing.
9. Button it up, test drive and note that I have still lost power.


Other ideas?

[LaneRover]

If it seems to be running rich have you tried going down a size with your carburetor jet?

Is the air intake/air filter blocked off at all?

[slowmo]

Since I am seeing only slightly rich (meaning just a little black but no carbon build up) I feel the mixture is on the correct side of wrong. I would rather be a little rich than too lean and end burning up valves or the top of a piston.

I haven't reached an understanding of the really bad fuel mileage...I mean like really bad...the fact that the plugs look "ok" and I have lost significant power. It could be air intake. That's a good thought. I'll look in to it.

I also just noticed I haven't replaced the condenser and the coil. There is a chance one of those is weak, but that is not what I have usually found. Nevertheless, ordered those. It's weird. Generally I figure these things out, but this dang Rover has its' own mojo. Weird mojo. I think that some of the robust nature of the trucks somehow masks some of the finer tuning issues that I get with say my TR3. I can get that sucker running like a striped a$$ ape every time. MGB...no prob. MG Midget...I should hire my services. Rover...still learning and I don't get why it is differrent...but it is.

[SafeAirOne]

Any chance you have a sticking brake? Are any of the wheels hot after one of these uphill drives?

[slowmo]

Good one, Mark! I certainly didn't think of that one. I'll check.

[TeriAnn]

It's weird. Generally I figure these things out, but this dang Rover has its' own mojo. Weird mojo. I think that some of the robust nature of the trucks somehow masks some of the finer tuning issues that I get with say my TR3. I can get that sucker running like a striped a$$ ape every time. MGB...no prob. MG Midget...I should hire my services. Rover...still learning and I don't get why it is differrent...but it is.

The TR and LR use the same technology level and except for the down draft carb on the LR the engines tune the same. As an aside, I one offered up a TR3 intake manifold to a Series head and discovered that the ports lined up as did a couple of the bolt holes. I decided that a good machinist could make a TR3 intake match up to the Series head. The only problem would be the LHD steering box would be in the way of the rear SU.

The electrical systems, year for year used the same tech and often the same parts. The big differences are the rest of the drive train and steering. Well, the brakes are more primitive on the LR than on the disc brake TRs. Think of the LR as a big clumsy TR and you should be fine. Except for the carbs everything you know about the TR helps with the LR. I've been dealing with the two of them side by side since my TR3 joined my LR in 1986. It is the same basic tech, just the TR is more refined and the LR has a whole lot more drive train bits.

[LaneRover]

Very good thought on the brakes. I have to watch my parking brake on bumps because it will 'ratchet' on bit by bit.

[SafeAirOne]

About 10 years ago I became unable to break the 50-mile-per-hour-barrier on my morning commute. It took me a few days to figure out that my brakes started out the commute just fine, but as the number of brake pedal applications increased, so did the amount of brake dragging.

[slowmo]

Well it's not the brakes. That would have been such an easy fix.

One thing really puzzles me which I have never seen on my current and past fleet of British sports cars. If I time the truck to be spot on and then advance the timing by ear to achieve the smoothest idle, the timing mark is at least an inch above the pointer. I'm an engineer damn it, and stuff should be spot on (throws hands up in disgust).

Everything points me to the crappy carb mated with a more than crappy intake manifold. It's as if they wanted the trucks to run...well...crappy. I would love these but I doubt they would fit:

[lumpydog]

the timing mark is at least an inch above the pointer.

That sounds about right. Likely 6 degrees BTDC or so. Fuel has changed since the time the specs were published (and when that pointer was fixed in place). Today's fuel burns differently (mostly slower), which requires an earlier spark. Wouldn't think twice about it unless your engine knocks under load or up hill - then you may want to retard the spark a bit.

[christoph]

Possibly a quick compression check to confirm that the valves are doing what they're supposed to be doing? Could the high fuel consumption be caused by leaking fuel out on the road through a loose connection while you're driving?

Christoph

[slowmo]

Compression check. Good idea. I checked it when I bought the truck last December, but not since.

I have checked for fuel leaks with none found.

I set timing by ear, but then it snowed so I haven't had a chance to try it out. Maybe tomorrow.

[westcoastkevin]

Do you buy your fuel at the same place? Have they switched to a winter blend from the refinery?

[slowmo]

Another good thought. I think I noticed the loss around Oct. That is about when they start increasing the ethanol. Hmmm.

On the timing issue, I had set the timing to be spot and enjoyed months of the "thunderous" Rover Power before losing it. Advancing it may help, but does not explain the loss. I am still leaning towards the fuel and the timing of increased ethanol here in Reno seems a coincidence. I hate coincidences. Anyone else see such a thing?

[TeriAnn]

Well it's not the brakes. That would have been such an easy fix.

One thing really puzzles me which I have never seen on my current and past fleet of British sports cars. If I time the truck to be spot on and then advance the timing by ear to achieve the smoothest idle, the timing mark is at least an inch above the pointer. I'm an engineer damn it, and stuff should be spot on (throws hands up in disgust).

If the engine is tired the timing chain is likely stretched. Also the bushings on the distributor might be worn. Check for distributor shaft side to side wobble.

Everything points me to the crappy carb mated with a more than crappy intake manifold. It's as if they wanted the trucks to run...well...crappy. I would love these but I doubt they would fit:[ATTACH=CONFIG]11120[/ATTACH]

Looks like TWM intakes. I have a pair of those and a pair of 45DCOEs on my TR. I think if you have a RHD LR you might be able to modify the intakes to fit the LR head. The ports line up.