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 4th gear to a particular sign next to the highway. Now I have to downshift quite a bit earlier. On steeper parts in 3rd 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:11120

[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:11120

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.

[o2batsea]

I installed a new carb kit. I am getting horrendously terrible gas mileage. The plugs always look just slightly rich I assume the plugs are black-ish?

Problem solved I'd say. You are likely overfueling it. Your timing is probably just fine. What jets do you have in there? Remember there are fewer oxygen molecules up there, so you need to go smaller jets than at sea level.
Another reason to seriously consider EFI conversion...it would eliminate that sorta stuff.
All you need for the conversion is this:
http://www.ebay.com/itm/OEM-Ford-E7DE-JA-2-3L-TBI-Throttle-Body-W-Injector-W-IACV-86-88-Taurus-/331483728740?hash=item4d2df84b64:g:M-oAAOSwZjJU5RHt&vxp=mtr

Plus the control box and wiring. That is readily available from any 2.3 powered Ford from the mid 80's-90's. Millions of 'em out there. Parts easy to get and it's more or less bolt on, hook up and go.

[slowmo]

Welp. Just an update: The timing tuned by ear (which resulted in the timing mark being about 1" above the pointer) was no good. I almost had to downshift into 2nd going up the mountain. I assume with the vacuum advance it was too advanced. Back to timing to the pointer.

This weekend: on goes the new coil and condenser, compression test, spark plug analysis for mixture, and check manifolds for leaks. Already did new points, rotor and cap. If I still have the power loss, at that point the main suspect will still be the carb, though I put a new kit on it about 4 months ago.

I will report the results.

[slowmo]

I assume the plugs are black-ish?

Problem solved I'd say. You are likely overfueling it. Your timing is probably just fine. What jets do you have in there? Remember there are fewer oxygen molecules up there, so you need to go smaller jets than at sea level.
Another reason to seriously consider EFI conversion...it would eliminate that sorta stuff.
All you need for the conversion is this:
http://www.ebay.com/itm/OEM-Ford-E7DE-JA-2-3L-TBI-Throttle-Body-W-Injector-W-IACV-86-88-Taurus-/331483728740?hash=item4d2df84b64:g:M-oAAOSwZjJU5RHt&vxp=mtr

Plus the control box and wiring. That is readily available from any 2.3 powered Ford from the mid 80's-90's. Millions of 'em out there. Parts easy to get and it's more or less bolt on, hook up and go.

Tried lean as well. The plugs looked perfect but the power loss was still there. Then I tried a little rich (the blackish plugs) and no change. I don't know what jets I have, and perhaps that could be optimized. However, they are doubtfully part of what has changed resulting in my power loss.

The EFI is interesting. Are you running that?

[o2batsea]

No, I have Tdi power in my 109. However if I had a gas 4 banger I would definitely do fuel injection. TeriAnn did her Ford many years ago after I bugged her enough and has never regretted it. I think you too will see much trouble free mileage with the carb in the trash where it belongs! I converted a pair of marine gas engines to Megasquirt several years ago, and they ran great. I still have a bunch of Megasquirt stuff laying around that is not being used now that I'm diesel (and that boat is long gone)
The Ford system is virtually plug and play. The only thing you may have to add are a couple sensors like coolant temp, air temp, stuff like that. All those are cheap and easily incorporated into the engine without a lot of hassle. The ECU can live in the engine compartment and only needs keyed power. Oh yeah one other thing you'll have to do is plumb a fuel return line to the tank and maybe add in an electric fuel pump. Also the ECU gets its timing signal from the diz. You will want to change that to the coil instead but that should be the only mod (unless you decide to use an electronic distributor too in which case you can attach the ECU timing wire to the diz) The Ford diz uses what they call TFI which has an optical pickup inside and a TFI module which amplifies the extremely weak optical signal into a robust signal that fires the coil.

So, what you get with EFI is constant fuel metering at the ideal 14:1 air to fuel mixture, easy starting in all temperature conditions, possibly a little better fuel economy and no worry about a flooded carb when you are dangling at a 30 degree angle with a boulder on one side and mud looming up at your driver side window. Oh wait, you're out west where there isn't any mud...

[ja_parker11]

Slowmo,

What is the spec of the new electric fuel pump? Was it intended for fuel injection, 35 psi? May need a pressure regulator to get it back to <15 psi for carbs.

That may explain the fuel economy, doesn't explain the power loss that caused the pump installation.

Is your Rover pre no-lead era? Many years ago lost exhaust valves on a first generation no lead that did not have modified valve train. Problem came when vehicle was taken from sea level to our elevation. It was two years later, that Toyota acknowledged the problem, 1974 model year. Your compression test will answer this one.

Absent this, stop off at the airport and pick up a half tank of 101 LL.

Good Luck from the other side of the basin.



Sent from my HTC6500LVW using Tapatalk

[slowmo]

Alrighty then. It has to be the carb. Valve clearance checked, compression checked, plugs clean and gapped ,new dist cap, rotor, points, condensor, new coil, electric fuel pump (4psi), and still slower than a 90 year old on an electric cart at Walmart.

I put a new kit on the Weber 34 ICH about 3 months ago or so and it ran "great" after that. I'll order another kit and see if something has gone bogusly wrong in the carb...gasket or something. Since the plugs look OK I know it is not running extremely rich and it is not leaking fuel so the terrible gas mileage has yet to be explained.

Grrr.

[mearstrae]

What can kill performance when everything seems OK. Poor manifold vacuum from a timing issue, or a vacuum leak.

'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III Hybrid 109
'70 Rover 3500S

[cedryck]

My dad used to diagnose manifold leaks and gasket leaks using the following method. Us LP gas with a tip and let it flow around the area of question. OBVIOUSLY NOT IGNITED!! Do not light the tip, just let if flow and if you find a spot that is Inhaling the gas, your engine will run better, I watched him do this with cars, and a snow blower, and it worked great. Just be careful. cheers,

[slowmo]

My dad used to diagnose manifold leaks and gasket leaks using the following method. Us LP gas with a tip and let it flow around the area of question. OBVIOUSLY NOT IGNITED!! Do not light the tip, just let if flow and if you find a spot that is Inhaling the gas, your engine will run better, I watched him do this with cars, and a snow blower, and it worked great. Just be careful. cheers,

This is a GREAT idea! I love it when I learn a new trick. So I get my little propane torch and run it all around the intake manifold at the head. Nothing. I didn't expect anything because I had used my little rubber hose to listen all around both manifolds at the head and the exhaust at the clamp and heard nothing suspicious. Hmm.

I run my little torch around base of the carb and wait a second...did I just hear a change? Further testing and "hello" you little fupping induction leak on the back side of the carb. Tighten up the bolts (they weren't very loose at all but did take on more torque) and bingo. Torch test now shows no improvement.

Is this the cause of the loss of power? Will Slowmo find that he can hold 4th gear to his marker sign? Stay tuned for our next episode of "Slowmo gripes and complains because his slow truck is going slower." Same Bat-time. Same Bat-channel.

[cedryck]

That is great!! Glad to hear it worked. I have noticed that my base gasket at the carb. Looks suspect, so I might fit a new one.
I am still chasing that runs great, runs poor ghost on my engine, but have purchased a new timing light, and will start there.

[slowmo]

Hate to leave threads incomplete, so can report that I have regained the lost power. cedryks trick lead to finding an intake leak. I decided to replace the gaskets and while the carb was off, I threw in another kit (Weber 34 ICH). And there it is. Back to thundering up the mountain at 35mph instead of 30mph.

I still get the one finger rover salute on the two lane stretch and I am sure they are honking, but with the ear plugs and all the racket I can't hear them, so it's all good.

[slowmo]

Welp. After many attempts I had accepted the fact that Series Rovers were just complete dogs. Then I lost even more power. Tried all the stuff...again...no improvement. Realized I hadn't checked the compression in a while and cylinder #2 now had 40psi and #3 had zero. Well there's the answer. I pulled the head and found:
116031160411605

Additionally the head was cracked at #3 which let in water or steam vapor which resulted in the weird cracks on the valve.

I had a machine shop fix the head, insert seats on the exhaust valves, press in new guides. I reinstalled everything and the truck runs like a striped a$$ ape. I can climb my mountain highway in 4th gear the whole way! So I will say they aren't dogs...they aren't exactly sporty, but now it drives like it was designed.

Nearest I can tell the head gasket was blown the entire time I owned the truck, but the valve had not yet failed. Compression was fine, but little did I know #2 and #3 were communicated. It took the valve to fail for me to investigate further and finally get to the root cause.

So I can now officially close this chapter...and move on to whatever the next one will be.

[slowmo]

Oh, and here is the repaired head. I hope it lasts a while.
11606

[cedryck]

to reply to the suggestion of a "sticky brake pad",, I did have this problem after I discovered a rear wheel cylinder was not returning properly, one could fry an egg on the rim, dangerously hot!