Power loss

[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:Attachment 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-E7D...JU5RHt&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-E7D...JU5RHt&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.



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