Loss of Power Under Load

Paul in Washington

Paul in Washington

New Member
1969 TC 2000 runs fine about town but distinct loss of power going up hills. Changed points, plugs and dist. cap, which looked fine, and after-market electric fuel pump. Car ran fine for years. This problem is new. Suggestions appreciated. Thanks!
 
My 2000 TC was lacking low end torque. I would have to change down a gear earlier than I used to. The solution was to adjust the valve timing with the vernier adjustment. This adjustment is easy and is described here (as a stick thread). I would check valve clearances while you have the cover off, and adjust those if needed as well.

My other suggestion would be to disconnect the fuel line from the carbs, and briefly, and not in the presence of smokers, turn on you ignition and make sure you have a good fuel flow out of the line. It should squirt vigorously. If your fuel lines are clogged with rust and debris then you will have fuel flow problems even with a new pump. If the lines are clogged with crap, then you should also inspect the fuel tank, it may be rusty.

Also check under the car and see if there are any inline fuel filters installed that need replacing. There might be one from a previous owner that you do not know about.

My 2000 automatic likes to run best on the reserve fuel line. There seems to be some constriction in the main line. Have you tried both fuel lines. Also is the main reserve fuel valve opening and closing all the way?

James.
 
sdibbers changed condenser. PeterZRH, not sure how to check vacuum. Soffolkpete, not sure how to check that either.

I have thought about it and am convinced that the problem is fuel starvation because after sitting at a stop light and accelerating hard, the engine works perfectly. On a steep incline at power the engine gets weaker as it goes then returns to normal on the flat.

I saw another thread about gunk in the fuel tank or fuel lines.
j_radcliffe said:
My 2000 TC was lacking low end torque. I would have to change down a gear earlier than I used to. The solution was to adjust the valve timing with the vernier adjustment. This adjustment is easy and is described here (as a stick thread). I would check valve clearances while you have the cover off, and adjust those if needed as well.

My other suggestion would be to disconnect the fuel line from the carbs, and briefly, and not in the presence of smokers, turn on you ignition and make sure you have a good fuel flow out of the line. It should squirt vigorously. If your fuel lines are clogged with rust and debris then you will have fuel flow problems even with a new pump. If the lines are clogged with crap, then you should also inspect the fuel tank, it may be rusty.

Also check under the car and see if there are any inline fuel filters installed that need replacing. There might be one from a previous owner that you do not know about.

My 2000 automatic likes to run best on the reserve fuel line. There seems to be some constriction in the main line. Have you tried both fuel lines. Also is the main reserve fuel valve opening and closing all the way?

James.
Click to expand...

Thanks James will follow up.
 
My experience of the effects of dirt and rust in the fuel is a little different to that. It would run fine until I wellied it up a hill then it would miss a few times and cut out completely. Under normal running, enough fuel was getting through to keep the float chambers of the carbs topped up. But under heavy load, their levels would drop as more fuel was being drawn than could be replenished. It could run normally like this until they emptied completely, then wouldn't run at all. A general drop in power was not one of the symptoms.
There was also a heavy build up of crud visible in the glass dome of the fuel pump. If yours looks clean, I doubt if this is your problem.
 
Thanks Willy, that sounds a lot like mine, except it doesn't cut out completely. Unfortunately, a prior owner swapped out the mechanical fuel pump with the glass dome with an after-market electric version. But I am going to follow-up on the fuel and lines shortly.
 
So today we disconnected the fuel line at both ends, tested the electric fuel pump for volume and pressure, and everything was fine! There was no gunk seen anywhere, the fuel line was clear and clean. We pumped about a quart of gas into a jar and it was perfectly clear. My shade tree mechanic, who is on probation, said he wished his urine sample looked that good. The pump was putting out plenty of volume and the pressure was 5 lbs. So there seems to be fuel starvation, but doesn't appear to be the tank, line or pump. So I'm back to square one. Any suggestions appreciated.
 
SUCCESS! (w/ small caveat)(tachometer) Is there a nicer feelings in the world than when your Rover is on the blink for a long time and then suddenly it's working great? Yes, there is, but you need another person for that :) Anyway, as you recall, I was sure that I had a fuel starvation issue cause this P6 would run perfectly until you went up a steep hill, when it would lose power. Once you crested the hill and started down it was fine. So I trouble shooted the fuel line, pump, tank, etc with no luck. Then from on this site I heard about electronic points, ordered the Pertronix 142A LU-142A IGNITOR LUCAS 25D4 DIST, 4 CYL and their new coil and viola! it worked. The old power is fully back and thanks to all who made suggestions. I don't know if it was the coil or the points, since I changed them both. The guy who sold the points however really recommended the new coil too. The old coil was itself a replacement part made in Mexico, so this is at least the second replacement. BTW, my mechanic here in the states told me that coils rarely go bad and that if they do you will know it cause the car won't start, but now I wonder if that's the case. I thought about testing whether it is the coil or the points by re-replacing one then the other, but when your Rover is running just right I thought I'll just leave everything be and live with the mystery....

Oh, everything is great but the tach stopped working when I put in the electronic points...
 
Paul in Washington said:
Oh, everything is great but the tach stopped working when I put in the electronic points...
Click to expand...

Could you describe how you have wired the electronic ignition in?
The original set up for the points, has the the line between the distributor and the coil negative pass through the tachometer, this is how the RVI tachometer senses the engine speed. Try to wire the new module also in this way, and perhaps you will be lucky. My lumenition magnetronic module has no problem to cooperate with the tachometer in this way, but apparently it doesn't work like this for all electronic ignition modules.
If it doesn't work, then your only solution is either to replace your tachometer with an RVC, or convert your existing to RVC (i think codekiddie from this forum has done it).
 
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Im experiencing the very same issue right now. The guy who has been servicing my car recently wants to get the head off and look at the valves. He has also suggested changing the carbs for the bigger ones from the 2000TC (mines is a 2200TC).
However, the idea that it might be fuel related is interesting as I had significant issues with rotten/gummy fuel being dragged through the carbs around 18 months ago. I thought it had been rectified (as much as is possible without cleaning out the fuel tank) but I still get the odd issue with the carbs due to grit/dirt in the jets. Maybe there is still an bigger issue here which is causing the drop in power under load?
 
craig r said:
The guy who has been servicing my car recently wants to get the head off and look at the valves.
Click to expand...

Has he done a compression check? Has he checked the valve clearances?


craig r said:
He has also suggested changing the carbs for the bigger ones from the 2000TC (mines is a 2200TC).
Click to expand...

That's a retrograde step. Just because the early carbs are bigger, doesn't mean they're better. Search the forum to find all the people that have changed from the early carbs to the later 2200TC ones on their 2000TC engines.
 
harveyp6 said:
Has he done a compression check? Has he checked the valve clearances?
Click to expand...

+1 on checking the valve clearances. Its very easy to check on our engines, but a right bugger to rectify. Having said that, when they are right it makes a huge difference to performance, smoothness and fuel consumption. Not to mention the fact that if valve clearances close up too much you risk burning an exhaust valve.
 
Yes I second checking the valve clearances. When you've got them set up right you'll certainly notice the difference. Make sure you check them when the engine is stone cold.
 
He hasnt checked any of that yet. He did a huge raft of work earlier in the summer but just couldnt get to that within the time/budget contraints. But he identified the lack of power and we discussed the next steps in terms of work required. He wants to get the cylinder head off and check everything. I would consider the carb change more of an enhancement and if I did decide to go ahead with it I would only do it after the power issue had been resolved.
 
craig r said:
He hasnt checked any of that yet. He did a huge raft of work earlier in the summer but just couldnt get to that within the time/budget contraints. But he identified the lack of power and we discussed the next steps in terms of work required. He wants to get the cylinder head off and check everything. I would consider the carb change more of an enhancement and if I did decide to go ahead with it I would only do it after the power issue had been resolved.
Click to expand...
The carb change would actually be a backwards step. The 2" carbs are way too much for even the 2200 it tends to push the sweet spot of the engine up the rev range. In fact, I rebuilt my 2000TC engine as a 2200TC a while ago and ran with the HS8's at first. Counter intuitively I found that I was running lean most of the time as I didn't have enough manifold vacuum to lift the carb pistons enough. I switched to HIF6's last year, and after some unrelated problems found I was getting much more responsiveness and power with the HIF6's.
 
craig r said:
He hasnt checked any of that yet.
Click to expand...

Why not?


craig r said:
He wants to get the cylinder head off and check everything.
Click to expand...

Words fail me. Perhaps he's never done one, so would like to be able to add it to his CV once he's practiced on yours. I'd want a reason to remove a head, rather than a random guess just to have a look, but hey-ho, you're paying the bills.

craig r said:
I would consider the carb change more of an enhancement and if I did decide to go ahead with it I would only do it after the power issue had been resolved.
Click to expand...

Just to get this straight, you would consider that fitting worse carbs would be an enhancement?
 
Whoah hang on. He's very experienced in P6's having worked on them when they were used by the Police. Perhaps im not explaining what he wants to do properly.
I explained why he hasnt done it yet. There was a raft of other critical work that needed done and I simply didnt have the budget for him to carry on and look at other issues, But they were identified and Im looking at when I can get it done.
And when I say 'enhancement' I mean work thats not critical. It would be a nice to have rather than a must have. But if the advice is that its not benificial, then it wont be getting done.
 
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