lack of power in 4th gear

[taj34]

1986 mini
998 engine
Stage one kit

I had the engine in my mini replaced last month. Before it was replaced I was able to drive at 60mph all day and push to 70-80 mph when I to needed to for passing. Now my mini tops out at 50mph and has problems going up hills. It also very annoying to be driving and have the mini shift to 4th lose power and then downshift to 3rd and then up shift to 4th and so and so forth.

So far what I have done.

Spark plugs are new
Adjust the mixture, there was a power increase but I had to move the nut all the way down and pull the choke all the way out for it.
Checked the exhaust and there doesn't seem to be a any leaks
Oil changed
Checked the vacuum advance cable and it seems fine
Added damper oil

I figure the next thing will be to move the distributor, but what other things should I check for?

 

[wimfournier]

The words that you use do they mean that someone else placed the 'new' engine in your car? And you payed money for that? Well let him (her) sort the problem.
Where did the 'new' engine come from? Was it garanteed as 'good'. Or 'give it a try'?
Came it with a automatic gearbox or is the original aggregate splitted to build the new engine on the old box.

Tell us the story so that we can think it out what went wrong.
And where do you live. maybe one of us is in your neighboarhood.

[notamini]

I just hope the engine was an auto block!
I have to agree. The engine supplier should be working it out for you. Was the carburetor part of the deal or did you supply and install it?
It would help if you could expand on the term replaced engine. All, some or no ancillaries?

[taj34]

The engine came form another automatic mini. The engine it self had a rebuilt transmission and block and was guarantee to be a good engine. When they did the swap they used the carburetor, coil, distributor, starter and so on from my old engine on the new one.

I am live in Pirmasens, Germany.

[limby2000]

Does it sound sluggish ,or is she screaming, perhaps the kickdown rod is not adjusted correctly, since the carb was removed its a possibility. Tbh it sounds like the powers down.

[taj34]

Gears 1,2,and 3 sound fine but 4th gear sounds louder then it should be. At 55mph 4th gear sounds as though I am going 70mph.

[wimfournier]

So, when the box is changing from 3rd to 4th gear the rpm of the engine is increasing when you push the throttle but the car is not gaining more speed.
If so, it could be that by re arranging the gear box the brake band of the highest gear is not set correctly and slipping.

I looked up where you live, I live near Amsterdam. A bit far to come to rescue you.
But, the fellers that did the engine swap for you or the guys that did the rebuild of the box and engine should be able to help you with this easily: Taake the lid off the front of the box and adjust the the nut that tightens the brake band. New gasket, job done.

[firept]

Ok before you go any further you need to ask the question 'What has changed?' and 'What was worked on last?' that will answer what is wrong.

So if you have just had the engine replaced then either there is an engine problem or its connection / drive to the gearbox.

If you have had BOTH the engine and gearbox changed then its more likly be the gearbox related, of course it could be the torque converter.

It could also (and I will need someone on here to correct me) but there were I think 2 different ratio's of final drive has that been checked? you may need to get the part numbers off of the old and replacement gearbox and do some 'google' research. 

You say "

So far what I have done.



Spark plugs are new

Adjust the mixture, there was a power increase but I had to move the nut all the way down and pull the choke all the way out for it. "

This would point to an air leak on the inlet as you are enriching the mixture i,e you are needing more fuel for the amount of air  entering the engine I would look all around the manifold first to see what is going on,  can you access a Co meter or exhaust gas meter?  A local test station should have one just ask them to measure the exhaust gasses  this will be a good guide. 
When the carburetor was taken off of the car and  fitted back was it taken apart and cleaned as you could have sludge and muck blocking the small feed pipe to the jet assembly.
Check that the vacuum connection from the inlet manifold to the brake servo is good and no leaks.
Make sure the ignition timing is correct and that the vacuum advance does still work.

In any case its back to the installer / fitter as its for them to sort out. 
You need to ask yourself if it was just your original engine that was faulty or worn out why not just get the offending part rebuilt?
It's often better to fix the devil you know.

Best of luck