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2002-2005 Range Rover MkIII / L322
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Discussion Starter #1
hi everyone,
I have a land rover 90 fitted with a 4.0 v8 gems engine mated to a 4 speed manual from a classic range rover with classic range rover diffs, on my recent test drive the car would rev very high but feels slow like it is not really pulling/accelerating as i expect, so i removed the transmission to find out the clutch was a bit worn and it was slipping due to oil leaking from the inner transmission seal so i replaced the seal and got a new clutch and a new clutch sleeve cylinder, i reinstalled the transmission being so excited i can finally enjoy my car only to find out that nothing has changed it feels exactly the same, if i put my foot down hard it revs high but the car feels like it is not accelerating, can anyone enlighten me with what might be happening? for a minute i thought i was on low range but i wasnt
 

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1995-2002 Range Rover P38A
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In what condition is the flywheel? Did you just changed the clutch plate, or did you change the lot? Is the slave cylinder of the right type? Did you install the new seal propperly?
 

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2002-2005 Range Rover MkIII / L322
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Discussion Starter #3
the slave cylinder is the correct one, and the flywheel is in good condition as well as the pressure plate, yes the seal is perfect, it is really annoying the car feels so under powered it just revs high but does not move as fast, the engine is running fine no hesitation nothing, so i dont know what might be causing this, could the ecu be the culprit? the engine originally came from an automatic p38 could the becm need setting transmission to manual in the settings?
 

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1995-2002 Range Rover P38A
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the slave cylinder is the correct one, and the flywheel is in good condition as well as the pressure plate, yes the seal is perfect, it is really annoying the car feels so under powered it just revs high but does not move as fast, the engine is running fine no hesitation nothing, so i dont know what might be causing this, could the ecu be the culprit? the engine originally came from an automatic p38 could the becm need setting transmission to manual in the settings?
Did you put a new pressure plate on it?
Did you measure the difference between the old and the new clutch plate?
Are the flywheel and the pressure plate a matching pair?
 

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Sounds like either the gearing is wrong, although if the gearing was too low it would rev and accelerate very quickly, just not have much in the way of top speed or the engine will rev but isn't producing much power. What bits from the GEMS install have you kept? Presumably you have the original ECU, what about things like the knock sensors? Do you still have the OBD connection (I assume you do as you mention BeCM), can you read live data? Things like O2 sensor outputs, ignition timing, short term fuel trims, etc. I wouldn't have thought changing from Auto to Manual in the BeCM would make that much difference but it's worth a try.
 

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2002-2005 Range Rover MkIII / L322
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Discussion Starter #6
stock gems ECU and becm I will upload pictures of the build but you can check it out on my new ig account @r_d.customs i wanna open up a custom build shop next month so this is the project i decided to go with as my opening because it is unique and no one here has ever done it before most people here use the 14cux ecu with 3.9, yes i have obd
as follows:
1. gems 4.0L V8
2. becm and engine ecu
3. ignition switch with key but remote is not working so it is immobilized even with its own key in use
4. steering column with steering complete with wiper and indicator stalks
5. speedometer cluste
6. door outstations for the immobilizer

i have a lot of wires that i will remove once i get the car to function properly, like the rear power window wires, rear dome lights, like all wiring that i will not use for my car, it is a landrover 90 pickup so the cabin is very small not many things from the 4 door p38 i can use, only the front doors stuff i will use, but lights and almost everything else is run from the becm as normal.

02 sensors i did not install but the wiring is all there, i have a straight pipe exhaust system so it is crazy loud!
 

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2002-2005 Range Rover MkIII / L322
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Discussion Starter #7
no the pressure plate is the same because it was ok, only the clutch plate was a little worn, however the new one was a little thicker so the pressure plate was engaged when we tighten it and i had to put washers as spacers to make it work
 

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Discussion Starter #8
i will appreciate any help i can get as i continue with this project, all updates please go to my instagram @r_d.customs
i also have a 5 speed transmission from a classic ranger rover the one with the long shifter and a chain driven transfer box but i hear it is not good is this correct?
 

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1995-2002 Range Rover P38A
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Pretty easy to work out if it is a clutch problem really. Drive in a gear of your choice with the engine doing 1,500 rpm, note the speed. Accelerate to 3,000 rpm, (best to do this up a steep grade) are you going twice as fast? Did the tacho go way past 3,000 rpm before the speed doubled?

If you don't trust the speedo, use a gps, use your phone, plenty of options to assess speed.

Don't forget that the standard classic transfer case is not 1:1 in high range (depending the year the ratio varies). Stretching my memory here but a standard classic transmission gives you about 60mph at 3,000 rpm. In addition of course, you have an engine with a lot more power and torque than the venerable 3.5 litre.

We used to come across the same "issue" when converting Landrovers from Rover engines to Holden engines. The Holden having much more power, did the job much more easily, but at 50mph road speed, it would sound like it was going to come out through the bonnet, revving its ring off. Of course, it was doing the same 3,000 rpm the old rover was, it just wasn't as happy doing it.

Leads me to another thought, what fan are you running? Fixed or thermo? A fixed fan on that set up with be very noisy at road speed.
 

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2002-2005 Range Rover MkIII / L322
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Discussion Starter #10
i got a fixed fan set up at the moment and it is very noisy, i will buy a new fan clutch next week
originally this car was used in racing rally racing off road, it had a holley 400cfm carburator fitted but the engine is the same 4.0L, the car was sitting for about 8 years before i started working on it this year, all I did was remove the carb intake, i did not touch aything else, the car runs excellent just turn the key and it starts almost instantly so I dont think the engine has any problem 20171222_173909.jpg 20190625_164354.jpg
 

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What version ECU have you used? If it is one that is expecting to see lambda sensors then no sensors will give a permanent 0V. 0V on a GEMS with the 5-0V Titania sensors means rich so it will be running a very lean mixture which might explain it. You need to be able to check the live data to see if it is running open or closed loop, although without lambda sensors you won't be able to see whether it is running rich or lean but looking at the fuel trims should give you a clue. What about the knock sensors? Have you kept them? They cause the ignition timing to be retarded if they detect a knock so looking at what the ignition advance is will give you a clue too.
 

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Discussion Starter #12
I am planning to fit the o2 sensors, the knock sensors are not connected, so these sensors could cause the engine to rec up high when in gear? i suspect the transmission or the pressure plate
 

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no the pressure plate is the same because it was ok, only the clutch plate was a little worn, however the new one was a little thicker so the pressure plate was engaged when we tighten it and i had to put washers as spacers to make it work
Hang on? Isn't it supposed to be engaged when the pressure plate is bolted up? It will only disengage when the thrust bearing presses on the pressure plate fingers.
 

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Discussion Starter #14
the fingers were straight when it was tightened, i just finished a test drive using a digital gps speedo, max i got is 45km/h on 4th revs high. you put your foot down and the car revs up but does not pull like it is expected it gradually increases speed even at full throttle
 

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the fingers were straight when it was tightened
But they normally will be on a manual clutch. You shouldn't have needed to put any washers in, a new clutch friction plate will always be thicker than a worn one......
 

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Discussion Starter #16
but without the washers the gears cant be selected, like 1st and 2nd cant be selected and 3rd and 4th can be selected without even using the clutch and reverse couldnt be selected as well, but the way it works is when the clutch is pressed down to the floor the release bearing moves back away from the pressure plate and when the clutch is being released the release bearing pushes the fingers on the pressure plate to push the clutch plate therefor causing the pressure plate fingers to be flat
 

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Discussion Starter #17
i have an LT77 with a chain driven transfer box, will this gearbox make my land rover 90 fast on the road? I am not interested in offroad capabilities honestly coz it is not why i am building this car for, i wish it was possible to have selectable 4wd instead of full time 4wd
 

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the way it works is when the clutch is pressed down to the floor the release bearing moves back away from the pressure plate and when the clutch is being released the release bearing pushes the fingers on the pressure plate to push the clutch plate therefor causing the pressure plate fingers to be flat
Sounds like you have an incompatible mix of bits. When the clutch pedal is pushed down, the release bearing should move towards the pressure plate and press against the fingers so releasing the clutch. If it is pushing against the fingers when released, then the clutch will slip.

Gearbox and transfer box combination won't affect the top speed, that is down to the diffs and overall gearing.
 

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Discussion Starter #19
well in that case I think the pressure plate was not working because it was not releasing when the clutch was pressed and the car was in gear because as i try to start it it would move
 

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Are you missing the pivot for the clutch release arm? If the clutch slave cylinder is pushing away from the pressure plate, then there should be a pivot for it to bear against so hydraulic pressure pushes the release bearing against the pressure plate. That pushes the fingers in which releases the pressure on the friction plate. No pressure against the fingers means the pressure plate is holding the friction plate hard against the flywheel face. Have a look at this explanation of how the clutch is supposed to work https://www.youtube.com/watch?v=pqF-aBtTBnY and you should be able to work out why yours isn't. The engine will but the car not accelerate if the clutch is slipping due to insufficient pressure on the friction plate (probably because of the washers you fitted, assuming you fitted them between the flywheel and pressure plate). The clutch not disengaging will be due to the release bearing not moving the fingers far enough.
 
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