4m40 down on power

[BBP]

Hi all,

I'd like to run something past the brains trust if I may.

I think my 98 NL might a bit tired as it feels down on power and the turbo does not kick in like it used to. Don't feel it until 2200-2300 rpm, so I am wondering if it isn't time for some work in that area.

Basic stats:

290Kms on the motor, been looked after (at least since I have had it).

Does not use oil, that I notice anyway.

A while back it was smokey on acceleration and quite gutless, after taking it to some diesel "experts" who appear to know stuff all about the 4m40. I found all the inlet manifold gaskets were stuffed. Replaced all them and it went a lot better. Would hold on hills and could even overtake.

Sometime later I got the timing chain replaced as it was getting very noisy, along with the water pump while they were there. I had a full kit put in chain, sprockets the lot. It was much quieter afterwards.
But I thought the get up and go was not there anymore. Thought it was just me but it is defintely "off". I checked all the vacuum lines to the pump from the turbo etc. They all seem ok. Though I think I will replace the lot anyway.

I had the pump overhauled previously (unnecassarily as it turns out, see inlet manifold gaskets) before the inlet gaskets were replaced.

Is it possible that when the new timing chain was fitted, that the pump timing might have been affected?. Or can I be a tooth out on the chain and not break something but affect the performance?.

The car does not blow smoke at all (that I can see). Like up a hill in 3rd or 4th, foot to the floor and no clouds out the back.

I am thinking that its not getting enough fuel, and therefore not making enough boost. I can get around 11-12 psi on the boost guage. But the car is dead below 2000 rpm.
Or as someone told me the turbo could need an overhaul as they "only last 250-300k".
I have cleaned out the rocker cover "mesh", though I still get a certain amount of oil in the intercooler. Not what I woud call excessive though.

Apart from that the old bucket of bolts goes reasonably well.

Thought I would ask here, before wasting lots of money on "experts".

Rob

[♂Sean♂]

Hi all,

I'd like to run something past the brains trust if I may.

I think my 98 NL might a bit tired as it feels down on power and the turbo does not kick in like it used to. Don't feel it until 2200-2300 rpm, so I am wondering if it isn't time for some work in that area.

Basic stats:

290Kms on the motor, been looked after (at least since I have had it).

Does not use oil, that I notice anyway.

A while back it was smokey on acceleration and quite gutless, after taking it to some diesel "experts" who appear to know stuff all about the 4m40. I found all the inlet manifold gaskets were stuffed. Replaced all them and it went a lot better. Would hold on hills and could even overtake.

Sometime later I got the timing chain replaced as it was getting very noisy, along with the water pump while they were there. I had a full kit put in chain, sprockets the lot. It was much quieter afterwards.
But I thought the get up and go was not there anymore. Thought it was just me but it is defintely "off". I checked all the vacuum lines to the pump from the turbo etc. They all seem ok. Though I think I will replace the lot anyway.

I had the pump overhauled previously (unnecassarily as it turns out, see inlet manifold gaskets) before the inlet gaskets were replaced.

Is it possible that when the new timing chain was fitted, that the pump timing might have been affected?. Or can I be a tooth out on the chain and not break something but affect the performance?.

The car does not blow smoke at all (that I can see). Like up a hill in 3rd or 4th, foot to the floor and no clouds out the back.

I am thinking that its not getting enough fuel, and therefore not making enough boost. I can get around 11-12 psi on the boost guage. But the car is dead below 2000 rpm.
Or as someone told me the turbo could need an overhaul as they "only last 250-300k".
I have cleaned out the rocker cover "mesh", though I still get a certain amount of oil in the intercooler. Not what I woud call excessive though.

Apart from that the old bucket of bolts goes reasonably well.

Thought I would ask here, before wasting lots of money on "experts".

Rob

ofcourse you could be right , if the pump timing is not set correctly the car wont run as efficient as normal , diesels can be touchy little things , it only takes one small issue to create gremlins and take you down the path to nowhere , it surprises me you run 12 psi through the turbo

[BBP]

Hi Sean,

yes, well that is what the gauge indicates. Though it is a "Supercheap" one, so accuracy is likely not its strong point.
I was considering pulling the front off and checking that all the timing marks are right on the sprockets etc. Since that is what was replaced. But before I do that i'd like to know if it is at all possible to be out in this area and still run without breaking something. Past experience with motorcycles would suggest not. Maybe time to get the pump timing and fuelling checked.

[Downunder35m]

Check the connectors and sensors on the intercooler.
I noticed when I forgot to plug them in the enige has nowhere near the power it should have.
You can check the waste gate actuator with a pencil, simply try to get a thick black line on the push rod where it is blank.
Drive around the block and check again, if you can't see any marks in the black it is likely the turbo is not operated properly by the waste gate.
Below 2000 there is not that much grunt, it starts at about 2300 - at least for me.
But if it feels like you got a Fiat 500 engine in your car until you go over 2500 the turbo is definately off (or the waste gate actuator).
How does run up a long hill? Can hold it at speed or is it dropping down much more than before?

[t-rex1995]

maybe look into the the wastegate actuator or the w/gate may have a crack in it had similar problem with a 4g63 starion motor in my dads old pajero years ago

[BBP]

My intercooler only has the temp sensor for the fan. I didn't think that would have any effect. I'll check it anyway.
It used to be much better under 2000rpm, I could feel the turbo pick up around 1800, it would hold easily on a hill. Would even have enough go to pull out and pass someone. Around town hardly ever had to rev it past 2500.
Now on the same hill it drops back and no amount of right foot helps. No smoke either at full throttle, which is why I suspected fueling/pump. I have been meaning to fit an EGT gauge I have, just have to take the time to drill and tap the manifold just above the turbo. With that I could see if the temps were really high on a long climb with the boot into it, if not I suspect not enough fuel. It was like this once before and it was inlet leaks, fixed with new manifold gaskets. So I might go looking for something similar.

I just remembered that earlier when I was chasing similar issues and I had the pump overhauled, thinking it might be the cause. I recall they wound the pump back a bit because of the quantity of black smoke it was producing. They didn't know why it was doing it. Need to look in the book for the right spot on the pump to adjust.

hey Downunder, how are you going with your instrument pod replacement. I am playing with a similar project. Still deciding whether to use Arduino or PICs I have lying about. Or use something like the maximite. Which has VGA out and can take a keyboard etc. So I could display all info on a bigger screen. Or go simple with some basic LCDs.
I have been looking at monitoring fuel consumption on the 4m40. The electronics should be straightforward(said tongue in cheek). Its just the cost of and finding accurate level flow meters, ath won't imped fuel flow. If I recall the pump only uses what it needs and returns the rest to the tank. Least I believe that's how most diesels do it. I know my fuel injected bikes do. I am not sure whether the flow is constant or changes depending on the engine revs. So one flow meter in the main line, one in the return and the diff should be what you have used. Then link to the speedo for distance/speed or use a gps module. The coding will be the fun part(not).
I am tempted to get one meter and see how it goes.
Anyway back to poking around that engine.

Rob

[Downunder35m]

I played with the Arduino Mega as I ordered two for a milling project that still needs motors and many other parts.
Coding some functions is not really the big problem, the problem starts with the sensor readings.
I noticed that there is little info on how to calibrate to unknown sensor values.
Finding the right infos for the standard sensors is not much easier either.
A simple 2 line LCD should be enough if a menu is included and will fit nicely into the instrument cluster next to the cam screen.
Right now my time is too limited to program suitable routines as I just started with Arduino
I know it is possible to store the reference values into the EEPROM part but that only helps once the sensors are calibrated and will be a pain for everyone with different sensors.
Next problem is to get the menu and reading functions working so that there no delays causing wrong sensor readings.
Biggest pain is that you find a lot of useful code on the net, but only parts and with all the libraries missing, so it is a game or trial and error
Programming it in visual basic would be much easier but the additional hardware to use it on a small stand alone device is too much, Arduino is under 60bucks with LCD.
On modern cars it is easy to tap into the lines for the board systems but my oldie does not have any useful infos to share that way ROFL