2.5 diesel

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dogsbody

dogsbody

Very senior member
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10,685
Location
Bristol
This is a very basic question for all you out there with a P38 with the 2.5 diesel. I bought one of these a couple of months ago and I love it. (Why do I think that those words are going to cost me money!)

Anyway, as everyone else seems to say, it is gutless.

I'm learning to live with this by almost flooring it, especially when it's cold, to pull away from junctions. Once I've got going I quite enjoy it's lazy lumbering progress.

However how do I tell if this is the normal gutless? How do I know that my torque convertor or gearbox is not responding correctly? Should I be hitting 2,500 - 3,000 revs to pull away from stationary?

When I first bought this I put it into my local Indy and he did the major 96,000 mile service that involved replacing all of the fluids so I'm assuming (yes I know that's a dangerous word) that the gearbox is full. There is a box fitted as if it's a power upgrade but no name on it. I'm tempted to remove it but not until I know a bit more.

So, the seemingly simple question is, what is gutless and what is faulty?
 
See if anyone near you is up for a meet? On a private road, obviuosly, try a drag race against a similar vehicle the owner is happy with. Get some one to go along so they can brew up while you`re racing the standing quarter! If you can establish that you do have some form of "black-box" fitted try running with and without it connected. What does this box look like? Do it against the clock not just by "feel". As you`ve had a full service then the most obvious causes of power loss have been taken care of; air & fuel filters. No whistling noises from leaking high pressure side on turbo?
 
dogsbody said:
This is a very basic question for all you out there with a P38 with the 2.5 diesel. I bought one of these a couple of months ago and I love it. (Why do I think that those words are going to cost me money!)

Anyway, as everyone else seems to say, it is gutless.

I'm learning to live with this by almost flooring it, especially when it's cold, to pull away from junctions. Once I've got going I quite enjoy it's lazy lumbering progress.

However how do I tell if this is the normal gutless? How do I know that my torque convertor or gearbox is not responding correctly? Should I be hitting 2,500 - 3,000 revs to pull away from stationary?

When I first bought this I put it into my local Indy and he did the major 96,000 mile service that involved replacing all of the fluids so I'm assuming (yes I know that's a dangerous word) that the gearbox is full. There is a box fitted as if it's a power upgrade but no name on it. I'm tempted to remove it but not until I know a bit more.

So, the seemingly simple question is, what is gutless and what is faulty?
Click to expand...


Definately gutless when cold, as is my Transit diesel. When hot it can seem a tad lethargic which it seems to me is due to the heavy and long travel accelarator peddle, boot it and it goes:D
Mine has a PSI power box fitted, it's good for 80mph plus with the caravan on the back more when running solo. It revs out at 4500 or so when shifting gears.:D:D:D
 
Could be a few things, for a start. MAP sensor duff. Fuel lift pump duff. Make sure all vacuum/pressure lines are sound. Diesel engines with rotary fuel pumps can run with totally defunct lift pumps. One of the loss of power cures in tech bulletins is replace in tank fuel pump if the flow rate is down. 180ml per min, if it's less than that it is duff. The FIP relies on a positive internal pressure to operate efficiently, this is supplied by the lift pump, if it has to suck fuel out of the tank it cannot work properly hence low power.
 
Anyone know what a 0-60 time would have been when new? And what times are your vehicles making now? Both with and without chips? Trouble is "sluggish" ain`t a very accurate measure! If Dogsbody`s car is noticably slower than another similar, then do some work, but if he`s expecting too much, then chip/tune up. When I finish tea break and grass cutting will try mine, but as a manual with slow synchro it won`t be much of a comparison. Suggest 0-60 and 40-70? Worth a go? Any suggestions? Obviously we`ll all have to hire a private track for a while; I wouldn`t encourage using the Queen`s highway for such a thing!
 
wammers said:
Could be a few things, for a start. MAP sensor duff. Fuel lift pump duff. Make sure all vacuum/pressure lines are sound. Diesel engines with rotary fuel pumps can run with totally defunct lift pumps. One of the loss of power cures in tech bulletins is replace in tank fuel pump if the flow rate is down. 180ml per min, if it's less than that it is duff. The FIP relies on a positive internal pressure to operate efficiently, this is supplied by the lift pump, if it has to suck fuel out of the tank it cannot work properly hence low power.
Click to expand...
how exactly would you go about measuring such flow rate?
 
Thanks for all your interest.

The other reason I'm asking is that, for a comparison, during the week I drive a Merc Sprinter van with a 2.3 turbo diesel. O.K. it's manual but in a traffic jam I can just let the clutch out in first and it ambles along at about 10mph. In a drag race it would murder my Rangie, and the Merc has over 375,000 on the clock - original engine and box. I rarely rev the Merc over 3,000 but I'm getting close to this just to get the Rangie to move.

So, is there anyone around Bristol with a 2.5 auto who would like to run a comparison?
 
I'd have to go with Datatek - Rangies always seem slow at first when you're not used to them due to the long pedal travel which you don't have in cars - even the 4.6. It always seems against the grain to give it so much wellie just to get going. It's why a lot of modern cars with fly by wire throttles have the response tightened up when you hit the sport button. It doesn't make them any faster but it makes it feel like they are.

The lethargic pulling away from junctions waiting for the turbo boost to come was one of the reasons mine had to go. Fine when it was bowling along but pulling out at roundabouts with a large caravan on the back took some forward planning.
 
Lemme get this in me head ...............you have to rev the engine to 3000/3500 to get it to MOVE!!!!

Sounds like the Torque converter is shagged or the gearbox is cream crackered

What happens if you drop it into "1" (Rather than Drive ?????????????????)
 
bart2181 said:
how exactly would you go about measuring such flow rate?
Click to expand...

Read RAVE it is explained in there. Get yourself a measuring jug, remove fuel pipe from filter, put in jug. Remove relay R12 in fuse box. With ignition off take supply from battery to terminal 5 on fuel pump relay. Contact this for exactly 10 seconds. Pump must deliver at least 180ml of fuel.
 
Last edited:
I've found mine has improved with use, I don't know if the adaptive ECU adapts to driving styles and the previous owner was a bit of a bumbler, but the more I drive it in a 'spirited' manner the better it gets... of course all things are relative:doh:, so I'm still aiming to add a powerbox of some type.
 
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