Engine changed low rpm power loss

So recently I had a td4 engine replaced on mine it was at 160,000 and although I cannot say for sure exactly what it was that went I do know that once we took it out and turned with a breaker bar using the crank shaft pulley something went *clunk-snap* and then seized solid.

Since getting the new engine at 88,000 miles and having it fitted we noticed only afew differences first the modified fuel rail pressure sensor loom was not on this engine, second the MAP? sensor on the intercooler pipes at the front was non existent and no wiring for one either (retained loom and other assorted parts from old engine.)

My power loss seems to be between 1000 to maybe 2250 rpm ish I believe this is when the turbo kicks in but was under the impression the VNT turbo worked below 2.5, I have checked vacuum lines replaced all and swapped out boost valve including checking the actuator moves by putting my hand up there (don't do while hot).

I don't feel the pipes swell when revved until what sounds like quits high in the rev band maybe 4000 but can't say for sure (women on throttle) I have no whistling and can't see any boost leaks either I can hear the turbo at around 3000 aswell.

Any ideas from my uhh brief description what could be the cause oh and a EGR is fitted to this new engine not yet removed.

Was the turbo off the old engine or did it come with the replacement?

Came with replacement I haven't ruled out vanes sticking.

Was the MAF from the old engine and maybe ok or from the new one and would need replacing? 88k could still be the old one. Sounds a bit like mine.

When the old engine wasn't knocking its nuts off it ran perfectly so yes I can assume the maf is okay but I haven't swapped them however the maf that came with the new engine is still on there.

Does it puff out any smoke? Colour?

Col

Actually no smoke of any sort that I have noticed can't comment when driving but haven't seen any.

I had a similar issue when I changed the engine in a Lancia beta coupe. The cam belt broke and caused a lot of damage. I was offered a low mileage, accident damaged car for a bargain price so I took the engine out and put it in mine. The power drop was significant but it ran smoothly. It turned out that the cam shaft in the replacement engine was a lower profile, don't ask me why.

Col

Engine code was the same and definitely doesn't feel like lower profile cams is causing it fingers crossed might take awhile to reach that conclusion.

The only thing I can suggest is giving the replacement engine a good service and make sure all of the settings are correct.

Col

Well I think my next attempt will be to replace the engine wiring loom with the one from the original engine as that loom has the fuel pressure sensor mod on it and has a cable for the air temperature sensor at the front of the intake that is not on the engine and see if that improves also want to refit Egr blank and change air filter and oil separator while swapping the MAP sensor at same time.

If you're missing a sensor, then the ECU will be substituting it with a fixed value which won't be optimal. Are you sure you're replacement engine is working correctly, especially the injectors and turbo? Is the inlet manifold clean off goop, MAP sensor clear and so on?

Disconnected map sensor and took it for a drive made no difference does that rule the MAP sensor out?

Ive no experience with these but had similar issue on a saab.

Do you have to use your old ecu on an engine change or 1 from the new engine? Maybe different settings/Missing remap/egr if using a different 1.

You mentioned a few differences so hopefully these were just missing parts as opposed to a different year engine.

Hopefully just missing a good service!

CShand said:

Disconnected map sensor and took it for a drive made no difference does that rule the MAP sensor out?

Click to expand...

Not necessarily. Are you able to view the live data from the various sensors? That's the only sure way to diagnose what's up.

Although the engines are the same, it sounds like the replacement is from a pre facelift TD4.
So, take the wiring etc off the duff one and stick it in the new one. They're are slight differences between 1999-2003 TD4 and 2004 onwards, as you've seen with the front pipes/ sensor. This could explain the loss in power as the ecu is not recieving the correct info.
Mike

I cannot view live data myself but will buy something that can on Friday but may take time to arrive in the meantime I will swap the MAF then Egr blank lastly change the wiring loom.