Thread: td5 acceleration delay

Originally Posted by Rat

My 2005 td5 defender is doing a problem on acceleration. It's most obvious on the highway. Doing 100k, put foot down to pass, and nothing for about 5 seconds, then starts accelerating away. It happens most often when started cold. After you have shut it down at your destination, when driving home is back to normal, instant power. If the two blue vacuum lines are pulled off the egr assembly, Problem is gone immediately. LR dealers have replaced the fuel pump, egr assembly, ecu, injector harness (twice), and now tell me nothing is wrong (can't fault it). Someone help me!
Rat

I automatically thought of turbo lag, but at 100kph the turbo would allready be wound up. sorry no idea.

thats what it sounds like to me too......turbo lag....
when you are cruising the turbo dumps the excess boost....
when you floor it.....it needs time to build up boost again....but needs a lot more boost due to the higher revs/speed....?
hence taking a bit of time to spool up.....?


or possibly a sticky valve somewhere such as waste gate.....?

Check for exhaust leaks, leaks in the wastgate, damage to the turbo, intercooler clogged?
Something may be leaking the air out of the turbo system

Then fuel are your filters O.K. injectors clean, no water in the fuel system
Fuel quality (have you been running Biodiesel)

As disabling EGR makes the problem go away, either the MAF or the ambient air pressure sensor (on the airbox) could be faulty, as both are used in determining if EGR should be activated (and the ecu, but that's been replaced), and I'd go for the MAF.

have you had it scanned to check for any fault codes....?

Long shot but check the connections on the crank angle sensor are clean.

Hi Guys
I gave BlackBetty a hiding in 1st low whilst playing in our new playground the other day.Definately found the rev limiter/boost limiter.Kept the boot in,go hard or go home,she was going hard on and off real quick.Yep Im a silly bastard.
Andrew

It has been checked and they say no fault codes present. If the MAF or ambient air pressure sensor was dicky, would there be a code or could one of them just be reading a wrong reading intermittently with no complete failure to log a code. It only sometimes does this problem. Most often if I start it cold then go straight onto the highway. I have a snorkel so it rams the air into it more than without one. No biodiesel either.
Rat