DEAD SPOT BETWEEN 2500-3000 rpm

Hi I am the proud owner of a 99T 300tdi Auto imported from Japan with a total of 55k miles..the car drives superbly BUT under hard acceleration it splutters at around 3000 revs,picks up momentarily but splutters again..as though the diesel has been turned off and on and off and on etc ..revs ok when stationary its just under load but is a pain when overtaking...have had a guy at Sleaford 4x4 plug his laptop in..showed a faulty crankshaft sensor which we changed..no different...have blanked off the egr valve and fitted new silicone intercooler hoses which has improved acceleration but fault is still there...drove at 3000rpm in third for a while and the fault could be felt but the rev counter started going haywire..so we havent a clue really...when I first got it the throttle behaved oddly at low speed..flat spot..but this cleared..wondering if it could be the electric bit of the throttle but surely this should have showed on the laptop...can any one suggest a cure please....

sounds like fuel starvation, change the fuel filters anyway.

Sounds like fuel starvation to me as well.

Check/clean the fuel sedimenter and a fuel new filter. Bob in a new airfilter for good measure.

Cheers & good luck.

Dave

Similar problem on mine....300tdi auto 125k miles still has egr..

When I accelerate hard it pulls then kind of hassitates like it is going to change gear but doesn't...

Will change the air and fuel filters...will also order a egr blank..... anyother ideas...?

youll need to soak your "NUTS" and bolts prior to takeing the egr valve off some can be easy just done mine 3 days oiling seemed to have done the trick !!!!!

Boatboy said:

Similar problem on mine....300tdi auto 125k miles still has egr..

When I accelerate hard it pulls then kind of hassitates like it is going to change gear but doesn't...

Will change the air and fuel filters...will also order a egr blank..... anyother ideas...?

Click to expand...

Don't forget to clean out the fuel sedimenter, it's often a cause of hesitency.

Dave

Done the fuel sedimenter and it was full of crap....
Also disconnected the wiring plug to the erg thingy...

Wow what a difference...it now pull through the full rev and upto about 4500 revs without any hessitation....

Had a few problems along the way...the plastic screw things on the bottom of the sedimentor snapped...got a face full of diesel..then had problems bleeding the system....

But it's all working again and I am well happy.

Thanks Paul.

Boatboy said:

Done the fuel sedimenter and it was full of crap....
Also disconnected the wiring plug to the erg thingy...

Wow what a difference...it now pull through the full rev and upto about 4500 revs without any hessitation....

Had a few problems along the way...the plastic screw things on the bottom of the sedimentor snapped...got a face full of diesel..then had problems bleeding the system....

But it's all working again and I am well happy.

Thanks Paul.

Click to expand...

Hi Paul, I think you mean the EGR (exhaust gas recirculation) valve. Disconnecting it electrically does not neccesarily stop it impacting on your engine's performance.

I suspect the improvement you are currently enjoying is predominantly to do with the sedimenter now being clean.

To take the EGR valve out of the loop you need to physically remove it from the car, blank off the hole left in the exhaust manifold and replace the top intercooler hose with a plain non-branched one from a Tdi 200.

Kits are available off Ebay.

You will almost certainly have a cat in the exhaust downpipe, I repaced mine with a Defender non-cat version and the improvement in performance is quite remarkable.

Obviously it's still a 2 ton lardy cake, but it goes much better now and I get 34mpg daily, better on a run.

Cheers
Dave

thebiglad said:

Sounds like fuel starvation to me as well.

Check/clean the fuel sedimenter and a fuel new filter. Bob in a new airfilter for good measure.

Cheers & good luck.

Dave

Click to expand...

Yep sounds like restricted fuel caused by blockages.
Done all of the above.
Runnin on veggie i have to clean/replace fuel filters monthly,savings still outway the cost

VEGGIELANDEE said:

Yep sounds like restricted fuel caused by blockages.
Done all of the above.
Runnin on veggie i have to clean/replace fuel filters monthly,savings still outway the cost

Click to expand...

Just for your interest, Rape oil here today is 1.79 euros per litre !!!

So I won't be doing that then as diesel is an absolute bargain at 1.30 euro ltr.

Cheers
Dave

thanks to all the sedimenter was half full with emulsified water now goes well have also removed cat and fitted straight through stainless but with defender downpipe..remarkable improvement..thanks again to all who replied

Do the V8 Disco's have this EGR sensor thing? if I removed and blanked it off would it fail the MOT?

think it only applies to doozils.