Thread: TDI variations in performance.

My 300Tdi see's 4500rpm every day, but only briefly. It's been to 5000rpm on the odd occation. Reving is no problem. My injectors have done 350,000k's. I'm not convinced about the correllation btn performance and tappets yet as my brother-in-laws Tdi with recon head, 200,000k's and freshly adjusted tappets is a slug?

IMO a factor here is fuel delvery settings on the injector pump..mine was a slug with a top speed of 120-130 taking forever to get there....very poor drivability.... A pump tweak and now I am at 140 in half the time...and excellent drivability

Originally Posted by Taz

My 300Tdi see's 4500rpm every day, but only briefly. It's been to 5000rpm on the odd occation. Reving is no problem. My injectors have done 350,000k's. I'm not convinced about the correllation btn performance and tappets yet as my brother-in-laws Tdi with recon head, 200,000k's and freshly adjusted tappets is a slug?

I know that a lot of mechanics inexperienced in changing Tdi timing belts can wind up finishing the job with the injection timing less than perfect.

Originally Posted by joel_nicholson

I know that a lot of mechanics inexperienced in changing Tdi timing belts can wind up finishing the job with the injection timing less than perfect.

agree... my timing belt was not done properly and dropped the performance drastically. Once that was fixed it was back to "normal"
A free flowing exhaust also made a difference to but from comments on the forum, the fuel pump tweak seems to be the the winner in terms of effectiveness. I have done only the first level adjustment ( stop setting ) and it helps. Not comfy about going further without an EGT meter.

Those ones that run well may have had a "backyard" fuel pump tweak that might not be doing the engine much good.

its a land rover thing.

I have driven many 3.5 V8 and afew 3.9s all were different. the best by a long shot was my very first 89 EFI 3.5L V8.

My 300tdi was a slug when I bought it. A 'tickle up' on the fuel pump and adjustment of the tappets by MR Automotive transformed performance and noise levels.

Check the intercooler hoses for delamination as well.

Originally Posted by Taz

I'm not convinced about the correllation btn performance and tappets yet as my brother-in-laws Tdi with recon head, 200,000k's and freshly adjusted tappets is a slug?

Got to agree with Taz on this one I have found tappets both loose and very tight and after setting to correct gap found no performance improvement, (although the slush box smooths out power delivery). As well as performance variations there are both quiet and noisy 300Tdi's too, my sister's sounds like a truck but it kills mine and still returns better fuel consumption figures.

Accelerator cable adjustment.
No good trying to pedal flat out if it isnt pulling the pump wide open!!!!
Our Trytoo suffered from it,mates Rodeo did,met up with a holidayer in Esperance with the same problem(D1 300tdi),one of the Isuzu trucks at work also needs regular adjustment.
Worth a check.
Andrew