HELP no revs when I press the accelerator

HI
Please help
I drove up to Birmingham today from London in my 2.4 JTD 156 SW with no problems but later popped out to get some fuel and the car would not accelerate at all , floored it to get to 1500 revs and about 10 mph. Parked up had a look started her up again and still the same.
Then suddenly all the power came back. Called the RAC and he could find no faults after putting it on diagnostics. The engine warning symbol had been on for a week or so and I had fitted a tdi chip but have now removed it as I am worried that might be the cause.
Rac guy has put out the warning light and I test drove the car for 14 miles with no probs but after returning and turning off for a few mins and restarting again the same thing happened . Starts fine, idles normally, press the accelerator and the car struggles to rev, foot to floor and you get about 2000 rpm .
Please help as I'm potentially stuck a long way from home and dont want to get ripped off at an Alfa dealer tomorrow.
Thanks
Andy

The injection system is controlled by the engine temperature if the temp sender goes in messes the metering. The sender sits on the end of the thermostat. But equally if there is a high resistance on any of the connections it all goes a bit pear shaped.

I had the same problem in a diesel Punto but half way to Montpelier!

You could clean all of the connections or any garage with a diagnostic machine should be able to check the system for fault codes. Guests (Alfa) in Solihull are ok if you get really stuck.

sounds like intermittent egv valve fault leading to no boost.

That's egR valve, but the car would still rev (just slower pick-up), now if you have the drive-by-wire system we could be looking at an intermitent throttle pedal snag, I replied to a post on this yesterday explaining the codes and why.

Originally Posted by Smaky

That's egR valve,

yeah i know, but my keyboard seems to disagree.

Originally Posted by jug

yeah i know, but my keyboard seems to disagree.

Turn your keyboard round then

did you make any progress?