Unlikely to be the ICV - if it was you'd have a problem at tickover.

The EGR valve tends to cause hesitation when cruising on a light throttle. Your problem seems to be on heavier throttle settings - ie acceleration. No probably not the EGR.

You can always clean both of the above - get yourself a Haynes manual and some QuickSilver Powertune (I always recommend this stuff because once you've used it you won't use anything else. Buy from ebay or a boatyard - it's made for powerboat engines.)

MAF/AFM - could be - the symptoms are typical of a faulty AFM. Do not try to clean it, the Vauxhall type do not generally respond well to being cleaned. The chemicals destroy the element. One way to check is to disconnect the AFM. The EML will come on and the ECU will revert to limp home mode - so the car will not run at best performance, but it ought to run consistently. So if you disconnect the AFM and don't get the same symptoms you know why.


Fuel pump & filter. Well the filter should be changed when it's serviced, so if that is suspect you might as well put a new one in. The fuel pump can be taken off the car and tested. I don't think it is the pump or filter as if it was you wouldn't get a momentary loss of power. You'd get a more significant loss of power when the engine was under load.


Air filter - again a routine service item. If it hasn't been changed recently then do it. It is has been changed recently then it ought to be OK.


Now the thing is no-one can accurately diagnose a problem via a forum - we haven't seen, heard or driven the car. All we can do is to make an educated guess based on what you describe. So on that basis this isn't going to be 100% accurate - but from what you say I'd begin with the routine service items. Check your filters, plugs, etc - if it is overdue a service do that before messing about with anything else.

If a good service doesn't sort it out then next suspect is the AFM.

Work through things one at a time - don't try several things at once. That path leads to sorrow and needless expense.

 

ok thanks, i understand its hard to diagnose on here thats why i tried to be as descriptive as possible. Had a thought you can plank of the egr valve right? i Know you said its unlikely but if i just unplug it will it act as if its been blanked off? just as an easy way to test that also?

I changed air flilter, had a few spare quid thought what the hell, and afterwards when my revs get to 3000 it get allot louder then it did before i changed it, before and after the 3000 mark it sounds the same theres no power loss or gain though is this normal? because it was being starved of air due to a clogged up filter(it was very bad) so didnt make as much noise as it would normally?

 

If your air filter was very dirty that would not help at all. Yes it's possible for a cleaner filter to make more noise because you can hear more air being pulled through it. About 3000rpm general engine and road noise would make this not noticeable.

Has replacing the filter solved the loss of power when accelerating? I think you say it has in which case :thumbs_up:

Don't expect a huge extra burst of power from a 12v engine.

 

hmm it has helped and it hasnt, it hasnt done it as often but it still does, it when the engine get warm and has been run allot(mainly half way through a shift at pizza hut) i recently changed spark plugs just to see if that helped (starting with the cheaper stuff and working my way up). Im getting a gasket for the egr valve and going to give that a good clean. I have noticed that when its doing it my revs tend to fluctuate when idleing. I dont know the the icv is caused the loss of power or weather thats just on its way out and causing the fluctuating revs when it heats up but not actualy related to the power loss, ill give that a good clean and let you know.

thanks for the help

 

just an update from a very old thread, finaly got some money together and managed to buy some carb cleaner and a gasket and took of the egr valve, it was seriously full of crap. Cleaned it all up and the car runs grand now, id say its about 90%. Every now and again it does it again, when it does do it its not jolting as it used to but more feels like a huge gust of wind is blowing against you and slowing you, but its 10 times better then it was though so id call it a success. Just thought id update and say thanks for the advice mate