Slight Shudder / Hesitation.

[Avensis luna 03]

Our Avensis 1999, 1.6 Leanburn Engine, is intermittently inclined to shudder / hesitate when you apply any amount of accelerator when the engine is running at under about 2500 rpm. Its doesn't seem to happen or is not noticable above this engine speed. It seems to run fine besides, no problem with power or idle consistency. New plugs and air filter installed. All pipes seem in perfect condition.

Any ideas or help would be much appreciated.

[woodie]

Our Avensis 1999, 1.6 Leanburn Engine, is intermittently inclined to shudder / hesitate when you apply any amount of accelerator when the engine is running at under about 2500 rpm. Its doesn't seem to happen or is not noticable above this engine speed. It seems to run fine besides, no problem with power or idle consistency. New plugs and air filter installed. All pipes seem in perfect condition.

Any ideas or help would be much appreciated.

hi,

2004 avensis d-4d 50k has failed to respond to the accelerator on a number of occassions. toyota failed to diagnose fault as it does not show up when testing. normally drives fine. Mystery?

[Avensis luna 03]

Hi Woodie,

I saw your post on this earlier alright. I didn't make a connection at first but maybe there is.

I'm still at a loss to know what is causing this. I was thinking along the lines of something do do with the fuel filter, vacuum system etc but all these seem fine.

Like your own situation, the fact that it's intermittent really makes it difficult to figure out.

Mine has passed the NCT with this problem so its not anything too major (or detectable!)

Only thing that I did notice was that the high idle CO2 readings in the NCT were highish, very near the max allowable in fact, so maybe this has something to do with it.

I wouldn't really describe mine as a failure to respond to the accelerator. It's reallt just this hesitation as if the timing went out of range for split second or so.

Anyway, we'll have to see. In a way, I'm waiting to see if it will get worse and if it becomes more consistent, then 1. I'll have to get it sorted and 2. It might be easier to find.

Hop you get yours sorted. If I think of anything else on your issue, I'll be back.

Rgds.

[Avensis luna 03]

Well, I finally figured it out and I thought I'd post back in case it might help someone else.

With a little help from the local Mr. T, we diagnosed a faulty spark plug lead. So I replaced all 4 and the plugs. Now drives like new.

If you look at the affected plug, you will notice thin black line(s) running down the porcelain, indicating the stray spark.

The leads are €104+VAT so not cheap from Mr. T but on the other hand they took it in and diagnosed it for free, only 25mins but still appreciated! So can't fault them.

All's happy here!! :D