1998 Avensis 7Afe Sputtering/hickups At Highway Speeds.

[pihx]

Hi all.

My automatic 1998 Toyota Avensis with a 1.8 7A-FE engine has started sputtering slightly while cruising on the highway at 90-100 km/h (60mph?). It only seems to do it around that speed or around 2300rpm. As soon as i give it some more gas or let go of the gas, it's fine. It's also fine driving around town at lower speeds.

I've only had it for a short period, so i don't know too much about it's history.

Could it be air, fuel or spark related?

[Sneakypig]

I've got the same problem, we did the plugs, leads and replaced the coils as the local Toyota dealer instucted us to do, that fixed the major misfire but still has this rough running at just over 2000 rpm light throttle, and feels like it is running a bit flat at that rpm. I have now been told (yet to test) there is something about a set of butterflies in the intake manifold that control the "lean burn" and there is a control diaphram that may be faulty.

My question to the guru's out there, is how to test this, I suppose hooking up a vacuum pump and visauly check operation would be a start, but to test while driving with the fault on may be harder.

Any ideas would be helpful.

Thanks.

[Konrad C]

I've got the same problem, we did the plugs, leads and replaced the coils as the local Toyota dealer instucted us to do, that fixed the major misfire but still has this rough running at just over 2000 rpm light throttle, and feels like it is running a bit flat at that rpm. I have now been told (yet to test) there is something about a set of butterflies in the intake manifold that control the "lean burn" and there is a control diaphram that may be faulty.

My question to the guru's out there, is how to test this, I suppose hooking up a vacuum pump and visauly check operation would be a start, but to test while driving with the fault on may be harder.

Any ideas would be helpful.

Thanks.

Make sure that the rod from the vacuum switch to the inlet valve control has not disconnected. It happened to me. I posted a fix with photos a while back.

There could be another issue since the car is an auto.