Hi all.
My 1998 4Runner (Hilux Surf) is driving me to distraction. I have just replaced the cylinder head and since I put it back together it starts and idles beautifully but often when you press the throttle to accelerate she seems to bog down but if you put it to the board then she takes off like a scalded cat. All 16 valves are new, all genuine Toyota gaskets and parts were used and it has cost a small fortune but it is really annoying. The CEL light is not on and I don't think that timing is an issue because she runs perfectly apart from this horrible flat spot. I have owned her for the last 15 years and this is the first problem she has had other than routine servicing. The plugs leads and dizzy cap and rotor arm are all new.
Does anyone have any ideas ?

 

did you ever figure this out? curious of the cause, thanks.

 

Hi there. I have still got the problems. She has settled down a little but she is still way off being right. I am going to buy new O2 sensors and various other sensors etc to try and resolve the problem.

 

i knew i asked this somewhere and took until right now to find it.

my V8 at 145k does something a little similar. i notice that if i'm not rough on it, making it kick down gears, she likes it better. its forced me to drive more conservatively, which is probably a good thing. but no idea what it is.

 

Hi there.
The short answer is no. I am sure the knock sensor is faulty, or possibly the wiring. I really need to sort her out now. It is driving me mad !!!