OK, here’s the lowdown. My 4Runner has begun hesitating sometimes during acceleration AND immediately after acceleration. It feels like it is “chugging.” This usually also happens in the low end of gears (it is a manual 5 speed). I do not believe it is the transmission as I do not notice it slipping at all. It has been 90,000 since the timing belt was changed, which I plan to do soon. Could it be an injector issue? Maybe a cylinder is not firing? The RPMs do not seem to change much when this occurs. Any trouble shooting help before I go tearing under the hood would be appreciated.
Thanks
Alex
Check your vacuum hoses especially the one to the brake booster for cracking.
When was the last time the fuel filter was replaced? If you don’t know or can’t remember, that’s where I’d start.
Tester
I like @Tester’s thinking. It sounds like a fuel related issue to me also. Along with the fuel filter change you might check to see if the TPS sensor is working correctly and doesn’t have a dirty spot. Cleaning the MAF sensor might help also. If none of those things are causing the trouble it might be good to check the fuel pressure.
+2 for @Tester. I would get the fuel pump pressure checked as well.
Another possibility is a sticky EGR valve.
I feel like it is fuel related as well, I have a new filter waiting to replace the old…just haven’t gotten to it yet. @Barkydog, I had a vacuum leak last summer so I am going to start there since I know the system already.
As for the fuel filter, I did not replace it a few months ago because the problem suddenly went away, would it make sense that the filter had somehow cleared itself? I think a vacuum leak would have not suddenly disappeared like that…