engine hesitation when accelerating

Within the past week I've noticed that my 95 Tacoma 2.4L manual transmission hesitates when accelerating in 1st 2nd and 3rd gears. It seems to be better in 4th and 5th gear.

It happens when I'm first starting out for the day, ie. when the engine is cold.

I've been doing some online searching and some possible suspects are fuel injector, fuel pump, MAF sensor, distributor.

The engine has been leaking oil for a year now. I haven't traced the source yet.

Would a distributor oil leak cause hesitation during acceleration?

 

I recall reading somewhere, here or on other vehicle forums, where oil can get up inside the distributor and short out the components. Pop the cap and take a look.
I would start with the basics... check spark plugs, wires etc before I would go searching for the bizzare.

 

Vacuum leaks tend to be worse when an engine is cool too. You could get a vacuum leak tester or make one without spending a whole lot of money - just google / youtube it.

 

Did it throw a check engine light? I was experiencing just about the same exact thing (hesitation at low rpm on a cold start) and after doing it for a couple hours it gave me a code for a cylinder 4 misfire. I took it to Toyota and they said the spark plugs were in bad shape and they replaced the plugs and that fixed it.

 

I'm going to take into my mechanic tomorrow.

It's definitely only happening on the first time I take it out on the road for the day. After it has warmed up there are no symptoms. So when it's cold and starting out the hesitation occurs only.

 

Good luck. Hopefully it's just something simple like my situation where I only needed new plugs

 

donlogan did you ever figure out what was causing hesitation? I'm having the same problem, I've already used fuel injector cleaner and replaced spark plugs. Getting ready to replace MAF sensor and PCV valve. Thanks!