1994 fd. Aftermarket exhaust is all that's on the car. 124,000km on orig engine.

Spark plugs and wires replaced on sunday.
New fuel pump last summer but only about 10,000km on it.
Fuel filter replaced shortly before fuel pump.
Idles around 1000rpm.

Ok so this hasn't been happening all the time. It's been pretty random but not as random anymore. I get pretty big hesitation anywhere from 1000-3000rpm under light load. I can get passed it with no problem with extreme light pressure and then drive to my hearts content above 3000rpm. Revs out of gear no problem. It feels like it's getting gas, then no gas, then gas, and so on.

Pretty sure I have a leaky injector but unsure how to test. I get fuel smell in higher rpms when I punch it.

I am under the impression that my car just doesn't run well under 3000 because every time I creep past 3000 it's like I get a little shot of nos.

And this morning, every time I come to a stop my rpms drop to 500 and bounce between that and 700. Car doesn't stall out.

 

Its a well known flaw that the stock ECU/Map can sometimes have a ~3k rpm hiccup. Some have solved this issue with additional ground wires. 99% of the time this problem is solved when upgrading to a standalone. I'm unsure if this is the same hesistation you are experiencing, but it is likely.

Other than the ECU hiccup, it could possibly be that your TPS may be slightly miscalibrated causing the ECU to misread the amount of throttle applied.

Leaky injector can be tested by hooking up a fuel pressure gauge in your Fuel Feed line. Car will loose pressure very quickly if you have a stuck/leaky injector. Often, a leaky injector will present itself at cold-start with tons of gasoline smelling smoke/vapor as the motor has been flooded in one rotor. I've had this happen years ago. Problem was identified with a quickly dropping pressure gauge after turning engine off. However, I don't think smelling fuel at high rpms necessarily means you have a leaky injector.

 

Thanks for the quick reply. I'm well aware of the ecu problem. Seems like it's more then that. Forgot to mention that after replacing my fuel pump the hesitation became more prominent. I'll check the TPS when I get home from work.

Fuel pump is from carter. Suppose to be an OE replacement.

 

Checked the TPS and O2 sensor and they are fine.

Those were the only connectors I unplugged/replugged and when I started my car this morning there was consistent blue smoke and sounded like it was on one rotor.

 

You started the car with those sensors unplugged?!

You wont be able to tell if the TPS and O2 sensors are bad just by looking at them. You would have to replace them and see if the problem gets better.

 

I didn't run with TPS unplugged. FSM says to unplug the o2 sensor to test it.

 

Popped the map sensor vac hose off without realizing it. So this mornings issue is fix.