91 Civic hesitation when hot

1991 Civic DX , 1.5L, fuel injected, 130,000miles. I'm experiencing
a problem with my car after its parked for a short time. It starts
fine, but hesitates upon acccelerating, and then runs great. A cold
start and go(over night), and it accelerates fine. Feels like its not
getting fuel. Any ideas why it would hesitate on take off when the
engine is warm?
Thanks
............Scotty

 

1) O2 sensor(s.) Before trying to replace them there are several ways to
diagnose it. Step on the throttle (gas) a little wide under load, if the
ECU recognizes this problem for over several seconds then a check
engine light could pin point the sensor(s) for you. Sounds like it doesn't
hesitates for too long, otherwise you would've already gotten a code.
Then there is the O2 sensor test using a high-impedance multimeter.

2) Low fuel pressure? Put a vise grip clamp on the fuel return line to
see if the problem goes away.

Rick

 

Thanks for the tips. Going to check it out this morning. Have a trip
planned for the car this weekend and concerned it will will me
stranded.
........Scotty

 

much more likely to be dirty fuel injectors - especially the auxillary
one [top one] that doesn't see as much throughput. run a couple of
tanks of good quality gas with injector cleaner through - it'll be just
fine.

 

If it hesitates when accelerating then cruise fine then it could be a dirty,
sticky or loose injector; or the ignition system. If it hesitates only
above 1300-rpm then cruise fine then likely it's the O2 sensor, EGR
etc.

 

Hi Scotty: Got the same year Std HB (150K miles). Had slight
hesitation problems while accelerating and cruising at hwy speeds. Ran
a bottle of Regain (Gumout) through the engine/fuel system and that
cleared the problems (thus, dirty injector/s in my case?). As others
have suggested also, why not give that a try? (Others swear by Chevron
Techron fuel system/injector cleaner.......your choice).
Hope this helps.............

 

Well ,just got back from long trip with the car. 2 tanks of gas and 2
bottles of injector cleaner and the car never missed a beat. A cheap
fix for a change Thanks to all that replied.
..........Scotty