Engine hesitates at low speed/RPM

**Paddy Honda** · 14-10-2011 10:03 AM

Hi guys,

I've just completed my rally car build with a B16A into an EG6.
Anyway, engine started up fine and no issues running in the garage. Took it out for a spin and after it warmed up, when crusining in traffic, just feathering the throttle, it hesitates/dies for a sec and then comes back. No issue under full throttle, just seems to be there when I'm trying to keep at constant low speed.

Now its searched here and have spent 2 days googling. What it seems to sound like is an O2 sensor issue. I have an ODB1 ECU with the single, 4 wire O2 sensor located near the gear linkage.

Any help/suggestions, must appriciated. Thanks

**nugget** · 14-10-2011 11:33 AM

i had similar problems to yours..
engine will rev normally and at abt 3k rpm, hesitate, then rev normall to redline.

i took my injectors out and took it to the local parts store to get flowed, cleaned and then flow.

engine now revs smoothly, no hesitation and sounds really good.

**justin333** · 16-10-2011 06:36 PM

i got the same problem with u be4, took it to my local workshop and the guy said is the problem of your TPS,
replaced another one and work like a dream*

**trism** · 16-10-2011 06:41 PM

does it throw a code?

**dc2r-0636** · 16-10-2011 06:42 PM

b series are prone to dizzy failure. which resaults in hard starts, and misfiring

seems lyk your ICM is on its way out, or you can just buy a new dizzy off ebay, make sure its obd1 plug.

i had this problem and replaced the spark plugs, worked fine then afta 1,000kms it started playing up again.

**Paddy Honda** · 17-10-2011 07:53 AM

No code, idles steady except that it idles at 1500rpm.
Its odd, at around 2000rpm if you are driving at low speed, it just kinda kangaroo hops a bit. It like the ECU drops the revs and bring it back again.
I've tried the idle adjust but it wont bring it back down any more.
If I put my finger over the hole in the throttle body for the EACV, then the revs drop to about 1000RPM.
Could this be the issues, could the ECU be trying to bring the revs down?? I'm out of ideas.

The car got its first proper run yesterday and under full throttle there is no issue at all, runs great. Its just when trying to hold the car at a constant speed at around 2000rpm.

Thanks

**Glocker** · 17-10-2011 09:09 AM

Hmm I have this issue as well, but this only happens when the car isn't fully warmed up yet; like if I just start up and drive off, or even if I've let it warmed up and it's idling around 1000rpm, sometimes I'll have this 'dead-spot' feel as well.