Got hesitation + ecm throws code 55-sensors all good = HELP!

[Salem240]

I have a hesitatation (feels like revlimiter) occasionaly under accel. when the engine is warmed up. I did an 5spd swap with a 5spd ecm and wired all the sensors. The ecm was throwing a code 82 after my 5 speed swap so I installed a cps. I checked/replaced all the usuals distributor cap/button, wires, plugs, fuel filter, injectors, vacum lines, o2 sensor, even installed a brand new Walbro 255 fuel pump. Has anyone else had this kind of prob? Any ideas? Please

Ohh and it hesitates either between 750-1500 rpm or 2500-4000 rpm
Modified by Salem240 at 8:05 AM 7/31/2009

[destroyyourmind]

I have the same problem does the car kinda bog when you start it and hesitates real bad under throttle with some backfiring? I've checked all of my sensors as well.

[Salem240]

Yes it bogs on itnitial accel. and sounds just like the rev limiter kicks in if you give it more than half throttle, no backfiring (yet). Timing is set at stock spec

[Salem240]

well, managed to get my throttle position switch replaced just to find out THAT WASN'T IT $#*@ !!!!! anyone have a solution? please help

[VMP]

code 55 means there are no fault codes zerothread?id=253912

as for the bogging... try putting the auto ecu back in and see what it does..

also.. you have a 95 right? just hook up a scan tool to the dlc on the passenger side and get the P#### code that it will give you and go from there. (only works if the check engine light is on) http://www.wallpaperama.com/fo....html

gl!

[Salem240]

Yeah, there is no CEL on .... and I forgot to mention that I swapped the auto ecu back in and got the same problem (and throwing 3 codes for the transmission).

[Salem240]

Maybe a video would help......

Here's the YouTube linkhttp://www.youtube.com/watch?v=DHa2PhKNu-U

[VMP]

82 is crankshaft position sensor

i found this in my old s14 rebuild stuffsss http://i15.photobucket.com/alb...s.jpg

[VMP]

so basically the crankshaft position sensor (or circuit) has a fault in it somwhere or the sensor itself has gone bad.

however if you just recently had a 5spd swap done.. i'd prolly find someone with a fancy scan tool and set it to remember a 10 minute trip while you go out and test drive it... then some back and review the results. it will basically tell you what the ecu is seeing. gl

also... how trustworthy and reliable are the people who did the 5spd swap... perhaps they didn't install the flywheel or clutch right.

[Salem240]

I fixed the code 82 already and installed the cps. Still have the same prob and the ECM is showing no faults. One thing I found was the hesitation happens more frequently and sooner after the motor warms when it's hot outside

[destroyyourmind]

I'm having the same problem mine seems way slower than your video though, I'm going to dyno my car to figure out the specs on the motor and I'll let you know whats going on

[NISSAN240SX12]

i bet its your fuel pump. i had the exact flippin problem.

[Salem240]

i bet its your fuel pump. i had the exact flippin problem.

I replaced it with a walbro 255..... recently I replaced the MAF&intake temp sensor and the front o2 sensor (again). It's cutting the fuel out cause the plugs are white and the o2 sensor I pulled was white on the end. I think the only thing I have left to try is the rear o2, fuel pressure regulator, and egr system (might just remove it. NC has no emissions for OBDI cars)

[Salem240]

For anyone who has the same issue make sure you check your EGR system. After I removed the EGR system and took a closer look at the vacum lines, one of the lines had a really sharp cut in it. It apparently happened when I changed out my motor mounts and pinched against the firewall. The vac lines is one of the first things I checked but I was looking for cracks/dryrot not a "cut". Now that everytihng is removed and blocked off the car runs like a champ. I wish I would have found this before I bought all those parts but oh well.... Lesson learned.... again