Well, my motor was running fine for awhile, it felt a little slow on bottom end but when vtec hit it was fine, I had a TPS cel so I assumed it was that. last week I installed a vafc and things went to ****.

it hesitated really really bad, barely got to 25 mph and limped it home from my friends where I installed it.

I re-wired it, cut the map sensor wire which I didn't do the first time, hooked it up and it ran, but it still hesitated a little bit, but when I got to 4500 rpm it just let go and pulled real hard. but anything under that it hesitates real bad. Today I took the VAFC out and it was doing the same thing

idle is normal, No Codes, new O2 sensor, good TPS sensor, map sensor seems fine. it's not the ecu. and timing is fine. just when I press the gas it barely revs up, like something is really holding it back

there is black soot splatter out the exhaust, and an oil leak near vtec solenoid. those are the only abnormal things.

 

bump, I still need help

 

try changing the sparkplugs and wires

 

I'm going to try out, plugs, wires, cap and rotor. any other suggestions?????

 

good luck on finding the solution...i have been trying to figure that out for a while now...there are a few good threads on this hesitation problem
...there are a bunch of suggestions in those threads on what the problem could be and the probable solution...

 

New plugs usually fix problems like that. If not, I'd replace the fuel filter.

 

Fuel filter is new, I just replaced the plugs, map sensor, TPS, and O2 sensors are ok. so I was leaning towards spark plug wires and rotor.

but last time my rotor went out my car wouldn't start at all.

I want to borrow someones wires and rotor before I go out and spend money on them and realize it doesn't fix my problem.

Also when I searched I couldn't really find an answer.

 

Have you reset your ecu ?

 

I reset it after I reset the VAFC, but I'm not throwing any codes, but I'll give it a try, maybe something will help.

 

Try checking your injectors....try a fuel injector/fuel system cleaner along with high test fuel.....I use to get black splatters and smoke when my teg was outta time but u say urs in in correct time...usually hesitation comes from too much fuel or not enough....check everything fuel related....

 

the black **** from the exhaust is usually from running rich. Do that complete tune up you have planned... then afterwards.... Properly Reset the ECU then let it idle for the proper time to recalibrate the AIR/Fuel ratio. Then shut it off and start it back up. Good Luck


Also, is your VAFC adding a **** ton of fuel at low RPM ? you didnt mention how you had your VAFC set

What is your Fuel Pressure set at

 

I mentioned up top that I eventually took the VAFC out.

The thing that doesn't make sense is that it ran fine before I messed with the vafc. a little rich from the Mugen chip, but other than that it was just fine.

All I did with the VAFC was I wired it wrong at first, it bogged out really bad, I could barely drive it.

then I wired it right, and it was ok, but it still hesitates a lot. Now I wired everything back up to stock and it does the same thing, hesitates when I hit the gas.

I changed out, O2 sensor, TPS, spark plugs, map sensor is good and it's got a new fuel filter.

so now I'm just going to try wires and rotor, and anythign else people suggest

 

bump

 

ttt

 

hmmm i wonder if your CHIPPEd ECU still recalibrates air/fuel ration with a proper reset.

How many miles is on it ? why not run some seafoam through it

 

I'm running a PR3 on a fresh built motor, GSR block, itr head.

it shouldn't need Seafoam yet. Also, I did try an LS ECU and the effect didn't change, still hesitates real bad. very slow revving

 

ahh fresh motor .. ok .. well maybe still have distributor problems? i have one of my own .. but i was reading about this guy with an ITR 9k miles his was hesitating and it ended up being his ignitor i believe ... do you have another distributor to swap just to test ?

 

Nope, no extra distributor for right now. I thought it'd be less headache to stay with Non-obd, and I guess I was kinda wrong about that.

at an idle, when I press the gas the motor revs up really slow, at half throttle it revs up to 3k when it should have gotten up to about 4 in the same time. make sense?

 

maybe it just dont like you

 

hey now. lets me nice

 

do you have stock cams?
is the timing set properly ?

Do you have aftermarket cams?
Where they tuned on a dyno ?

whats your ignition timing set at ?

 

stock itr cams, timing was set properly, ignition is at TDC.

I'm running rich, and now I'm throwing a code 4, so I'm going to change out my distributor and see if that makes a difference.

 

its totally ignition related.

 

This weekend while building my ls/vtec I switched around the map and tps sensor plugs. It would die when I stepped on the gas. I was too stupid. You should check it out.

 

ya, I'm going to borrow a distributor from someone here soon, so we'll see what happens.

and yes, I swear my motor hates me sometimes, haha.

nah map and tps are in the right places