Happens more in higher gears at partial throttle. Lets say I'm cruising in 4th, as I go from 3500-4500 RMP and hold the gas pedal steady (partial throttle, applied slightly) the car jerks as if I hit the pedal in all of the sudden, but I don't, it just simulates that for that .1 of second. Anyone knows what causes that/how to fix it/problems from not fixing it?

My car: N/A b18c5 with P72,Hondata.

Before the problem: stock 240cc injectors, stock f.p.r. and ignition base timing set at 16.
Problem started after the following installed/changed: 370cc injectors, b&m f.p.r set 5-6 psi lower,ignition base timing set at 18.

 

ttt

BTW...370cc injectors on a NA 1.8L, yikes! Man you could run the pressure at like 30 psi.

 

o.k. looked up what the stock pressure was.. helms said 47-54psi

current pressure is around 44psi..

 

I have the same problem I am running 440 CC injectors with Hondata. It is not a major stumble, just a little hiccup for 0.25 of a second. Always scares me when it happens though.

 

what is your base timing? and what fuel pressure with the hose of? just trying to compare to mine.. hoping its a simple problem..

 

this happens to me also, i'm running 440s with a hondata, this is also happening to gruvytune (well at least it was when i got mine tuned) i'm really not sure what causes this though.

 

This is an issue for the individuals who are running hondata and other reprogramable ECUs. The problem lies not in the program but many times come from the differences in the cams, i.e. difference in lobe sizes (primary and vtec lobes). You may wantto find out where you v-tec point is set. Often than not it will probably be in that rpm range.(4500-5500) However every car is different. Also remember that Hondata adjust for the size increase in the injectors.

Just a thought or two.

 

My car does the same thing at partial throttle. It only happens around Vtec, 5200 rpms. I'm not running hondata, but do have RC 310's and a "chipped" ecu. What would cause this?

 

can be from differences in timing on the ecu

 

My base timing is 16 degrees and my fuel pressure is 48 PSI with the hose off

 

so i guess it has nothing to do with base timing since mine is at 18.. and pressure isn't that much different from 44psi