Trottle responce

[SiR JDM]

ok well had this problem on and off for awhile now.. ill try my best to explain ..

When I accelerate it is fine, but as soon as I ease my foot off the throtle, the car jolts as if the brakes been tapped... its is significantly more severe at lower gears (im assuming due to the slower road speed im travelling at)...

However sometimes it just goes away (recently Ive noticed its been non existant when its been raining - but this could be just coincidence)

The problem only exists on deceleration, not acceleration, so im kinda stumped.
I heard it could be my trottle sensor.. but im not sure about this or where it is..

Any ideas guys? Im stumpped, sometimes the car just drives smooth and fine no problems..
other times its got this huge jolt upon deceleration, its only small but its evident changing gears...

[Phat_ciVic]

Does it happen when u let ur foot of the accelerator slowly?

[SiR JDM]

Yea it does, but more severe if i dump the accel

[Weq]

what about when u accelerate slowly? do u get a small flat spot? could be fuel related... or maybe an engine mount?

[SiR JDM]

just took it for another spin then.. its not very consistant...
I understand that higher compression engines such as the b16 have an engine brake .. and when decelation occurs, the engine slows ... but it should not jolt and jerk like mine...

If im in 2nd at about 4 thousand and i tape the accel.. the car will jolt back and forth back and forth, very agressive and vigeriously..

Also usually when i accelerate there is a slight jolt, then a smooth acceleration..
I heard this could be due to a build up of carbon on my butterfly?

How could I check weather it is fuel and/or engine mount related?

[imashy14u]

Yeah, it sounds like it's a fuel problem. Things you can do is probably change your fuel filter and have your injectors cleaned. Also try cleaning or changing your plugs and leads.

If you want you can check your throttle butterfly, spray it vigourosly with throttle body cleaner before you attack your fuel system.

to check if it's your engine mount, just turn your engine on and go under the bonnet and rev the engine. If the engine seems like it's moving around heaps (more than normal) when revving the engine, then one of your engine mounts may be stuffed. you can further check it by doing a visual inspection.

Hope this helps. :)

[Weq]

just took it for another spin then.. its not very consistant...
I understand that higher compression engines such as the b16 have an engine brake .. and when decelation occurs, the engine slows ... but it should not jolt and jerk like mine...

If im in 2nd at about 4 thousand and i tape the accel.. the car will jolt back and forth back and forth, very agressive and vigeriously..

Also usually when i accelerate there is a slight jolt, then a smooth acceleration..
I heard this could be due to a build up of carbon on my butterfly?

How could I check weather it is fuel and/or engine mount related?

Seems exactly like the problem i had. It started happening when i changed my injectors. I got rid of it almost compeletly by adding fuel down low with my e-manage. I know u dont have the luxury, but a TB clean will help u out also. Carbon buildup can restrict slight throttle response, so ur TPS registers and adds fuel, but ur butterfly isnt actually letting any air in due to the buildup.

Take off ur intake pipe, get carby cleaner/tb cleaner and a toothbrush and like mashy said, vigourisly attack the butterfly and the insides. Dont be afraid, spray heeps in there, give everything a good clean. Ur car will stumble for a few seconds on startup but it will be good before u know it. carby cleaner is o2 sensor safe so u have no problems.

[SiR JDM]

Thanx guys, exams finish this friday so ill give it ago hopefully then ..

I always thought it was a fuel problem (my injectors mainly) but never knew exactly where and what the problem was.

Because it is an on and off problem i asumed it must have been something to that affect.

Anyway, ill let you guys know how it turns out. thanx again

btw - I changed my sparkies and injectors in the past 1000kms, so i doubt its them..

Is there a way i can check if my injectors are dirty or something?
Would injector cleaner (1-2 bottles as ive been told by someone) be helpful? thx

[Weq]

dont waste ur money on injector cleaner. If u want them fixed, u need them ultrasonicly cleaned and flow benched to make sure they are in good working condition. Ive heard quotes of $15 an injector - but u need to take them out of the rail urself. If u want, ive got a set of injectors hear. I'll let em go for $40, save u some downtime.

[2ds]

before doing all the stuff mentioned above, take out your air filter and see if it's clean =)

-2ds

[SiR JDM]

2ds, the filter is a simota, bout...3-4 months old... ill check it anyway..

thx weq ill get back to you guys on that

are the injectors new.. or just cleaned? are they fit for a b16? reading your posts on Adams CTR I see you know a bit about injector/fuel ...
Thx peepz

[Fredo]

My car has the same (similar) problem and i put it down to the engine moving on the mounts, so maybe the mounts are stuffed. mine engine also feels like it's moving back and forth when i accelerate it's very unnerving.

[J-MuN]

i dont know if i'm havin the same problem as u Jimz but when slowing down, like when coming to a stop at a traffic light or jus sometimes when i let my foot off the gas, the car kinda jerks.. like nothing extremely vigorous but you can feel it.. wat u reckon it could be guys?..

[ProECU]

Have either of you guys played with the throttle cable or changed injectors?

Upon de-acceleration, the ecu actually cuts the injectors. So,....
1. If you have altered the throttle cable, the TPS reading to the ECU will be magnified upon a slight release of the accelerator pedal. The ECU might be thinking its time to cut fuel.

2. Do you have replacement injectors? This is common with larger injectors, as the open/close time is increased, hence causing a lean condition, initially, unless its been tuned out.

Give us more details to help you diagnose the problem.

[SiR JDM]

thanx ProECU

ill be sure to get back to you
and the rest of u

jules i give u a call or somethin when i get some results =]

[bennjamin]

maybe JUST maybe.....if its not ECU issue - it might be mechanical - as my EG d16a8 powered lil EG hatch , has teh exact saem responses down low. I accel. slowly - fine. Accel. fast....fine....but if in any circumstance i ease off the go pedal the engine + drivetrain stutters etc. I have come to believe this is derived from my transmission ( as it also whines in every gear...soudsn oiek a dog box lol) - namely the Input Shaft Bearing which is prone to suddenly wearing out in our EG civics and whatever else .

Good luck - get a professional to check it out and let us all know !

[panda[cRx]]

i have the exact same prob in my d16a8
i also sometime get it jerking when in high revs. all of a sudden m car will jolt like i tapped the brake and tacho will go nuts for a sec. it hadn't happened in a long time but actually happened this morn on my way home :(
i also noticed sometimes when i thrash my car a lil when the tacho approaching redline it will just jump everywhere and go nuts. not a very regular thing but does sometimes happen :confused:

i'm not too stressed coz swapping ecu, engine and gearbox this month so problem should be solved (will clean injectors while at it)
but still i'd like to actually know whats wrong

[SiR JDM]

ok guys i told you ill be back..

Figured out the problem lies in a broken spring in my IAVC (Idle Air Control Valve).. and it needs to be replaced