cutting out @ 4k in 5th gear

NYSpeed Automotive
1

i posted this on honda-tech and no one had a clue what i was talking about lol

my car doesnt do this all the time, only maybe once every other 2 weeks lol, but the last 2 times i have driven it, it has done it

basically when im in 5th on the highway accelerating it will almost seem to “top out” or something once i get to 4k, and it will drop down to 3500rpms, then i can drive again til 4k where it will do the same thing

right before 4k if i drop it into 4th and go to about 6k so when i shift to 5th it will be over 4k, it will run perfectly

it’s an LS motor with a GSR tranny, it’s REALLY fckn annoying lol

can anyone help?

edit: oh yeah, and when i give it gas once the RPMs are declining from 4k, there is no response from the motor or anything until i get down to 3500

2

so it doesnt do it all the time? just sometimes?

the only thing i could think of is a rev-limiter sort of thing. i know my car cuts at 5k in 5th, but thats the computer doing that. not 100% sure what is causing your if it doesnt do it all the time.

definitely sounds like an ecm problem though. thats just my $.02.

3

that’s what i was thinking, but i can go to 7k in 4th (which is a lot faster than 4k in 5th) and it’s fine

actually… the only thing i can think of is my speedo is fucked up because the wiring for my vss is somehow shorting and isnt giving a read, so im wondering if that is causing the car to think that it is topping out, because the speedo will be wacky sometimes

but ive topped out a car before and it would just stay at that rpm and now drop down like what my car is doing, who knows

im thinking it may be realated to my speed sensor…

4

hmmmmm. so it hasnt done this in 5th gear before? i can redline my car in any gear i want except 5th (not that i like to, i have enough problems lol), then it cuts out at 5k, but only in 5th.

i would check the sensors like you said, that’ll be your best bet.

5

yeah i have to splice in a new plug for the vss because mine’s all corroded and poopy, but i dont really know how lol, so im taking it to swerve sometime hopefully

6

splicing is always a fun time. i got to get up close and personal with my PCM when installing the safcII multiple times, all because i had a vafc harness and a few wires were switched lol.

just make sure you splice, solder, and heat shrink everything.

good luck with it man

7

pull the module and take it to advance it might be bad…??

8

honestly this has been happening to me lately too. what is it! it sometimes does it when i’m in other gears too though. and i can not get up to speed fast from red lights and shit. like… it’s choking.

9

do you have launch control?

If so check VSS. My boosted honda used to do that…

10

na it’s a completely stock car, it used to be boosted i believe, but i think they were using a p72, i have a p06 now; im pretty sure everything was changed back to stock

ill have to check when i go out later

11

your using a stock p06 on an ls???

vss would not have anything to do with a completely stock motor/ecu especially one w/o vtec

i would be willing to bet since its rpm related it is something in your distributor going out and the extra stress from the load and rpm is causing it to not be able to put enough power to move the car

switch dizzy’s with another friend and see if it still does it

12

p75 my bad :slight_smile:

ill check the dizzy thank you

13

Used to happen to me in my old turbo honda, it was the VSS.

14

Is your check engine light on?? It may be cutting out because of that…I remember you telling me that your check engine would go on occasionally due to the vss. And if thats the case im def thinking THAT has something to do with it…

15

sounds like vss issues, not rev limiter/rev related

16

as far as i know, on non-vtec motors the vss does not control anything, whereas on a vtec motor the vss is needed for it to engage

i just dont see how with a non-vtec it could be the vss although it is a possibility

17

okie

so today it does it again, im like arghhhh, then i realize i can record it with my phone, and show you, so im like yayyy

so i go threw the tollbooths, have to slow down, downshift etc etc
i rip threw the gears with my mad fast non vtec yo, get up to 4k and it doesnt do it :picard: :picard:

idk why, but when i downshift to like 2nd, and then go back to 5th it wont do it, but it will do it if i downshift to 3rd/4th it will

anyways, since i couldnt actually get the car to do it, i recorded it and did a simulation, any one know how to upload video from a phone? i also recorded my fucked up speedo

18

it seems that it is speed specific. The ECU doesn’t have any way to know that you are in 5th gear. That means that the only other piece of evidence here, is that 5th gear @ 4k = some speed.

So, you should check all the components that feed speed to your ECU. Start with the VSS, work your way toward to the ECU from there.

19

the ecu does not use speed as a reference for anything except vtec

i think it has more to do with load than anything

20

yeah my car would sometimes do that because of the launch control, it would hit rev limiter at like 5000rpm and id have to shift