help i have a problem with my zed

 

i have a 1990 Z32 swb non-turbo..ok the car is good through out apart from one small issue.

 

when im cruising along at any given speed and i have my foot just resting on the accelerator..it dicks about slighty... it is when im trying to just cruise at about 30 or so and im maybe slowing down but i stil have some throttle....

 

it seems to varry the power..jerks around a bit (although not agressively)

 

it idles fine...and if you just crack the thottle the revs lift and it seems steady...just when im travelling it dicks about?

 

how do i cure this?

 

any help would be cool.

Sounds to me like a nackered O2 sensor.

 

When cruising they constantly give readings to the ecu so it can adjust the mixture.

When flooring it the ecu just uses fuel maps and ignores the O2's.

When ticking over it also just uses fuel maps.

 

Try running an ecu diagnostic, may tell you if a sensors nackered.

http://www.ttzd.com/tech/diagnostictech.html

or http://www.twinturbo.net/ttnetfaq/FAQpages/ECUdiagnostics.html

Hi there.

 

Mine used to do this with a dodgy TPS sensor connection. It used to show up on my AVC-R under the TPS voltage, the % throttle didn't really show this. (if you have one!). Clean the TPS connectors even if they look clean, even disconnecting and reconnecting can sometimes help.

ok i will try the tps first...one thing im wondering is is it only the connectors that i can clean..is it ajustable..if so how do i do it and if i take it off does it need to be recalibrated can i clean the internals and so on?

Mine does exactly the same thing, around 2000rpm particularly and I know I've got a duff O2 sensor.

Mine does a similar thing sometimes, and i know i've got 2 duff O2 sensors :D

If you disconnect your 02 sensors they will default at 0.33v and should eliminate the problem, however this is no way a long term solution and they require changing as soon as possible.

 

Get someone near to you run a diag on it with a conZult.

ok firstly thanks for all your advice...

 

ok this is what i have done...i run the LED test on the ecu and everything came back fine (code 55) even the O2 sensers test was ok on both sides...

 

i tested the voltage on the TPS and it was 0.44 so i altered this around first trying 0.5 then trying 0.4

made little difference to my problem.

 

it is only slightly jerky..and only on the slightless throttle setting

 

cruising at high speeds is ok as requires more gas i suppose?

 

i even dissconneted the o2 sensers as advised but it made no dif..so i reconected them

 

i havent had my car more than a few months..it has after market rear exhaust section and a K+N sir filter..it is a non-turbo.

 

i have a suspision that the problem seems to be worse on the coldest days?

 

any more ideas?:confused:

im thinking of getting a consult..but im not sure how to use it or whether is would diagnose my problem...

 

hellllllllllllllpp