Throttle body

[mfp4073]

Has anybody replaced the throttle body on an LS 1 05 Monaro. MF don't list them so I think it might be a pain to find one.
I think throttle may be the cause of the surging.
No fault codes showed up on a diagnostic, but a knock sensor was detected doing it's thing, so I guess the timing is being retarded for some reason.Hence the surge?
Is it possible that the Wortec remap I had done a while ago needs looking at?

Ideas welcome.

Regards John

[ringram]

Try unplugging the maf and see if the surge goes.
It will zero the intake temp out but remove any issues with the maf from airflow calcs.

Is this an electronic throttle LS1?

Whats the symptoms? If it was fine before I doubt you need to look at the tune.

Something probably physically changed or broken.

[mfp4073]

ringram said:

Try unplugging the maf and see if the surge goes.
It will zero the intake temp out but remove any issues with the maf from airflow calcs.

Is this an electronic throttle LS1?

Whats the symptoms? If it was fine before I doubt you need to look at the tune.

Something probably physically changed or broken.

I have already unplugged the MAf sensor and the problem was still there.
The car is an electronic drive by wire LS1 Monaro 5.7 VZ, so I was thinking maybe the throttle position sensor was at fault.
I was wondering if a car is mapped do the re-maps degrade over time and need to be tuned again?
The basic symptoms are a slight surging on light throttle throughout the rev range hot or cold. Also sometimes the revs are slow to return to idle when you stop at a junction.
The checks made through the diagnostic test show all to be in order, other than a active knock sensor. So either the Knock sensors are at fault or something is causing the knock sensors to dial back the timing.
Maybe at the end of the day a job for MF.

Regards John






Regards John

[ringram]

Tunes dont usually degrade, though they can "learn" you can reset it by pulling the PCM fuse for a minute or two.
Could also be O2 sensor gone wonky.

Try PCM reset first. Then a trip to the fish sounds your best bet if you are getting no codes.

[motomk]

There are some new ones on Ebay (Oz flavour and US flavour) but maybe visit Mr Fish first in case it is not that.
From a picture I am looking at there might be a part number on the side of it, at the top, on the right hand side as you look at the engine from the front of the car near where it bolts into the intake manifold.

[mfp4073]

I did pull the PCM fuse and the car did run a lot smoother. The surge was still there but not as bad. I had to do a bit of start stop town driving today and it did feel better.
So not a simple cure but worth a try.
I think a full diagnostic check which can get right into the system this time is in order.

Thanks to all....

Regards John

[anonymous-user]

mfp4073 said:

The surge was still there but not as bad.

When you say "surge" what do you mean? Does it not idle?

I have an VZ CV8, same as you with a 102mm PWR ETC throttle body. It does struggle to idle smoothly with the AC running but I put it down to the cam, I quite like the character it adds!

[KMud]

wormus said:

When you say "surge" what do you mean? Does it not idle?

I have an VZ CV8, same as you with a 102mm PWR ETC throttle body. It does struggle to idle smoothly with the AC running but I put it down to the cam, I quite like the character it adds!

There's a separate setting for idle speed with the AC on, sounds like yours would benefit from being higher. It's a column actually, a function of engine coolant temperature.

[anonymous-user]

KMud said:

There's a separate setting for idle speed with the AC on, sounds like yours would benefit from being higher. It's a column actually, a function of engine coolant temperature.

Thanks. The problem is the AC clutch kicks in and out making the revs fluctuate, eventually it does even out.

[SturdyHSV]

wormus said:

Thanks. The problem is the AC clutch kicks in and out making the revs fluctuate, eventually it does even out.

It's odd that it kicks in and out, there are also a wide array of settings for controlling the AC clutch including how quickly it can come back on after it's gone off and things like that. I totally understand you liking the character it gives though

[mfp4073]

wormus said:

When you say "surge" what do you mean? Does it not idle?

I have an VZ CV8, same as you with a 102mm PWR ETC throttle body. It does struggle to idle smoothly with the AC running but I put it down to the cam, I quite like the character it adds!

My car idles fine without a problem, but it has a slight surge when you lift off the throttle. Also an engine knock sensor has been dialing back the timing.

Regards John

[V88Dicky]

I think mine does the same as yours occasionally, John. Usually when it's cold and hasn't been out for a while.

Revs go up slightly when you're on and off the clutch at slow speeds?

Soon returns to normal though.

[KMud]

V88Dicky said:

I think mine does the same as yours occasionally, John. Usually when it's cold and hasn't been out for a while.

Revs go up slightly when you're on and off the clutch at slow speeds?

Soon returns to normal though.

That sounds like normal behaviour - IIRC the default speed threshold for transition to idle is 2 mph, above that it will float slightly higher.

[V88Dicky]

Every day's a school day!