The 2.4l Throttle Body thread

Ffoeg

Just noticed that I'm mentioned in this thread :shock:

When the 2.0SC TB first went on it did run a bit erratic, mainly the tickover was around 2.5-3.0K, but over time it settled back down to where it should be. I assume this was due to the TPS just opening the buttefly the same angle as the OE TB, and giving the enigne too much air, so the ECU reacted and dumped fuel in accordingly. It seems that the ECU just sorted it out after a few miles

The only real issue I still have is that when I first start it up from cold, the revs shoot up to about 2k for about 5 secs then drop down. No real biggy as far as I'm concerned.

and Adam, how dare you call my engine "virtually standard" 🙂

slimvince

Mark - what are you using for controlling the throttle in the vids? A custom made circuit or are you using an original ECU to control it? My plans include using the original ECU for handling the rev-counter, speedo, tacho etc and a standalone ECU for controlling ignition and fuel. Have not decided if I should go cable-throttle, let the orig ECU manipulate the throttle, or build some custom circuitry to drive the throttle or...

markv said:
Haven't tried changing anything yet. But I did do a test with the ECU to see if there really might be a positioning problem. But I can't find anything. If I check the commanded and sensed values for both throttlebodies they all look fine.

I really stand by my first diagnosis that this is a problem due to the failsafe mechanism in the ECU that is geared for the flow of a standard 2.2 TB. And a well ported or 2.4 TB just gives problems.

So you can see the positioning for yourself:

2.4 throttlebody:

https://www.youtube.com/watch?v=0TDMo-AQA44

2.2 (ported) throttlebody:

https://www.youtube.com/watch?v=1ev29be0Vyk

The main difference I see is the larger opening the 2.4 TB gives, but both reach their maximum, it is just a TB design point.

Mark

Lightning_Coupe

Ffoeg said:

and Adam, how dare you call my engine "virtually standard" 🙂

:lol: I didnt mean it like that that buddy. What I was getting at was at the time you fitted the 68mmTB you where running a standard intake and exhaust manifold, no cylinder porting, and I might be wrong, but did you have the standard cams in aswell. I know you have since upgradded it all, but when you first did the TB mod it was a fairly standard engine perhaps minus the cams if they were already in, and it ran ok, blowing out the theory that you needed a havily modified engine for the TB to work without an eml. 😃

Ffoeg

🙂

Yeah - I just had just put the cams in. but never really ran the car much till I'd got my BFO induction sorted

If you call wafting a dremel over the manifold "ported" then I spose I did that too, when the TB went on.

markv

slimvince said:
Mark - what are you using for controlling the throttle in the vids? A custom made circuit or are you using an original ECU to control it?

I'm using a potmeter with some resistors. Basically the same as the original throttle pedal.

Mark

slimvince

markv said:

slimvince said:
Mark - what are you using for controlling the throttle in the vids? A custom made circuit or are you using an original ECU to control it?

I'm using a potmeter with some resistors. Basically the same as the original throttle pedal.

Mark

ok, some pots + ecu + throttle then

Would be good to know how much intelligence the ECU puts between the pedal and the throttle. I do not have any log at the moment from my obdii-interface, but iirc you can log the throttle position but not the pedal position? If both could be logged one could analyze if the ECU simply just opens the throttle in proportion to the pedal sensor signal, or if it does anything more sophisticated.

markv

It is more sophisticated then that. From what I've felt when driving it depends at least on RPM's you are doing already. Probably emissions thing, if you open the actual throttle more slowly you probably get better emissions.

And you are correct that with the standard OBDII parameters you can not log the pedal position, only the throttle position. And if you would be able to log both with two seperate command's it will probably not do much good, because there would be a time delay between the two commands, which would skew the results you are looking for.

Mark

Alessio

Any good news about "box of tricks"?

Sjdickso

Alessio said:
Any good news about "box of tricks"?

Have a look at this tread

https://z22se.co.uk/viewtopic.php?t=8324

Alessio

Sjdickso said:

Alessio said:
Any good news about "box of tricks"?

Have a look at this tread

https://z22se.co.uk/viewtopic.php?t=8324

Thanks! I missed it :cry:

slimvince

markv said:
It is more sophisticated then that. From what I've felt when driving it depends at least on RPM's you are doing already. Probably emissions thing, if you open the actual throttle more slowly you probably get better emissions.

And you are correct that with the standard OBDII parameters you can not log the pedal position, only the throttle position. And if you would be able to log both with two seperate command's it will probably not do much good, because there would be a time delay between the two commands, which would skew the results you are looking for.

Mark

Just had a look at what the throttle does when I operate it (using the accelerator pedal) in the car, the engine not running. It exhibits the same "slow" opening speed as in Mark's vids. Closing goes VERY much faster than opening.

I wonder 1) why it opens so slowly 2) if it always opens that slowly or only under certain circumstances (cold engine, when the ECU recognizes the engine isn´t actually running or cranking or if it would depend on rpm?).

If it always opens that slowly - wouldn't that have a negative effect on throttle response?

vocky

it only opens slowly when the engine isn't running, not sure why notsure.gif

markv

You can make it open VERY fast by sending the direct positioning OBD commands to it. 0% to 100% in a fraction of a second 🙂

Mark

Muncher83

I just got the P1514 error code on mine with a ported 58mm throttle body :/

The car felt kind of weird, went a bit noisey, restarted it and although the MIL light was on and the code logged, it seemed to behave normally. :?

markv

That sounds familiar..

So basically this means you did an excelent porting job 😃

Mark

slimvince

vocky said:

'open + closed' throttle positions
pin numbers on tb plug

A-G = add none
2.0- 4.45 + 2.67 (reversed)
2.2- 4.12 + 2.23
2.4- 3.82 + 1.91

A-C = add 360 ohms to wire C
2.0- 1.96 + 3.71 (reversed)
2.2- 3.20 + 5.10
2.4- 2.64 + 4.55

D-H = add none
2.0- 2.67 + 1.51 (reversed)
2.2- 2.36 + 1.15
2.4- 2.19 + 0.98

D-B = add 240 ohms to wire B
2.0- 1.04 + 2.21 (reversed)
2.2- 1.77 + 2.97
2.4- 1.44 + 2.66

Just read this again...
Some Q:s:

The resistance you measured and specified above are in kOhms -> the difference is then in ohms (the resistors that needs adding)?
I guess that the pinlayout for the two pots is:
pot 1: A connects to the sliding wiper and G and C to each end of the semicircular resistive surface?
pot 2: D connects to the sliding wiper and H and B to each end of the semicircular resistive surface?
Should not then the resistors needed be
300 ohm to G?
550 ohm to C?
170 ohm to H?
330 ohm to B?
(nothing to A and D)
dunno..
Hopefully then the feedback to ECU on throttle position would be much closer to the 2.2 TB - and that would cure the P1514, unless we actually need to fool the ECU that the throttle is more open than it actually is because the 2.4 TB flows more air at almost every throttle position...

vocky

update;

I heard a little rumour that the 2.4 tb is currently being mapped, I will update as and when spy.gif

Alessio

vocky said:
update;

I heard a little rumour that the 2.4 tb is currently being mapped

Really? That is a good news drool.gif

I have both TBs (68mm and 65mm), but did mount no one yet... :?

rushy

vocky said:
update;

I heard a little rumour that the 2.4 tb is currently being mapped, I will update as and when spy.gif

Great, who do we call? tel..

blue_se2

Ghost Busters lol

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