Mp9 Throttle body Issues

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Hir
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Mp9 Throttle body Issues

Post by Hir »

Hi guys, I tried to search about the problem i am having but could not get all info.

i need Advice on what to do? So here is my problem...
Converted my caddy Mk1 from carb to 2L FI, running mp9 control box (chipped and decoded). The problem is the bakkie does not idle and it splatters, missfires, Jerks and no power, almost like its starving for fuel. The strange thing is when i remove the plug from the Throttle body (tps sensor) it idles fine and revs up fine (i haven't driven it like this yet, not sure if i should). When switching the Ignition on, the throttle body does not move or open but make a buzzing sound.

I have removed the throttle body cleaned it nicely but still the same problem.

What could be the problem? i have replaced the 4 pin temp sensor also.

Guys all your advice will be much appreciated.

Thanks
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Hir
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Re: Mp9 Throttle body Issues

Post by Hir »

Update : Replaced the throttle body today and still the same problem. Stripped the wiring from the box to the tps plug and all corresponds but the thing i noticed was that pin 2 from the ecu plug was bridged with pin 1 on the ecu plug and going to pin 1 on the tps plug. Is this correct? The harness is a shortened harness that was made up for me.
Baldwin02002
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Re: Mp9 Throttle body Issues

Post by Baldwin02002 »

Hi, did you come right?
Current:
Mk2 GTS 1.8 --> 2.0 16v MP9 --> Soon to be 2.1 16v MP9 with Throttles
S3 2003 BAM --> Stage 1 with full Exhaust
S4 2004 --> Stock
A3 2010 1.8T Cabrio --> Stock
//////
Previous
Golf Citi 2.0 8v MP9 2007
Jetta 4 V5 10V
Honda CB400 '74
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Hir
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Re: Mp9 Throttle body Issues

Post by Hir »

Hi. No i didnt im still battling...
Baldwin02002
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Re: Mp9 Throttle body Issues

Post by Baldwin02002 »

Pm me your email address I will send you a wiring diagram. Trace the cables from the ECU pin. When done do throttle adaptation. If there is an error during adaptaion. Replace a throttle body. Does it make a "wiiiiiiiiiii" sound when you put the ignition on?
Current:
Mk2 GTS 1.8 --> 2.0 16v MP9 --> Soon to be 2.1 16v MP9 with Throttles
S3 2003 BAM --> Stage 1 with full Exhaust
S4 2004 --> Stock
A3 2010 1.8T Cabrio --> Stock
//////
Previous
Golf Citi 2.0 8v MP9 2007
Jetta 4 V5 10V
Honda CB400 '74
Torker
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Re: Mp9 Throttle body Issues

Post by Torker »

Try tracing the wires according to the pin-out attached:

Image
Current rides:

VW Golf - 83 GT 2.1 16V 2-door with throttles
VW Golf - 78 LS 2.0 8V 4-door (2.1 ABF with throttles in progress)
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Hir
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Re: Mp9 Throttle body Issues

Post by Hir »

Hi. Thanks guys @baldwin @Torker. Much appreciated

All the wires r 100%. Sorted out the misfire , one injector wire was broken.

The problem I'm having now is the car doesnt idle. I have to keep the revs up or else she dies... and its very heavy on fuel . I can smell like its running too rich, spark plugs have thick black dust on them. Not sure wats causing this.

b4 i 4get to mention, i cant get the ecu diagnosed or set throttle adaptation bcos im running a shortened harness and it doesn't have the obdll connection.
Maponya1998
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Re: Mp9 Throttle body Issue

Post by Maponya1998 »

Guys i'm having a problem here my golf 1 is failing to start as i think it failing.to open the injectors and the throttle as well if i switch the ignition on its quiet that wiiiiiii sound is not thr although the car has spark plz help
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vandyh
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Re: Mp9 Throttle body Issues

Post by vandyh »

have you tried to swap out the ECU, just to test it?
The servo motor in the TB is controlled by the ECU.
is there power on the TB pin1 on ignition on?
Current ride
2007 - Jetta VI 2.0TDI
2007 - Velociti - 2.0 (91wkW, 174nm) @ 8V Performance
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Slammdlarry
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Re: Mp9 Throttle body Issues

Post by Slammdlarry »

Hi,I’m having the same issue,my car does not want to start,my TB does not make the wiiiii sound it used to when I switch on the ignition,if i kick start it it has a misfire in the beginning but then after reving up once or twice it sounds normal but overfueling a lot,once i remove my foot from the pedal it dies,it doesn’t idle if I don’t have my foot on the pedal,and idea as to what it could be?
Ashveer03
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Re: Mp9 Throttle body Issues

Post by Ashveer03 »

Slammdlarry wrote:Hi,I’m having the same issue,my car does not want to start,my TB does not make the wiiiii sound it used to when I switch on the ignition,if i kick start it it has a misfire in the beginning but then after reving up once or twice it sounds normal but overfueling a lot,once i remove my foot from the pedal it dies,it doesn’t idle if I don’t have my foot on the pedal,and idea as to what it could be?
Possibly a dead throttlebody..?
The idle is control via the steppermotor inside the throttlebody, so if the tb is not working, the car wont idle.

Doesnt explain the no start with the key though, if u press on the accelerator pedal while starting the car should start

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When a car tailgates me, i slow down - then floor it and give them a cloud of diesel smoke to choke on :driving:
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Re: Mp9 Throttle body Issues

Post by Slammdlarry »

When i do put my foot on the pedal yoi can hear it is about to start but just doesn’t get going,i replaced my throttlebody but still nothing.when i block off the breather pipe coming from the tapped cover it starts
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Re: Mp9 Throttle body Issues

Post by panic-mechanic »

None of that makes any sense. There is nothing that a breather does that should make a car run or not unless it virtually has no compression and blocking the breather adds some.
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VAG Fan
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Re: Mp9 Throttle body Issues

Post by VAG Fan »

Does the breather enter the intake duct after the throttle? If so, then this means that the breather is under vacuum and needs to be leak-free for the engine to run properly.

IMHO the symptoms point to a massive vacuum leak in the breather, introducing unmetered air, hence the no-start.
Mark R.
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Re: Mp9 Throttle body Issues

Post by panic-mechanic »

MP9 is manifold pressure based - not metered air. There is no airflow meter.
No mp9 breather ever goes after the throttle. It is always Pre TB.
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Re: Mp9 Throttle body Issues

Post by VAG Fan »

There goes my theory...
Thanks for the explanation.
Mark R.
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2004 VW Golf TDI, type 1J, AHF, 317k (2016-current) --- daily
1990 VW Fox, type 16, HM, 304k (2005-current) --- spare runaround
Previous:
1992 Audi 500 SE, type C4, AAR (2001-2020) --- nice while it lasted
1983 VW Golf GTS, type 17, FR (1992-2005) --- most fun car I've ever had
1978 Audi 100 GLS 5E, type 43, WC (1991-92) --- died in the side of a Rekord who cut me off
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Re: Mp9 Throttle body Issues

Post by panic-mechanic »

See why it makes no sense
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VAG Fan
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Re: Mp9 Throttle body Issues

Post by VAG Fan »

Yes.

BUT:
Are we certain that the two posters who joined this thread late (Maponya and specifically slammdlarry) actually have cars with MP9?
Mark R.
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2004 VW Golf TDI, type 1J, AHF, 317k (2016-current) --- daily
1990 VW Fox, type 16, HM, 304k (2005-current) --- spare runaround
Previous:
1992 Audi 500 SE, type C4, AAR (2001-2020) --- nice while it lasted
1983 VW Golf GTS, type 17, FR (1992-2005) --- most fun car I've ever had
1978 Audi 100 GLS 5E, type 43, WC (1991-92) --- died in the side of a Rekord who cut me off
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Re: Mp9 Throttle body Issues

Post by panic-mechanic »

Well if they don't then what on earth are they doing here.
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'09 Touareg 3l TDI
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Re: Mp9 Throttle body Issues

Post by Slammdlarry »

Vw mk1 velociti,definitely mp9 guys,,the breather goes into the induction before the tb,i changed my temp sender and the car starts,the only problem I’m having now is that it does not idle in cold start..it only starts idling by itself when it gets a bit hot?normaly on cold start my revs would be above 1000rpm but now i need to manually keep it there as if I’m driving a carburetor golf
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Re: Mp9 Throttle body Issues

Post by panic-mechanic »

Do anthrottle body calibration and see if it is still alive. Does the tb move when you switch the car on?
Stephan van Tonder - Jhb - Putfontein Benoni
'05 Audi A6 3.0L TDI Avant
'09 Touareg 3l TDI
'13 VW CC 2l tdi (repair project)
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Perfect Power dealer. I do dyno tuning.
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Re: Mp9 Throttle body Issues

Post by Slammdlarry »

It doesn’t move or make the noise it used to make,i got another tb and still no sound or movement on the tb
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Re: Mp9 Throttle body Issues

Post by Slammdlarry »

I tested my tb on a friends car and it makes the sound and movement when he puts on his ignition
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Re: Mp9 Throttle body Issues

Post by panic-mechanic »

then you have a management box issue.
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Re: Mp9 Throttle body Issues

Post by Smod »

My golf mpi, car refuses to start, it stalled like no spark l, there is fuel, it just swings and doesn't turn over, when I leave the key on, the tachometer jumps and so does the throttle, help what could be my problem
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