# vr6 24v golf mk3 Bucks/Jerks/Chokes on acceleration



## thomas514 (Jan 12, 2010)

Vr6 24v 6speed 02mGearbox swap in Golf mk3

I appreciate any advice. I've had this issue for a while now...

The Problem=> When I push on the gas just a little hard the car starts to buck, it's as if the engine cuts out-comes back-cuts out-comes back-...to stop it I have to press the clutch.
I am able to bring the rpm up high if I press the gas pedal very lightly and slooowly push more n' more..

The car starts up no problem, it's stable while idling. I have no problems selecting gears. There's no funy noises coming from the engine. I have fuel.

Done everything i can think of to find the problem. 
I've pulled the engine
Replaced the Slave cylinder
Cleaned the Throttle Body
Replace the MAF
Checked all the wiring, unpluged it all and checked the terminals
Regrounded everything 
Checked all the Fuses 
Checked the Fuel pump Relay
I have Six new Ign. Coils
Replaced the sparkplugs
Got the TB Aligned

There's 2 Cels:
P0600 Serial Communication Link Malfunction 
i think this has to do with CANBUS, ( i dont have ) 
P2400 is a EVAP leak


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## RyanRaddo (Apr 10, 2007)

Was the timing chain just done on the car because it sounds like your off a tooth on timing


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## thomas514 (Jan 12, 2010)

RyanRaddo said:


> Was the timing chain just done on the car because it sounds like your off a tooth on timing


i really have no idea.-i'm gona' try and get intouch with the person i bought the engine from... thanks for the reply btw.. some ppl are also saying it could be the electronic gas pedal, or the dual mass flywheel??


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## pokey420 (Aug 26, 2005)

I had a similar issue with my 24v in 1st and 2nd at low rpms, although it doesnt sound as bad as yours. I always assumed it was the DBW gas pedal, recently got a UM flash and it has sorted out the bucking at low rpms for me. Are you on stock software?


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## thomas514 (Jan 12, 2010)

no i have unitronic software


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## thomas514 (Jan 12, 2010)

some one else thought it might be the dbw pedal also... i should find out by thursday, and ill keep this updated, thanks for replies!


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## bloody dismemberment (Feb 18, 2004)

sounds like a funking pedal, check the wiring. i know u have to cut them in half to remove them from the main harness in the car. could just be a loose splice.

even tho u have an immob flash to run the car u can still get update flashes from vw, make a friend in the shop, the service writers might not want to touch a swapped car.

also check for an air leak bucking under slight load is a common cause for a leak.


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## thomas514 (Jan 12, 2010)

bloody dismemberment said:


> i know u have to cut them in half to remove them from the main harness in the car. could just be a loose splice.
> 
> also check for an air leak bucking under slight load is a common cause for a leak.


i dont think the wiring was cut _ anywhere_ between the DWB pedal and the TPS, what makes you say they _have_ to be cut?

does an EVAP leak count in "air leak" ?

this is my first swap btw-sorry if i seem oblivious  haha 
thanks,


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## bloody dismemberment (Feb 18, 2004)

cause i have done a fair share of dbw swaps. i have found its easiest to unplug the pedal and snip the wires a foot back and then go up to the rain tray and pull the remaining gas pedal wires out. the harness is ran and often wires are ran thru it. As long as ur soldered splice is strong u never have a problem. i tried de-pining the plug but the wires do not like to sneak out of the loom with the terminal ends on there.

depending where ur leak is it could be trouble, if u n80 is good air shouldn't blow thru it and the leak would only be for an instant i guess. 

can bus codes will stay forever unless u run a mk4 cluster. 
but the evap leak code may point you to a solution.


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## thomas514 (Jan 12, 2010)

i have all mkiv wiring harness+cluster... and the DBW wire from the pedal wasn't cut so thats ruled out...


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## bloody dismemberment (Feb 18, 2004)

got ya, i guess u did the dash and everything aswell.


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## zaskar (Jan 17, 2000)

Hi there... 

I've done the swap a couple years ago, and I did'nt have that canbus code on mine, so maybe it has something to do with this. 

Did you put the abs control module? You'll need it or the engine will always cut at 4100rpm, and it do work with canbus. 

good luck!


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## thomas514 (Jan 12, 2010)

pretty sure i got the abs delete when i got the unitronic software tho..


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## zaskar (Jan 17, 2000)

good... then... do a compression test... if everything is right, i might me able to do a ride to mtl and give you a hand to solve that problem...


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## thomas514 (Jan 12, 2010)

I found something that was missed!!...I came across a thread that mentioned the intake and outake camshaft position sensors have identical harnesses .... yes, i had them reversed haha... 
I put them how they are supposed to be;
[IMG]http://www.montrealracing.com/forums/picture.php?albumid=1170&pictureid=6851[/IMG]
then turned the key-but the engine ran like CRAP..and considering how smooth the engine idled before i thought i missread the bentley or something.. i shut the engine off and checked for DTCs and there was 3 new ones:
P0300: Random missfire detected
P0302: Cylinder 2 missfire
P0303: Cylinder 3 missfire 

I dont understand why the engine ran smooth when i had the wiring reversed; and now when its hooked up right it missfires ..:sly:

btw dont thinking what i actually did was reverse them right now like a freakin idiot cause theres is no way haha ..i checked 4 times coz i it didnt seem to make much sense haha


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## thomas514 (Jan 12, 2010)

update: so i put the connectors the way they are supposed to be, took the car for a spin but the prolem is still there:thumbdown:..


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## vwmaniac16vr6 (Nov 17, 2004)

did you use the abs module with the swap? i know i had a car with issues similar to that and it wound up the abs module needed to be there for canbus to work correctly


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## thomas514 (Jan 12, 2010)

vwmaniac16vr6 said:


> did you use the abs module with the swap? i know i had a car with issues similar to that and it wound up the abs module needed to be there for canbus to work correctly


no well i had to get it chipped so they did ABS delete..


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