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General => The garage => Topic started by: Mr.Tom on 05 October 2009, 09:56

Title: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Mr.Tom on 05 October 2009, 09:56
I know there are a few threads with similar problems, but I tried what they said, and am still having troubles. Excuse my non-technical terms. I kind of know what things do, but don't know the names of them all yet :D

As the titles says, when I change gear, I get 1 or 2 small jolts or judders, then speed up fine.
I unplugged the MAF, and didn't get the problem, but it did stall when the revs dropped (3 times while I was turning in an estate, had to jump out and plug it back in to get going, embarrasing times :s )

Idle is a little lumpy too.

I took the MAF sensor block off and had a look at the wires and channel which are perfectly clean, so can see that is not the problem.

Recently also changed:
Brake servo assist hose.
Small rubber hose that looks to go from intake to injector rail? (about 6 inches of cotton braded rubber hose on right of intake)
New spark plugs (not changed the leads yet tho)

Cleaned out the black rubber pipe that goes from the top of the engine to the tube from MAF to TB, and down to the front of the engine. That was pretty gunked up.

So, could it be a faulty MAF? It's a Hitachi, but not seen many around. Looks like it fixes to the filter box differently, but if I swapped out for a Boch (which seem more readily available), would it work (with adaption to filter)?

Many thanks.
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clea
Post by: Nellie on 11 October 2009, 22:48
Hey,

Just a question cause I am not to clued up on all the jargon LOL!!! Whats "MAF" ?
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Mr.Tom on 12 October 2009, 09:31
From Wikipedia: A mass air flow sensor is used to find out the mass of air entering a fuel-injected engine. The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure. In automotive applications, air density varies with the ambient temperature and altitude, and this is an ideal application for a mass sensor.

Mine is sorted now, there was a patch of crap on it I missed :D
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: robz on 12 October 2009, 16:18
glad ya sorted it m8, sorry didnt see this thread till now :)
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Mr.Tom on 12 October 2009, 20:45
Still idling rough. Running low on ideas now :/

Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Matty-MK3 on 12 October 2009, 23:15
Cleaned the TB?
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Mr.Tom on 14 October 2009, 08:57
Yeah. Not a spot of dirt anywhere on the tb now.
Relay 30 is warm after use (was suggested before), so not faulty there.

If I put my foot down, it will accerate fine, when I lift my foot, I get a small surge of power.
Got a cheap s/h MAF that whould be here in next couple of days, so will try that too.

Only other thing I can think of at the minute is an oil change. It looks like it could do with changing anyway, so willing to give that a shot soon.
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: robz on 14 October 2009, 12:17
if i were you i think i would do all the vac pipes again, im the same position and im certain its them pal!!
may just be a small leak somewhere!!
doesnt take much!
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Len on 14 October 2009, 12:24
Checked relays?
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: robz on 14 October 2009, 12:45
hes already done that len, lol
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Len on 14 October 2009, 13:03
They dont get a mention above!  :tongue:
Title: Re: Mk3 judders when accellerating, stalls with MAF unplugged. Sensor wires clean.
Post by: Mr.Tom on 14 October 2009, 19:39
if i were you i think i would do all the vac pipes again, im the same position and im certain its them pal!!
may just be a small leak somewhere!!
doesnt take much!
I've done the one that runs from the air intake to what appears to be the injection rail (I don't know what all the parts are yet :) )
Replaced brake assist servo hose (also running from air intake)
Also cleaned out the bigger one that runs from the airbox pipe to the top of the engine, and down to the front.
Any others I should be looking for?

Have noticed that there is some exhaust escaping from the joint between the engine and downpipe. Could that cause it?