abf digi 3.2-suspected h/g causing bad idle. fixed now back with a vengeance

abf stutter. it was all going so well....

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since putting the abf in the mk2, running digi 3.2, iv had a few niggles. but they were from day one. a new one has made itself known!

it had stutter at 3k to start with, but a change to the abf relay and new vacume pipes solved that.

now i have a stutter from cold. it will idle perfectly, then after 15 seconds start to stutter. the last 3 journeys. the car idles ok, but just wont pick up in gear. it felt exactly the same as when i ran out of petrol a few weeks ago. or, its a few teeth out on the timing. which its not! give it 400 metres or so and it'll sort itself out, then its perfect! its no where near like up to temperature though.

its a **** as i wanted to get all the niggles out the way before the soon impending all stage head and re-map.

any ideas fellas?

*UPDATE*

ok, so the car has done this from warm now. 80' oil temp. and the car also does idle like a bag of spanners. but doesnt show on the rev counter. its the first time iv noticed that i have a front solid mount!
i picked up a new no'30 relay today, and im currently resetting the ecu. no changes.
when in gear pulling, it really boggs down. no power like its retarding. pull over, give it a few clean revs, and it clears. and the cars perfect!

 

do you mean it only does it when not up to temp?

 

its done it from warm now.

 

although my car was on the rr last wek and proved to be healthy, im going to pick up a voltmeter and check the resistance of the sensors, and power to loom.
is there a page with all the values and ranges?

 

original post updated.
its not temperature dependant, just the first few hundred metres after the ignitions turned. it has rough idle. but doesnt show through the rev counter. and really boggs down. shakes, judders give it some clean revs and it clears out and is perfect.

 

so this is still a problem. i had it on vag-com and the measuring blocks checked. no problems there! we thought it may of been the coil breaking down, 40 wasted! theres only the isv left!

 

Have you checked the plug leads matey.

 

plugs and leads were new when the engine went in. 2k miles ago.beru and ngk items. il whip out the plugs too see what colour they are.

 

Mine does exactly the same as yours, wont idle when first started then drive a few hundred meters up the road and feels like its gonna die then kicks into life and idles fine. Im going to try adjusting my throttle body and TPS and then replace ISV and throttle body if this doesnt fix the problem.

 

there must be a logical explanation! im going to check the plugs tomorrow

 

Sounds like and ignition problem. As the weather gets colderand damper, coil, plug leads etc can play up if the insulation is failing.

 

all ignition parts are new.cap, dizzy, leads, plugs, coil. all oe beru items
im up early so il look for any arcing of the leads in the dark.

i did spill $hit loads of oil over the cam cover last month, obviously down the plug holes. but this seems to of burnt off with no damage to the leads.

i was also hoping for a crack or oil leak into the dizzy. no luck either.
in every instance, the idle is not as smooth as it once was.
when the lump first went in i was amazed at how well it idled. quiet. hence why i thought a solid mount would be acceptable.

im also going to check the timing. although again, all new with auto tensioner

 

Have you cleaned the ISV?

 

the isv wouldn't cause the hesitency whlist driving though. is the TPS connections corroded?

 

Was thinking about the idle.

 

tps wiring is all new. and i had 2000 trouble free miles before this started. midland vw checked all measuring blocks on vag.com. i assumed he checked tps operation.
a throbbing idle is what i would describe it as. really shaking the car.

 

I know its a new coil. but have you checked its resistance? Before i bought my mk3. The previous owner changed everthing coil, plugs etc. It had a bad starting problem and hesitancy problem. After checking and changing all the obvious things. Relays, vacuum lines. Still had problem. Measure coil resitance and it was outside tolerance. Changed it and it was cured.
Mine was intermittent, Check earths also. Problem with diagnostics on the abf's is. It don't tell you much. Down to old fashioned fault finding.

 

so i tested my abf coils today. one a 12 year old vw item, the other a week old beru gsf item.

vw pin 15-1 0.8ohms pin 15-ht 3.6ohms
beru pin 15-1 0.7ohms pin 15-ht 3.2ohms

oh, so the 12 year old item is in better condition. cheers gsf!

 

i unplugged the isv while running and the only thinng that seems to happen is my revs now fall like a stone. instead of hanging @2k, then 1200rpm. the car starts well with the isv disconnected too. its definately working though as you can hear it pumping air through the airbox.

danny_p also suggested the cam impulse sensor. on the dizzy. i disconnected this and nothing happened. at all. just kept idling rough and throbbing!