STILL not idleing right, loosing the will now!!!!!

ok, so story goes, my 91 8v digi PB sat still virtually from november till march, started it a couple of times but thats it. came to use it properly again in march and the idle was a bit lump, it steadly got worse. discovered that the headgasket was on its way and thermostat was sticking a bit, so hear is a list of things i've done, and still it not quite right

- replaced all gaskets (head, inlet, exhaust, TB-manifold, rocker, rocker bung for breather)

- had head skimed and port and polished by Vagobonds

- all filters replaced including fuel filter

- all new hoses for silicone ones

- thermostate replaced

- new water flanges on front and side of head

- new plugs

- new leads

- new rota and dizzy cap

- thouroughly cleaned the ISV, breather dougnut, TB inlet manifold, AFM.

- new expansion tank and new blue cap

- new oil cap

- replaced all the vac lines, two at front(one blanked off one to Fuel pressure thing) one at rear of inlet, blanked off, one on brake servo thing on right of inlet.

- new battery


i think that that is it, prob something missing, but i truely am out of ideas as to what it is.

i set it up as per Rubjonnys guide, got it to sit at 850-900 and CO2to 1.8 consistently. timing is right etc, but it just doesn't sound very smooth, like the exhaust note isn't smooth, and it just doesn't sound right.

i took it to a garage, and they rekoned it was fine, but it has been smoother than this before!!!

 

you wanna sell it? only joking
(do ya ?)

tried checking out all the engine bay wiring/earths/sensors?
is the static timing definately right(not 180deg out?)
belts all moving round?

 

yeah timming is definately right, it was right before i layed it up for winter and then when i started it up again it was ok, and then it just got rough. and then this weekend when i put it back together i checked it so many times, its definately right!

i might have to sell it if it keeps spending my money, (it'll never happen)........

 

so was it running fine before it was parked up?
if so maybe moisture,inertia, dead fuel could be affecting it?

oilways and waterways are good? not contaminated due to HG?

dont really know what to suggest other than to go through each system in turn
fuel
water
electrics

and check everything. (but sounds like you've already done that)
feel for ya, must be hurting your brain. if you crack it post up the fault

 

well, it has gone through a full tank before i took it all apart and put fresh petrol in it.

all the fluids were replaced this weekend, and i cant think what electrics can affect it that i havent checked.

what does the knock sensor do, and would it have an affect? any other sensors that might be to blame, all the MFA reads out fine

 

Throttle body switches not stuck open?

Neil.

 

Have you checked the injectors?

 

If it just sounds different from what you'd expect, that doesn't mean it's got a problem. You've just changed the flow characteristics of the cylinder head by having it ported.

Drive it for a few days and see how it feels. See what MPG it does, and how the temperature sits.

If it drives and idles smoothly, chances are it's fine.

 

i think if the knock sensor is u/s, not torqued correctly it can cause probs. but would sat for a few months cause this?

 

what about temp sender.(blue one ) or dodge earth.

 

it was sounding different before i had the headwork done

the throttle switch is ok.

i have a blue temp switch on order from vag today, and the black one that sits infront of it, they should be here on weds. do i have to do the engine setup again if i replace the switch, of should all be fine if i have set it up correct.

how can i best check the injectors?

 

Not too sure how to check the injectors on your Digi setup?..... I had a rough idle on my k-jet & could'nt work out why it was so lumpy. Replaced quite a few parts & verified the fuel & electrical system was fine with multimeter. Did a simple diagnoses by pulling off spark plug leads one at a time on idle & found one cylinder was not firing. Spark was good, the head had been redone, timing perfect & established faulty injector by placing it in a jam jar (jam removed) and checking for spray - or lack off in my case.....

 

Digi injectors hardly ever go wrong. If it idles at about 900 rpm and doesn't hunt up and down, it's probably ok. Drive it for a bit to see what MPG it does, and keep an eye on the gauges.

One more thing... did you clean out the breather pipes when you did the canister on the rocker cover?

 

i replaced them, so they brand new

 

Then drive it for a week (fairly gently) and give it a chance to settle down. If the valve guides have been changed you should run it in for a few hundred miles anyway.

 

i'm just a bit worried that it is looking like a fueling or electrical problem, niether of which i know very much about, and are prob the most expensive to fix!

 

If it's got a spark and runs properly, it hasn't got a major electrical problem (with the possible exception of an intermittent hall sender/coil problem).

If it's got a fuelling problem, the CO readout wouldn't be 1.8 %

Drive it, but be sensible, especially when it's cold. Watch the gauges, keep an eye on the oil level, and stop if you get any warning lights.

 

do you think it would be worth putting a bottle of redex type stuff in? see if that helps matters?

 

No - it's crap

 

ok, so have made an observation thiseve, not sure if it is at all relevent

the red LED with the battery simbol above it on the dash, after i start the engine, stay on, untill i rev the engine, then it goes out.

then when i got back i turned the light out and notived that that LED was very very dully flickering at idle???

any significance

the battery is brand new and fully charged, the alternator is providing ample ampage.....