Problems with power

Changed the blue one and engine runs perfectly after that Thank you for all of you !

Well this is starting to sound a lot like, dear diary today my golf… so the problem came back, but its not so bad but still it is. So now when i start the motor it goes like rocket for a while or sometimes it might not, reving motor in cold usually doesnt drop then the rpm to really low. But after driving a while the power disappears a bit and when throttling the acceleration feels like jumping, just like the engine would be coughing a bit. When it does that i stop the car and turn it off and usually when i start it again it will run perfectly, for a while.. Any ideas ?? I am checking the grounds but they seem like OK.

Could distributor cap and rotor cause this ? I have cleaned them but they seem to be very old..

Checking the grounds isn't a good thing, you might feel better about yourself, but cleaning them and verifying with a meter that you have 0 ohms resistance is the better thing, replacing your main battery to frame and frame to engine/tranny goes a long long way to better motoring.

A bad cap can cause this type of thing, but validating that your timing is spot on, and that you have now vacuum leaks is better.  Don't forget on a Digi that you have a idle air bypass screw on the back side of the throttle body against the firewall.  If you can turn that 7mm screw with your hands, then the o-ring is CA-CA-d00d00 and needs to be replaced.  Going back count the turns you take to remove it.  Write that number down, then replace the o-ring and wrap the threads and only the threads of that screw with Teflon tape.

You might want to unplug your o2 sensor if equipped and see if it doesn't run a tad better, It will run in limp or enriched mode, mileage will suffer a wee bit but can go a ways to tell you.

1st set the time.

have you checked thru everythign in my guide? problems with the idle are often idle switch issue or wiring to it, have a listen for the noise the main pump is making when it starts playinmg up as well, if it gets louder this could be an indicatiuon the lifter in the tank is failing.

if you suspect the ignition components then just get new, they are not expensive, oem beru parts can be had here:
AVS Car Parts - [The VW - Audi - Seat - Skoda Parts Specialist]

have a good look at the filler neck make sure its not rotten, have a look inside the tank too check the lifter pump strainer and for any debris inside:
View topic: Fuel Tank cleaning *HowTo* clear that blockage - The Mk1 Golf Owners Club

Hi, checking in progress. Did tou mean the screw that looks like this ?

Yes that is the 7mm Throttle body Idle by-pass screw.

Okay well even touching it makes it move. I will screw it off and put new o-ring ? Or do i need to take the rubber pipe off ?

No, you can remove the screw, Just count the number of turns to remove and then return it to that value.

Again wrap the Threads and threads only with Teflon tape, the yellow gas type works a wee bit better.

now its done, o-ring was hard like a rock. also cleaned throttle body at the same, lets see what happens, distributor cap and rotor were also awful..

Well idle is now perfect but hesitating still appears, by the way how should throttle switch functioning check do ? I mean if idling and i touch the switch nothing happens.

Strange but now it does like it that when the engine is cold or started again it runs perfect for a while.

flaky grounds, bad 02 sensor if equipped, bad cap or rotor….. Vacuum leaks.

The Idle switch?  the one at the top is the WOT, and the twos switches on the bottom are a go/nogo.

when it hesitates what are the symptoms?
The Tach drops revs then comes back, to the gauges flicker when this happens.
Is there a loud whine from the right rear wheel arch?

get the idle and co reset, you've fixed an air leak.

the switch on top of the throttle body6 is for the cold throttle enrichment system, it sends power to the metal valve on the airbox.

if the valve also detects load form the vacuum pipe to the inlet it sends power to the 5th injector, which will only fire if the engine is cold

rubjonny said

get the idle and co reset, you've fixed an air leak.

the switch on top of the throttle body6 is for the cold throttle enrichment system, it sends power to the metal valve on the airbox.

if the valve also detects load form the vacuum pipe to the inlet it sends power to the 5th injector, which will only fire if the engine is cold

PSST Digifants don't have a 5th injector.

How can i do the reset ? Well rpm doesnt drop but acceleration feels like sticky. Like getting off from bubble gum. 

oops ignore all of that, I forgot this was a digifant thread. all of that is for later DX and EV kjet engines

for the reset follow the procedure in my digifant guide, link on page 1. I wouldn't bother messing with the CO though unless you have access to pro equipment, just do the base idle check. the DIY CO meters don't work very well I find. Print the guide out and show it to your local garage

Petrif91 said

How can i do the reset ? Well rpm doesnt drop but acceleration feels like sticky. Like getting off from bubble gum. 

That could be but not limited to the Throttlebody Stop incorrectly positioned, the Throttle body butterfly can stick on the TB if the stop isn't correctly positioned…
The Screw on the top of the TB isn't for Idle speed adjustment.  It is to position the butterfly so that it can't jam closed.  It is adjusted for the butterfly to be about 2 (RPH)from complete closure factory set and usually never needs adjustment unless you dinked with it.

The throttle position switch (on the bottom of the throttle body) is to tell the ECU that the butterfly is out of the rest position and that you should be increasing the rev of the engine.

From the looks of it you can remove the Accel Cable and manually feel if it is binding.  If it is then Spray WD-40 on the return spring, and work it if it goes away then it was the mechanism that was binding if it doesn't then you need to remove the Air Tube to look at the butterfly if there isn't a small GAP between the butterfly and the TB throat, then that could be your issue.

As I stated the micro switch at the top is for WOT (Wide Open Throttle) (it is actually called the Full Throttle switch) it can be tested as a go/no-go open when off closed when depressed with a multimeter.

When the car is running there should be 5V on one side and open on the other closing the switch sends the 5V back to the ECU.

It sends a signal to the controller (ECU) that full throttle enrichment is to be used…..

I have never had to make a Idle Adjustment on the MAF, and from what I have heard it doesn't make a whole lot of difference anyways.

Timing, Timing Timing, is the best thing you can do.

Oh, another gimme,,,,, Read more about it in the Bentley Section 5-page 55

Don't have a Bentley, I would get one, it was the 3rd Tablet handed down to Moses.

rubjonny said

oops ignore all of that, I forgot this was a digifant thread. all of that is for later DX and EV kjet engines

for the reset follow the procedure in my digifant guide, link on page 1. I wouldn't bother messing with the CO though unless you have access to pro equipment, just do the base idle check. the DIY CO meters don't work very well I find. Print the guide out and show it to your local garage

Well we all can't be right all the time but you do tend to be spot on.  

in my defence I didnt get much sleep last night and only had 2 coffees in me

Thinking about it the co% screw may not make so much difference on the US models which have the lambda sensor to help the ecu compensate, but for the UK PB engine without one you need this set properly else it can result in drivability issues especially if its way out.  

I found this out the hard way, used my brand new gunsen CO meter to set mine to '1.5%' but when it was checked on pro equipment it was found to be more like 0.2%. This led to really bad juddering when cruising at steady speeds from time to time asnd it stank of fuel as it was chucking out loads of unburnt hydro carbons out the back.

I'm not sure if the PF engine sold/imported to the UK market would have a lambda or no, but its an easy check just get underneath and look in the exhaust downpipe/cat

Thank you again, lets see what happens when testing. BTW where can i get that bentley ?  

Petrif91 said

Thank you again, lets see what happens when testing. BTW where can i get that bentley ?  

Amazon or a good used bookseller should have them.