Stalling after full boost with bigger turbo.

[jogi730]

Not wanting to hijack thread, just saying having same issues.
No leaks. I will report findings if/when I ever get them.

[Jimmaey]

what is dizzy timing ? ps my diverter valve hisses on low boost but no sound under full load. perhaps the spring is too tight because it was very hard when i tried to push the piston back in. it did go in.. i had a diverter valve failure on my 1.8 t but my ecu tried to correct that were as in here theres no correction. i did a boost leak test as described on sjm autotechnic. i plugged all leaks which very minot.im going to check for a correct connector for my laptop to check on vcds. had a bluetooth connector but vcds didnt.recognize it. it could be ignition coil failure because i had one sparkplugwire that would go haywire .when i put the sparkplug ontop of the sparkplug the car ran smooth. perhaps its all connected and the ignition coil is shot.

[Rikki Kitto]

I seem to be having a similar problem with mine at the moment. When it starts to boost, the engine just cuts out. They are having a mare trying to solve it at the garage

Does it feel like it's gonna chuck you through the windscreen

[tomwood_uk]

Does it feel like it's gonna chuck you through the windscreen

Overboost cut is brutal isn't it

[newsh]

Stalling after full boost with bigger turbo.

Dizzy timing

If you have spark plug leads then the engine is a 3B, so you have a distributor.


Is your distributor correctly timed?
Flywheel zero mark and marks on distributor rotor and body?

Also, post a pic of your rotor arm

[jogi730]

Does it feel like it's gonna chuck you through the windscreen

I think sums it up.
The most frightening was the first time it happened. Outside lane on motorway , WOT with cars behind then engine cuts out

[RichLV]

I think sums it up.
The most frightening was the first time it happened. Outside lane on motorway , WOT with cars behind then engine cuts out

Mine was doing the same. But it wasn't overboosting. It was our precious Bosch F5DP0R's misfiring over multiple cylinders at once.

[Quattronaut]

What means "engine cuts out" and "stalling"- there are two ways of that I know.

One is "emergency program"- when boost is reduced from 1,7 to 0,4bar, that feels like soft braking. That could be boost leak, sensors like MAF, IAT, MFTS, or some other things.
The other thing is bad ignition- that one is much harder, feels like a hard, fast step on the brake. Mostly reasoned by bad igition timing or wrong finger e.g.

Don´t spend time and money on testing the fuel pump condition. Just relay it, and you´re safe, the "how-to" could be found somewhere in here. With a good K27 on full throttle you should way need that and it is not much money to spend.

Why do all guys in here change the FPR to another one when their car is running bad? Software is written for one FPR. When it ran good at the time, it was written, and sometime later it runs bad, there should be another reason than a wrong FPR. When it was tuned with a 4bar FPR, use a 4bar one. Try to find out, what exactly the software is written for, when you don´t know it.

[Jimmaey]

my spark plugs are new. okay so i need to check the ignition timing. first im going to get a new distributor cap and rotor . how do i set ignition timing on these models ? do i need the good old strobe light out or is it just adjusting everything to certain marks? thanks for all the comments guys. they have helpef a lot

[Jimmaey]

quattronaut. my acceleration is this : minor horsepower untill i hit the 5000 rpm , then i get some stuttering followed by a kick in the back going full throttle. then when i use my clutch or try to come to a stop the engine just shuts off. it keeps shutting of even when i didnt go into full boost untill the engine cools down again. then it stays running on stationary like nothing happened.

[UrS4boy]

N71 Idle Speed Stabilization Valve (ISV or ISS Valve) Info

.. then when i use my clutch or try to come to a stop the engine just shuts off. it keeps shutting of even when i didnt go into full boost untill the engine cools down again. then it stays running on stationary like nothing happened.

Have a look at this:

N71 Idle Speed Stabilization Valve (ISV or ISS Valve) Info:

http://forums.quattroworld.com/s4s6/msgs/21853.phtml

[Quattronaut]

Ignition timing is set on standing car, no strobe needed. Very important: Very often the wrong rotor is bought and installed. There is a broad one and a narrow one, take the narrow one- I think it is selected to the NA 5-bangers, not to the turbo ones, but it is the one that works best.

For setting the timing you have to set the motor on tdc cyl1, and then turn the distributor to the right position. Try to do that very exctly; when I did it last time, I fixed the car with the handbrake against the gear under tension to prevent gear play. At the side of the motor there is a hole in the housing, where you can see the flywheel. Turn it, until you see the tdc/1 one mark (just a line), and then "finetune" it, that this line ist just below the upper edge of the hole. The turn the distributor until the two marks under the rotor are aligne, like you see in this threads picture http://www.audifieber.de/index.php/T...eiler-beim-7A/. That´s short explained- I think there are better explanations available

[Quattronaut]

quattronaut. my acceleration is this : minor horsepower untill i hit the 5000 rpm

Is that minor horsepower under full throttle, in the way of too little hp for the given throttle? Or is it minor hp in the way of only little throttle?

then i get some stuttering followed by a kick in the back going full throttle. then when i use my clutch or try to come to a stop the engine just shuts off.

When you hit the floor, it starts stuttering, then boosts-and then it pulls until you you lift your foot, and then it shuts completely down and has to be started again? Or does it loose power while pulling?

it keeps shutting of even when i didnt go into full boost untill the engine cools down again. then it stays running on stationary like nothing happened.

That´s only whith warm motor? Hot motor, after hunting it a few miles, or just normal running warm? And after it happened one time, it happens more often, still when you do not go full throttle, but maybe half?

Sorry for that askings- but it is not that easy getting it right complete sure while translating it an therefore being not sure

[RichLV]

quattronaut. my acceleration is this : minor horsepower untill i hit the 5000 rpm , then i get some stuttering followed by a kick in the back going full throttle. then when i use my clutch or try to come to a stop the engine just shuts off. it keeps shutting of even when i didnt go into full boost untill the engine cools down again. then it stays running on stationary like nothing happened.

Does it stall during gear shifts? Could indicate a bad bypass valve. Mine once popped out of the MAF hose during a drag race, the car stalled as soon as I closed the throttle plate (lifted the gas).

[Jimmaey]

nope no stalling during gear shifts. quattronaut its way too little horsepower under full throttle. it stutters when i hit the 5000 rpm just before the turbo comes on full boost. it doesnt lose power just the stall. its only after my turbo has spun its maximum rpm . else it just stays running. . i want to thank everyone for all the replies. i have had some alazing suppory here. tomorrow im moving my audi 100 quattro from 86 to my house. im going to try the rotor cap and distributor from that car. is there somewhere a good tutorial to reset the ignition timing again ? ill post pics of the old distributor next week. thanks guys !