Strange Engine Problem

Yoktomasured vaccum seems alrigt but i dont realy know how i do it? or where.

Nitro Anyway, you'd better tell something usefull Premo then to aks, who's topic is this.  

Hey, Yokto, I gave your problem a little more thought into it. When you said your motor rev up to 2k and back to 1k, Is that during idle or at full throttle? I think if it does that when your driving, it is possible the MAF is bad. Check your plugs to your maf to see if its loose because those tend to break at the clips. Or if you have a friend with the same car, try swapping in his maf to see if it changes anything. Sometimes checking it doesn't cut it. I also really recommend you to go back and do the vaccum test. Hook it up to any ports off your intake manifold as long as its not your fuel regulator hose. Watch the needle at idle! Let me know what the needle does and Ill tell you the possibility. Be specific with what the needle does because it can tell you alot of stuff. For example: burnt valves, broken valve spring, etc.
For your boost problem, I don't know if your refering to reading boost during idle or in motion. But, at idle at full throttle up to 5k or 6k, boost guage will not read anything just 0. It only give you a boost reading when the car is being driven.

As i said before, the engine works fine in idle no problems at all, its when i press the throttle my problems kicks in

*At no throttle engine works fine

*At a realy small pressure on the pedal the engine wors fine.

*At more then a small pressure at the trottle the engine goes up in rpm a bit, dies and start again when it reaches lower rpm,

*the higer the pressure of the trottle the lower rpm when it "dies"

*the engine never "die" compleatly and when i relese the trottle from the "start and die thing", it idles as nothing was wrong with it.

*no missfires

ive checked alot of connections and even tryed to unplugg the maf when the engine is running, it makes the problem worse.
ive tryed cover the hole under the air filter then, the engine stops running.

And premo: ive changed alot in the ignition system, but i dont think thats a problem my storboscope flashes when it goes in to (die mode) so i should have a spark.
Timeing and compression has been tested.

im gonna check the vacuum lines again tomorrow and try to explain how the needle act. also all the sensors.

Did you tried to take the other MAF for a test?

But anyway, when you unplug the MAF, the engine must keep on working fine on idle, but air / fuel mixture will be too reach...

I have another option, try unpluging your knock sensor to see if it does anything. If you dont know where it is at, it should be under the intake manifold on the block. I dont know if anybody asked you yet but have you checked your timing maybe its off. Sometimes a worned out timing chain streches and will throw off timing.

rookieI have another option, try unpluging your knock sensor to see if it does anything. If you dont know where it is at, it should be under the intake manifold on the block. I dont know if anybody asked you yet but have you checked your timing maybe its off. Sometimes a worned out timing chain streches and will throw off timing.

Your knocksensor or detonation sensor should have 2 wires from it, black which is grounded and white (+ from computer) It should be bolted to the block, most likely under the intake manifold. It should be flat and round and is the only sensor bolted to the block. sorry I dont have pictures! If you haven't already done so, check your air regulator and Idle speed adjusting screw.

Ok now i cant check much more, the thing does not start at all anymore, or when i spray som starter gas its about to start, then its completly dead untill i give it more starter gas. its much colder outside nowdays too, maby thats why.

I am adding to this thread. I have the same problem now, including delayed throttle response and a vicious idle.... intermittently.

unplugging the MAF is not a way of checking it

We had a similar problem on my sons car. Would idle fine but not rev past about 2k, then would rev from idle to 2k with steady throttle pressure.(Also ran very RICH) We replaced: plugs/wires, cap, rotor, ecu, tps, fuel inj cleaner, tested fuel pressure, been in two shops. Finally I actually took apart the mass air meter( don't know the correct way to test) One of the two VERY TINY wires that measure air flow was BROKEN, We are now waiting for our replacement,,,,,,,will re-post

Did you check the ECU codes? Did the MAF circuit show up on it?

So it was the maf, but ive been checking that one.
 now i wonder are at the temeraturmeter, anyone know where its at and how i mesure it?

Now i´m taking over this thread..  
I got Yokto´s s12!!!...

engine starts again but won´t do so easy...
Hard to get running at all..
found some issues that could be the problem om this..
1. I´m getting a weak spark..
2. Can´t see if the timing is right because the strobe is missing 15% of the time..
3. the engine cut´s out when the throttle is being pushed to fast..
4. Wont start warm or even when it was started earlier..

I have a MAF from a N14 GTI Sunny/Pulsar SR20de but this one only got 3 wires so i guess it wont work on the S12 but it looks the same and have the same dimensions... can i make an conversion to make it work?? anyone??..
I have tried everything that´s being offered in this thread but changing the vaccum hoses but its coming soon.. the injektors will be changed soon to when i have the money..
first i´m getting "new" coils and wires from a member...  

if i remember right this reving prob is a coil prob.... switch your connectors on the coils not the actual plug wires but the harness connectors..and see if that help as only one coil actually sparks to redline and the other only until like 4k i believe....

just curious, do you have good grounds?

get a piece of heavy gauge wire, like you would use to power an amp or something, and make a good ground strap going from your engine to the chassis, and clean up your neg battery cable at the battery, and where it meets the body.

IggyEGuanaunplugging the MAF is not a way of checking it

very tru as i have done this before car will idle but wont do much else lol

checking it is as easy as using a dvom to check the voltages, but years ago i learned people would rather keep asking questions on the internet, and spend money swapping parts, then try to learn/buy a new tool.

brewster240checking it is as easy as using a dvom to check the voltages, but years ago i learned people would rather keep asking questions on the internet, and spend money swapping parts, then try to learn/buy a new tool.

bartc_jif i remember right this reving prob is a coil prob.... switch your connectors on the coils not the actual plug wires but the harness connectors..and see if that help as only one coil actually sparks to redline and the other only until like 4k i believe....

bartc_jyou dont even need that a 12volt battary and a voltmeter is all you need to check to see if the afm is working

I´m going to check MAF and will try to clean it tomorrow...
Could the lamda do something like this?..
I have cleaned the coil connectors some weeks ago with no luck...
I will go over the grounding wires again too..
I´m going to try another lamda got some extras around..

Is the fuel pressure suppose to drop instantly when engine is being shut off??
because now it does..   Did´t do that last week... I did put a bottle of redline fuel system cleaner in the tank.. maybe thats why it drops?

This car have had this problem for about two years now according to Yokto but it is getting worse because now it don´t start easy like it did when Yokto was trying to get it running properly.. Since I got it I have changed the spark plugs to standard and cleaned out all sensors i found.. some were drenched in oil from the turbo and had allot of residue on them.. even the cold start is now clean..
what happens when the CAS craps out?? How does the engine behave?

Cheeked the MAF with my ohm meter but it seems to be ok...
Maybe I did it wrong... But I get readings from all connections..
How do I get the right readings from it??
which MAF work on the CA18et??

Now I get the engine starting pretty good.. well it starts anyway..
but runs rely bad...
Will try to put in a video clip of rev and boost meter...

Sounds like your fuel pump is crapping out on you. Hook up a fuel pressure guage and rev it up see if it maintains fuel pressure when you rev it. Also when was the las time you replaced your fuel filter?

s12turboinvegasSounds like your fuel pump is crapping out on you. Hook up a fuel pressure guage and rev it up see if it maintains fuel pressure when you rev it. Also when was the las time you replaced your fuel filter?

It Was the Knock sensor.

Now it runs perfect well in another chassis but anyways it runs.