GLI loses power, Rpm Drops, feels like it runs out of gas. PLEASE HELP!!

[gli16]

Hi! PLEASE HELP!!!!

I have a '92 GLI 16V and what has been an issue for about 1 year:

Car idles rough and at times the RPM drops and loses power. After a couple of minutes it barely starts
I have replaced:

Fuel Pressure Regulator
Fuel Accumulator
Fuel Filter

Fuel Pump works and Transfer fuel pump works.
all Vaccum Lines seem good....

NEED HELP....IM AT THE END OF THE LINE

[antichristonwheels]

cat melted down?

[gli16]

uh....you mean has my Catalyic Converter melted?
not sure.....

I'll take a gander at her...

[91JET16V]

Timing? Air fuel mixture?

[Bruce67]

The problem just started in my 89 GLI also. I had a similar problem in my old 16v Scirocco....it seems like the timing just all of a sudden gets heavily retarded and advances very slowly, causing the car to have a hard time accelerating. A knock sensor can cause this, and possibly the full throttle switch. I have replaced both on my car recently, but its still doing it. I replaced the ks on the Scirocco and it cured it.

[armymech666]

The problem just started in my 89 GLI also. I had a similar problem in my old 16v Scirocco....it seems like the timing just all of a sudden gets heavily retarded and advances very slowly, causing the car to have a hard time accelerating. A knock sensor can cause this, and possibly the full throttle switch. I have replaced both on my car recently, but its still doing it. I replaced the ks on the Scirocco and it cured it.

That is exactly what mine does. And it throws a CEL right when it happens and then stays on. It seems to do it the first time i put load on the engine. I have replaced both of my knock sensors but I haven't checked the wiring to them yet.

[gli16]

Would you know where the knock sensor is??
on a 92 16V GLI?

i cannot find it.

[armymech666]

There are 2 on the front of the engine They are round with a bolt in the middle. They have a thick wire that should go to a green or blue connector.

[ekua516]

Did you try looking for codes?

[Bruce67]

One of the other things to check is the condition of the vacuum line that runs to the knock sensor control unit, which is located under the rain tray on your left. There is a small hose that connects the plastic line to the kscu, and some of the times this hose is suspect. Its good to also check all of the other vacuum hoses as well. Everything on my car is in good shape, so I am guessing my problem may be in the kscu. I am going to work on it this week and run some more tests and I will update then. If you replace the knock sensor, it is extremely important to properly torque the bolt to the correct inch pounds, or you will crush the internals of the sensor, making it useless.

[my02VR6]

One of the other things to check is the condition of the vacuum line that runs to the knock sensor control unit, which is located under the rain tray on your left. There is a small hose that connects the plastic line to the kscu, and some of the times this hose is suspect. Its good to also check all of the other vacuum hoses as well. Everything on my car is in good shape, so I am guessing my problem may be in the kscu. I am going to work on it this week and run some more tests and I will update then. If you replace the knock sensor, it is extremely important to properly torque the bolt to the correct inch pounds, or you will crush the internals of the sensor, making it useless.

The torque is also not specific (a range). If you set it too high, it will sense too much knock; also if it's too low, less knock.