What things to check when car hesitates during WOT?

[CaptainAwesome]

I have a 90 8V that idles smoothly most of the time, Lately it's developed hesitation at WOT only - Other than that it runs fine. Only problem is I recently found a coolant leak from the hot side of the radiator. New radiator ordered already.

Timing hasn't changed, Could use a tune up though. But then why would it only miss on WOT?

It's possible the o2 censor is bad. But wouldn't I get worse gas milage and be running rich too?

Is it possible a vacuum leak could cause this? If so - which line should I check?

[GG.]

1.6 carbo? Vr6?

[PDXGTI8V 2.0]

check your Bentley manual for the testing procedure for the throttle switches....also, you're basically saying the car needs a tune up and to have its vacuum hoses replaced....

come back and talk to us when you fix those things and let us know if you still have the problem...

[CaptainAwesome]

1.6 carbo? Vr6?

8V 1.8 Digi II Engine code RV

check your Bentley manual for the testing procedure for the throttle switches....also, you're basically saying the car needs a tune up and to have its vacuum hoses replaced....

come back and talk to us when you fix those things and let us know if you still have the problem...

Thanks, would not have thought to check the switches themselves.

[J.Knipl]

8V 1.8 Digi II Engine code RV



Thanks, would not have thought to check the switches themselves.

since it's a digifant I would not hesitate to put in a new coolant temp sensor. $10 not much of a gamble .

[91MK2Jetta]

obstruct catalytic converter could be a culprit

[CaptainAwesome]

since it's a digifant I would not hesitate to put in a new coolant temp sensor. $10 not much of a gamble .

So I see people mention this as a possible reason all the time - but I just don't understand why.

Coolant temp should not effect anything. Car's not overheating. I will change it to see if that helps anything.

Also an update to this - it's gotten worse, and I checked the WOT/Idle switches, which are working perfectly.

[nbvwfan]

So I see people mention this as a possible reason all the time - but I just don't understand why.

Coolant temp should not effect anything. Car's not overheating. I will change it to see if that helps anything.

Also an update to this - it's gotten worse, and I checked the WOT/Idle switches, which are working perfectly.

Becasue the CTS affects the fuel map, especially on Digi.
It is a thermosistor and should start at about 3K Ohm at ~60F and drop to ~400Ohms at running temp.
If your CTS does not do this resistance sweep, you A/F map is off on another planet, usually rich and at WOT, causing an overfuel until the engine can clear it's throat.

[CaptainAwesome]

Becasue the CTS affects the fuel map, especially on Digi.
It is a thermosistor and should start at about 3K Ohm at ~60F and drop to ~400Ohms at running temp.
If your CTS does not do this resistance sweep, you A/F map is off on another planet, usually rich and at WOT, causing an overfuel until the engine can clear it's throat.

Ah- Now I understand why it makes such a difference...