dalspaugh

I've noticed through the end of the winter that my b4 has been starting worse and worse. Finally on Tuesday morning it stalled while trying to start and it did it again this morning after it not being driven yesterday. The car turns over and fires about how it always has, but the following few seconds are extremely rough. Then, like nothing is wrong it usually jumps right up, revs up for a second and idles fine.

A couple other recent symptoms:
Tuesday, getting onto the highway, heavy throttle through the lower RPMS 2-3K, I noticed some bucking.

Last weekend, running 70-75mph at full temp, I got a CEL, the car was running fine though. On the ride home that weekend, no light.

I haven't had a chance to check the code on that yet, hopefully this weekend.

I did plugs & Wires at 80K (from blauparts.com), car now has 98K. My initial thoughts were an ignition problem, maybe the coils? I've ordered a fuel filter since I have no idea when that was done anyway. Any insight would be appreciated!

Luxus Panzer

Get us the CEL code man, it was there for a reason


Stalling @ idle... remove clean and reinstall your ISV. 25 min job. 10 if you have done it before.

dalspaugh

Thanks for the response, the only code in the computer right now is

2341 - Oxygen Sensor Control 1

I found a list from another forum for possible problems:
fuel pressure high/low
Spark plug or wire issue
intake air leak
exhaust leak
faulty 02 sensor
Aux fuse 28 faulty (what is this?)
EVAP Canister purge regulator valve n80 sticks

While I had a moment yesterday, I tried to get to the ICV based on what I found on 12v.org. I tested the electrical resistance (8.2 ohms) and it was fine. When I tried to take it out to clean it, I couldn't because while trying to get it off the studs, it was interfering with some sensor on the coolant pipe that runs between the heads. Am I missing something here?

I checked all the vacuum lines loosely, and all the ignition wires for a solid connection, everything seemed ok...

Fuel filter is on the way, hopefully I will have time to replace it next weekend. Any thoughts or recommendations would be appreciated! Thanks!

dalspaugh

Also, I will be the first to admit that my exhaust has issues. I have another stock B4 90 exhuast system, I just need to find the time to install it, So I guess there is that too.

dalspaugh

Anyone for a tip on getting the IVC valve off? It really didn't seem like it would clear whatever sensor (coolant temp?) is on the coolant pipe that runs around to the back of the heads.

dalspaugh

bump for some guidance on getting the IVC valve off. Do I have to remove whatever sensor is on the coolant pipe that runs around the back of the heads?

Luxus Panzer

To get the ICV off, unhook the electrical connector on the sensor that is getting in your way (sensor on coolant pipe)

You may have the old version "big" isv and if so..it is a pain to get off.

Check the classifieds on QW... some dude there has a bunch of small ISVs for sale

dalspaugh

Yes! Thank you, it is as simple as pulling off that connector. I had some time and a beautiful evening yesterday to pull off the old ISV and swap in one I bought on Audifans that the seller confirmed was working when pulled.

The old one didn't look bad though when I pulled it off. Very clean looking cylinder/valve. I popped the other one on anyway.

Unfortunately, the car started just as rough this morning as ever so I don't think that was the problem.

I got some new codes though and pulled them last night while swapping the ISV. I got:

2212: Throttle Position Sensor
2331: Oxygen Control Sensor 2
2341: Oxygen Control Sensor 1

Could it be as simple as the TPS? Other thoughts? Thanks!

My next plan of action is to swap the fuel filter, it's never been done in the 30K I've had the car.

grillage

The TPS can cause some wacky stuff. I've replaced TPS's on my S6 and my old B4 90

Try this for troubleshooting...

dalspaugh

Does this change for my AFC V6? I'm guessing this sensor isn't too hard to get at, so I don't mind replacing it.

Seems to me that if the ECU is getting faulty readings then the 02 sensors will read different than expected (more or less 02) which could be the reason for the 3 faults... Reasonable logic?