jimrobertson

1996 2.8. Replaced fuel pump and temperature sensor. Now it starts,but hard starting.Replaced FPR and no change. Any ideas? I have a Bentley manual.

Brdman*

did you pull the codes? One of the Crank/Cam position sensors perhaps?

jimrobertson

I have codes P1101 and P1106.But They have been there (off and on)long before this.Can't find the air leak.Replacing the fuel pump got it to start,but it was not hard starting before.Runs great otherwise.This is a fuel pressure leak issue,I think.

dorsal900

The AudiWorld search function is currently down. What I can find elsewhere is that this is a MAF problem, which may not actually be the MAF but does indicate a mismatch of what the MAF is reading and some of the other sensors - which points to a likely air leak. I don't know why a fuel pump was done, but that's not the issue now.

Typical air leaks on the 12V engine:
1. Replace ALL vacuum hoses NOW! The fabric wrapped factory hoses will fool you into thinking that they are fine, but underneath the porous fabric the rubber is rotten and leaks.
2. Be very sure that the hose between the intake manifold and the throttle body plenum is properly attached and clamped. It's possible that you reinstalled them with a small pinch that is letting air enter.
3. Look at the PCV hoses on the back of the valve covers to ensure that they are attached properly and not cracked - the hard plastic material that they are made of is easy to crack.
4. Where the plenum attaches to the throttle body there is a rubber lip. If the guide pin bushings for the plenum are missing, this lip may not be sealing properly. A good trick to ensure a good seal is to put 1 inches of RJ-11 cable in the notch underneath the rubber lip - do a search when it is working.

jimrobertson

P1101=O2 sensor circuit.Bank 1 Sensor 1 voltage too low . Air leak.
P1106=O2 sensor circuit Bank 2 sensor 1 voltage too low. Air leak.
The fuel pump replacement got it to start. I will review the hose connections. All the fabric vacuum lines were done 18 months ago. I will check the specs on the maf too.I have a Bentley manual. Thanks for the 4 point guide. I will keep the forum posted. It is getting warmer in Ontario now so I can get back at it without freezing.
One thing to note, if I turn on the ignition four or five times until the fuel pump relay clicks it will start quickly. This means I am building the fuel pressure in the lines?