Car wont start with codes P0688 and P0012

[04A4SC]

Hello I'm having a problem with my 04 A4 1.8T quattro 6 speed and hopefully someone can help me out I started my car the other day it was on idle in driveway for about 3mins car was all ready warmed up I backed out and drove about 4 houses down and she just stalled while I was in 2nd gear and she would not start up again after that she just tries to start but won't turn over I have 2 codes P0688 ecm/pcm power relay sense circuit and P0012 intake camshaft position timing - over-retarted (bank1). So far I've replaced the cam shaft position sensor for the P0012 code and did not help any and for the second code P0688 from what I've read could be the relay #219 located under the ECU in the ECU box went bad and fuse #29 20amp located inside on the side of the dash would be blown. Well fuse #29 was not blown and I switched relay #219 with a new 1 and the car still won't turn over. For awhile I've been hearing my cam chain rattling arnd could it be that my cam chain tensioner broke and that's what caused my car to stall and not restart and give me the 2 codes I'm getting. Ive also changed my spark plugs and checked to see if i had spark wich i do and i can smell gas when i took the plugs out so im getting gas aswell.And also at some point the block was changed many years ago from the AMB to a AWP so now do I get a cam chain tensioner/adjuster for the AMB or do I have to get one for the AWP I plan to order it tomorrow so any help on any of my many issues would be greatly appreciated PLEASE AND THANK YOU

[Pswish]

I'll help you get started and see if more attention comes your way. You may want to try the general forum too since only people looking to help come here:

Have you tried unplugging the MAF and see if it starts? Do you have a test light to test the CPS? Also, what is your voltage at the relay plate under the driver's side knee plate (at rest and then while cranking). It should be equal to the battery voltage and not less than 10v when cranking. If your Cam tensioner failed it may have thrown it out of cycle alignment which Could screw up when to hold pressure in the cylinders and cause it not to start. I don't know what tensioner to get but I would think the AWP since the tensioner is in the head.

[04A4SC]

Thank you for answering me I have not unplugged the MAF to see if it starts I will definitely try tomorrow morning and how do I go about checking the voltage at the relay plate I kno how to take the panel off and access the relays and other big fuses under there I just don't kno where exactly I'm to check and yes I do have an electric tester to measure voltage. My friend has the same car but an 02 he was gona let me pull parts off his just to check if it makes my car work but I rather find the problem if possible before I have to do that any and all help u or anyone can give me on how and where to test the relay plate I would realy appreciate it thank you

[04A4SC]

Oh and I also should add my traction control and ABS light have been on for about a month cause I need to replace the brake pressure sensor on the side of the ABS unit I have the new sensor just hadn't installed it yet cause I don't have the proper scanner to put the ABS unit into bleed mode now would that have anything to do with the problem I'm having now with the no start issue

[Pswish]

I had intermittent ABS problems when my voltage on the relay plate was too low. If you pull off the knee panel on the drivers side, and look up, left of the brake pedal, you will see a bunch of large red wires all connecting to a terminal strip. That is the relay plate voltage connection. Test from any wire to chassis ground. If you have more than .1v drop compared to the battery, you have a resistance problem and need to clean the connections.

[04A4SC]

It was the timing belt several teeth on the belt canes off so me and a friend pulled the head off checked and just replaced the head with a new used head and she's running great with a new timing belt kit and a new can chain tensioner kit and she runs like when I first bought the car at 70,000 I got extremly luck with a parts car that literaly fell in my lap and luckily just had to pull the motor from the parts car and not pull mine and I'm surprise at how well it runs