2.8 woes

[30 Valve]

whats up everybody, im new here and am looking for some help to get my 1998 2.8 30 valve running up to par before I go supercharger.

I always had my eye on these older a4's since they first came out, and I finally got one a few weeks ago and its going to be my little project.

it idles rough on cold start up and barely stays running. when I rev the engine, it sometimes makes a backfiring popping sound coming out of the intake. when I try to drive it, it bucks horribly.

I went to fuss around with it today for a few minutes and I think the fuel pump took a dump. fuel pump fuse is okay, I swapped fuel pump relay with a known working one and it still did not start. I cracked open the fuel lines(one at a time) and cranked the car, no fuel came out. also, I dont hear the fuel pump humming when the ignition is turned on. i installed new fuel filter and spark plugs when i got the car.

these are the codes I scanned before the fuel pump took a dump today.
P0118-coolant temp sensor
P0102-maf circ low input
P1545-T.P. control malfunction
P1559-idle spd control malfunction
P1602-power supply (B+) terminal
30 low voltage
P0322-ign/dist engine spd no signal

before the fuel pump died, I unplugged the maf and coolant temp sensor one at a time to see if the car reacted any differently, it did not.

any help or input would be highly appreciated

[Wrath And Tears]

If you ever see a coolant temp code replace the sensor. They cost like $20. If its busted and saying the coolant temp is 90C when its 20C the car will run rough and possible not start. If the car thinks its hot it won't use enough fuel. Same for the other way around, if its reporting cold when hot then it will over fuel the car. If the sensor is bad and reporting high then unplugging it won't do anything because it will default to a warm coolant temp reading in the ecu.

Have you messed with your battery recently? Has it been tested? Low voltage code gets set when you unplug the battery or its weak. Clear codes, replace the CTS, and see if it starts.

If you are 100% its the fuel pump use a pressure tester to see what the fuel rail pressure is while cranking.

[30 Valve]

I had the battery disconnected. it may be weak. the coolant gauge on the cluster shows normal when the car warms up, and how am I supposed to know if the coolant temp sensor is reporting high or low?

what good is a fuel pressure test going to do if the fuel pump doesn't turn on? I already cracked the lines and cranked the car and no fuel comes out.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

[Wrath And Tears]

Sorry I stopped reading before you mentioned cracking the lines.

Check for power and ground at the fuel pump, if they are present then replace the pump. You pretty much did every part of diagnosing a fuel pump except for that.

[30 Valve]

Sorry I stopped reading before you mentioned cracking the lines.

Check for power and ground at the fuel pump, if they are present then replace the pump. You pretty much did every part of diagnosing a fuel pump except for that.

No problem. I will get a coolant temp sensor tomorrow and check the power & ground at the pump tomorrow.

do you think I have a bad maf and bad throttle body too? what would be the best ways to check these out so I dont buy parts that dont need replacing?