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

 

Did you clear the codes after re plugging in the maf and coolant temp sensor? Those codes may have stayed put so you might not need to worry about them.

Sounds like you need a new fuel pump. Check the lines going back into the pump (under the car) for leaks just to be sure. But since you don't hear any sounds and nothing comes out when you crank - seems like the pump is shot.

The other codes seem to point to a bad throttle body and possibly a bad crank position sensor. Throttle body can be cleaned fairly easily, just have to pull the vacuum hoses off + the snorkel pipe things that feeds air from the MAF into the TB. And the CPS is a real easy fix, just have to get under the car and reach up to find it.

I would put a new pump in, clear the codes then see what comes back.

Also check your PM's

 

I didnt clear the codes after plugging them back in.

I will most likely check the power & ground at the pump tomorrow. if thats good, I will get a new pump and coolant temperature sensor. I will try to clean the maf and throttle body and see what happens with tne new pump[if needed] and new coolant temperature sensor