Find me an answer

[coolhandluke]

Let me start by saying, if you can help me out, I am in your debt, because I might actually get to sleep instead of searching for answers through the night. This is my first post on this forum so I am hoping someone has an answer in a 2008 a4, 2.0, quattro, manual tranny. A few weeks ago, started having problems with acceleration, basically felt like fuel cut off, release accelerator or downshift, everything back to normal. I know I know, cam follower. However, never had check engine light. Then was put into the hospital and had emergency surgery on my hand with a septic infection. Yes fun stuff. Long story short, I started working on the car a few days ago. Car was running, still no check engine light. I replaced the fuel filter, coil packs, and spark plugs. That was my starting point. Sat down, turned the key, everything starts right up. Turned it off to put the engine cover back on, sit back down to pull out of the garage, and nothing. Car will crank but will not start. And yes, we checked the battery charge. So, I check the fuel filter, fuel is moving freely through it. Check the line coming into the hpfp, and i have fuel delivered to at least that point. Pulled the spark plugs, and I dont see or smell evidence of fuel moving through any of them. I even went as far as to put the original spark plugs and coil packs back on, but to no avail. I have removed the battery terminals, hoping that maybe i just needed to clear something, but nothing. It was a stretch i know. Any advice is welcome, I have been trolling forums for days now, and I cannot find anything that seems to be an answer. Also keep in mind my nearest Audi dealer is Nashville, and towing it there is not a reasonable answer.

[johncaravello]

Fuel pump getting juice? Does it have a reset?

[coolhandluke]

I pulled the flexible low pressure fuel line from the pump and it was definitely getting fuel. Now as to if it is passing through the pump i cant tell.
I'm not sure what you mean by reset. If you mean a reset on the pump, I don't believe so

[johncaravello]

Some electrical fuel pumps have shut offs in case of accidents. I dont have my audi yet so i dont know. listen for pump to turn on(prime) before starter cranks. Also check fuse for fuel pump. I doubt it but its better than doing nothing and takes a minute to check.

[coolhandluke]

Yes, have done both actually. Pump primes and the fuse is good.

Like I said, I am completely out of ideas. Next step is to pull the high pressure pump see if something is going on there.

[johncaravello]

Sorry I couldn't help. I does sound like some kind of fuel delivery problem though. Good luck dude.

[coolhandluke]

No worries, trust me I appreciate the suggestions.

[rhodes991]

Responded to your other post. If the pump is priming than it should be fine (unless it isn't puching enough fuel pressure). Since you replaced the coil packs I think you are not getting juice to the packs. Not sure why, but double check you reconnected everything correctly and check all your fuses. There might be one that popped.

Might try and call an Audi service department and explain what you did. They may have some suggestions (beyond bringing the car into them).

[audi777tom]

I would suggest pulling each one of the plugs/packs again. You can try two tricks to see if you're getting spark first, and then fuel.

I haven't tried this on an audi yet, so this may be hard with the coil packs, but try to pull each plug individually and let it rest against the manifold or block (grounding the plug) and crank the car in a dark area (or with a friend). You should see a spark as the engine cranks through its rotation.

Second, you can try pouring a little gasoline into each cylinder with the plugs removed. Cap them back up and the car should run for 30 seconds or so until all the fuel in the cylinder is used up. This may also have an effect of "pulling" the fuel from the pump and may cause a blockage to clear.

Again, these are mainly tricks for older cars, but the principles should still apply.

As for the third part for combustion - air. I guess you can try to pop off the air filter and crank it.

The other thing that I've seen happen is the battery will be fine, but the ground cable will be completely corroded. So you get good voltage at the battery, but there is no power to the engine. This is a little bit of a stretch for a 2008 (usually seen in 30+ year old cars) but maybe a bolt is loose or something.

Good luck.

[audi777tom]

Thought of something else. Again, I've done this on another car, not an Audi. Find the mass air flow sensor (not sure where is is on these cars). Pull the connector to it and try starting the car. This should have the effect of putting the fuel/air ratio into open loop (preset value). Do not run the car long if it does start up, as you can easily be running lean in this configuration. Just another diagnostic idea.