engine cranks but doesn't turn over 2008 A4 B7 2.0T

[holytexas123456]

Hi everyone, I Need help diagnosing a no start problem with my 2008 Audi A4 2.0TFSI b7

Changed intake camshaft due to lobe damage. All went well except now the engine will not start. It will crank and crank but not ever fully turn over. Ran compression test and 180 across the board. I expect the problem is fuel related but can't seem to narrow it down. Checked the the fuse and relay for the fuel pump. I first thought the problem was that I did not connect the ground on the back of the vacuum pump but fixing this did not help. The engine will occasionally sputter as if firing but then it will die. I ordered a vagcom usb reader on ebay in order to check for any codes related to the crankshaft camshaft or engine speed sensors. What should I check next? Thanks!

Here is a video of the engine cranking..

[aluthman]

How long have you cranked it for? I wouldn't expect it to fire after the short cranks in the video given that you had the fuel system open. After disconnecting everything it takes a good amount of time before it actually primes the lines and fires. Cycle the key on and off a few times to let the lpfp prime the lines, and then give it a good crank. It also looks like your O2 sensor wire is touching the manifold. That's unrelated, but probably something you should look into.

[Okedokey]

Open the door and close it a few times to prime the HPFP too.

[holytexas123456]

I cranked the car for a good 10-15 seconds and I have cranked it multiple times. I get a big spurt of gas out of the schrader valve when the engine is cranked so fuel is getting to the HPFP. Sometimes it will sputter once but usually it just keeps cranking. Also I hear the fuel pump when I open the door.

[aluthman]

Keep trying it. If it doesn't start after a few (4-5 attempts) 15-20 second cranks you might have an issue. Pulling codes will help once you get your cable, if there are any. The schraeder valve is on the low pressure side of the hpfp. Fuel still needs to fill the high pressure side and bleed out all the air from the lines. Bleeding fuel out of the schraeder valve is also prolonging the process of priming the system.

[vce1232000]

Id say it for a steady 40 seconds. If if doesnt start by then. Then you got issue's

[Okedokey]

If it is coming out of the release valve, then you're probably need to replace that right? Also check all your electrical connections again.

Can you scan with VCDS?

[bergy12]

Happend to me a couple weaks ago, everything was fine than one morning it just wouldn't start, it ended up being my low pressure fuel pump had just crapped out.

[Charles.waite]

Id say it for a steady 40 seconds. If if doesnt start by then. Then you got issue's

I wouldn't do that. That's going to kill the starter motor.

Honestly the car shouldn't crank for more than 5-10 seconds before catching. When I did this on my car is caught after about that. I bet you left something disconnected.

Try unplugging the MAF and see if it starts.

[holytexas123456]

I just received the vagcom adapter in the mail, I got it set up and the test goes through ok under the options menu in vcds lite. Unfortunately the auto scan function is not working and their is no option for a b7 a4 and only for a b6?

I tried unplugging the MAF and cranked for 15-20 seconds. The engine will sputter a couple of times on occasion but most of the time it just cranks. It sputters more on the first try or two (like there is residual fuel in the line). I double checked the other connectors visually and none are disconnected.

[Theiceman]

could your timing be off ? you need compression to get fire .. I know you have compression as you checked , but is the timing of the compression correct ? if we go back to basics and look at what you did you had the intake cam out . Amy be worth a revisit there. if you pop the plugs out do you smell gas or are they wet ? this would tell you that you are getting gas and its just not firing. ive never done a cam so cant advise further but if It was working before maybe someone who has done an intake cam can chime in on some common pitfalls.

[Charles.waite]

I just received the vagcom adapter in the mail, I got it set up and the test goes through ok under the options menu in vcds lite. Unfortunately the auto scan function is not working and their is no option for a b7 a4 and only for a b6?

I tried unplugging the MAF and cranked for 15-20 seconds. The engine will sputter a couple of times on occasion but most of the time it just cranks. It sputters more on the first try or two (like there is residual fuel in the line). I double checked the other connectors visually and none are disconnected.

You only need to scan the engine module for this.

Also is this a legit Ross-Tech cable or a knockoff?

Most knockoffs don't work with CANBUS which is what the b6 uses for the engine controller.

[Theiceman]

im guessing chineese knock off , I was using one on my 2000 a6C5 with vcds light. worked great for that but on the b7 it pops up communication fault. so time for the full on software, way more usefull on the b7 anyway

[Charles.waite]

im guessing chineese knock off , I was using one on my 2000 a6C5 with vcds light. worked great for that but on the b7 it pops up communication fault. so time for the full on software, way more usefull on the b7 anyway

Yup! Legit ones are worth every penny.

[holytexas123456]

Hi, got vagcom and got the following codes from the engine: P0422 P310B P0118 and P0100. The engine still cranks and occasionally sputters.

[holytexas123456]

Did a couple tests today, got this log:
Address 01: Engine (8E1 910 115 G)

18:33:42
28.0°KW Camshaft Adjustment (spec.)
28.0°KW Camshaft Adjustment (act.)
28.0°KW Bank 2 Camshaft Adjustment
50.00 bar Rail Pressure (specified)
51.91 bar Rail Pressure (actual)

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (8E1 910 115 G)

18:34:16
28.0°KW Camshaft Adjustment (spec.)
-38.5°KW Camshaft Adjustment (act.)
-38.5°KW Bank 2 Camshaft Adjustment
51.38 bar Rail Pressure (specified)
60.26 bar Rail Pressure (actual)

It looks like the camshaft adjustment is changing every time I crank but sometimes it is both 28 kw. What would this symptom be indicative of? Engine still cranks and occasionally sputters. and compression test checked out..any ideas? Thanks!

[aluthman]

Hi, got vagcom and got the following codes from the engine: P0422 P310B P0118 and P0100. The engine still cranks and occasionally sputters.

Unplug the maf, check lpfp fuse, make sure O2 sensor is plugged in and not damaged, and same thing with the coolant temp sensor at the back of the head.

[Okedokey]

Camshaft sensor? 06F-109-257-C (N205)

[aluthman]

Camshaft sensor? 06F-109-257-C (N205)

The N205 is not the cam sensor. The N205 is at the back of the head and controls oil pressure for variable timing on the exhaust cam. The cam position sensor is at the front of the head on the drivers side. None of his codes were cam related, but stranger things have happened.

[Okedokey]

May be, I don't know what the 'in spec' values should be.

One thing that caught my eye though is

51.38 bar Rail Pressure (specified)
60.26 bar Rail Pressure (actual)

[holytexas123456]

Not too worried about the fuel pressure, one of those readings was taken just after I tried cranking. What is strange to me is the camshaft adjustment (act) is always off by a random number or is sometimes at the (spec) value; the value changes every time I crank the engine. I am planning to take the timing cover off to investigate further today.

[Okedokey]

Howd you go?

[holytexas123456]

I opened the valve cover up. Everything looked good. VCDS auto-scan is clear. When I first go to crank the camshaft position is correct after cranking it changes to around -38.5°KW. When then I turn the key off and back on it will read the correct specified value. Any ideas?

[Okedokey]

Crank position sensor, N280?

[aluthman]

Cam position sensor is more likely.

[Okedokey]

Cam position sensor is more likely.

Thats what i meant to say :)

[dalmation53]

ughh any updates?

[AudiGuy818]

Similar problem. My solution was that my EFI and ECM relays were bad.

Hi everyone, I Need help diagnosing a no start problem with my 2008 Audi A4 2.0TFSI b7

Changed intake camshaft due to lobe damage. All went well except now the engine will not start. It will crank and crank but not ever fully turn over. Ran compression test and 180 across the board. I expect the problem is fuel related but can't seem to narrow it down. Checked the the fuse and relay for the fuel pump. I first thought the problem was that I did not connect the ground on the back of the vacuum pump but fixing this did not help. The engine will occasionally sputter as if firing but then it will die. I ordered a vagcom usb reader on ebay in order to check for any codes related to the crankshaft camshaft or engine speed sensors. What should I check next? Thanks!

Here is a video of the engine cranking..