Engine Swap- Nearly complete but Wont Crank At ALL, & Fuel Pump isn't priming. Ideas?

[TheDood.]

Okay, long story short- Bought a 2001 Allroad 2.7t as a project. Car wouldn't run, would try to run some but was terrible.. PO told me something vacuum issues, acted ignorant, low and behold it had jumped time and was mashing up one cylinder without mercy. I found a drop engine with turbos for cheaper than I was estimating rebuild.

Now I've got the engine in, everything I can see obviously to do done..

I put a battery in today and was planning on seeing how bad the fuel looked from sitting after changing the Fuel filter, but it Will Not Prime. (assuming it primes when you first turn the key all the way before cranking like my b6 1.8t) and it will not crank at all..

I'm getting a check engine and an EPC light. Im not very familiar with VAG com and I have a Mac.

At first turn- I did forget that I had pulled a lot of relays to see if they'd swap into one I was testing.. So duh- thats the cause. Well I plugged em all in and still nothing, so I let it set with the battery disconnected for 5 mins and tried again without change..

I thought this might have caused some funk, so I unplugged the ECU before I left..


Otherwise- Any other ideas what would cause it not to try to crank or fuel pump to prime? Of course I'll look at my wire harness to see if I missed anything that would involve it.

*** I didn't have a couple things hooked up that I did not consider essential to the fuel pump turning on- Coolant tank, the trans (Tiptronic) is bone dry, I originally tried without the front clip harness but have since plugged it in. Not sure if this stuff is relevant but I thought I should mention

Thanks-

[julex]

It will always crank so long there is power, ignition starter position is reached and relays are in working order, provided we are talking 6 speed. I am not sure about tiptronic but I imagine there must be some interlocking mechanism so people don't crank in gear (mechanical perhaps?)

The pump only primes for 1-2s when ECU thinks the fuel system was not primed so last several hours. It won't prime again if you just re-cycle the ignition.

I think you simply pulled too many relays , missed connecting grounds after engine swap or simply have some blown fuses to go with it.

And...first and foremost, don't admit to MAC!

[Vinchenzo51]

Check all connectors, crank position, ect. Check your grounds too. Like julex said, you probably just missed something.

[TheDood.]

Thanks guys! After leaving ECU disconnected and retrying I did get some fuel to come out, not much but maybe thats all it does with priming.. Still No Crank, so Its time to double check my work.. I've tried searching but any pointers on where to find some wiring diagrams or a list of grounding locations I may have missed?

[audifirst]

Get vagcom running if you have it... get cheap laptop under 100 with running windows doesn't have to be fast and get at least codes and see what is the issue ...
it will be hard to point to something that we do not know...

[julex]

Thanks guys! After leaving ECU disconnected and retrying I did get some fuel to come out, not much but maybe thats all it does with priming.. Still No Crank, so Its time to double check my work.. I've tried searching but any pointers on where to find some wiring diagrams or a list of grounding locations I may have missed?

Very little fuel comes out through priming so it is normal. While cranking though (with key in start position) it should engage the pump permanently. If it doesn't, then again, it is either you ignition switch (voltmeter!) or relay (voltmeter!). Not getting starter to crank is just another symptom of missing relay (or fubar switch).

Here are diagrams for S4: http://socals4.com/repair/ , give me you email and I can email you C5 allroad diagrams.

[TheDood.]

Working on getting VAGCOM set up- Julex- sent you a PM with my email in it..

[Vista461]

When I replaced the fuel pump on my 03 allroad 2.7 I noticed it really didn't pump fuel unless cranking. Pump wouldn't run with key on engine off, which was unlike every other efi car I've had.


Sent from my iPhone using Tapatalk

[TheDood.]

Bump De Bump-- - Have now successfully gotten VCDS Lite working on my macbook pro.

Codes- (some annotations from looking up unknown codes on rosstech site) :

VCDS-Lite Version: Release 1.2
Tuesday, 24 June 2014, 02:14:44.


Chassis Type: 4B - Audi A6 C5
Scan: 01,02,03,06,08,15,16,17,18,22,34,35,36,37,45,55,56 ,57,65,67,75,76,77

-------------------------------------------------------------------------------
Address 01: Engine Labels: 078-907-551-AZA.LBL
Controller: 4Z7 907 551 M
Component: 2.7l V6/5VT G 0001
Coding: 06752
Shop #: WSC 25641
VCID: 4DEDEA3794C9
WAUYP64B51N042923 AUZ7Z0Y1556596
10 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Shareware Version. To Decode all DTCs
P0301 - 35-10 - Please Register/Activate - Intermittent
16687 - Shareware Version. To Decode all DTCs
P0303 - 35-10 - Please Register/Activate - Intermittent
16686 - Cylinder 2: Misfire Detected
P0302 - 35-10 - - - Intermittent
16518 - Shareware Version. To Decode all DTCs
P0134 - 35-10 - Please Register/Activate - Intermittent
17862 - Shareware Version. To Decode all DTCs
P1454 - 35-10 - Please Register/Activate - Intermittent
17521 - Oxygen (Lambda) Sensor; B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent
18010 - Shareware Version. To Decode all DTCs
P1602 - 35-00 - Please Register/Activate
16486 - Shareware Version. To Decode all DTCs
P0102 - 35-10 - Please Register/Activate - Intermittent
16689 - Cylinder 5: Misfire Detected
P0305 - 35-10 - - - Intermittent
Readiness: 0110 1101

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01V-927-156.LBL
Controller: 4Z7 927 156 A
Component: AG5 01V 2.7l5VT USA 1414
Coding: 00002
Shop #: WSC 00000
VCID: 44FBCF134783
2 Faults Found:
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent
17090 - Shareware Version. To Decode all DTCs
P0706 - 35-10 - Please Register/Activate - Intermittent

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 8D0-907-389.LBL
Controller: 4Z7 907 389
Component: ABS/ESP allrad D47
Coding: 06397
Shop #: WSC 02313
VCID: 09651E272021
No fault code found.

VCDS-Lite Version: Release 1.2
Tuesday, 24 June 2014, 02:14:44.


Chassis Type: 4B - Audi A6 C5
Scan: 01,02,03,06,08,15,16,17,18,22,34,35,36,37,45,55,56 ,57,65,67,75,76,77

-------------------------------------------------------------------------------
Address 01: Engine Labels: 078-907-551-AZA.LBL
Controller: 4Z7 907 551 M
Component: 2.7l V6/5VT G 0001
Coding: 06752
Shop #: WSC 25641
VCID: 4DEDEA3794C9
WAUYP64B51N042923 AUZ7Z0Y1556596
10 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Shareware Version. To Decode all DTCs
P0301 - 35-10 - Please Register/Activate – Intermittent
16685/P0301/000769 - Cylinder 1 Misfire Detected

16687 - Shareware Version. To Decode all DTCs
P0303 - 35-10 - Please Register/Activate – Intermittent
16687/P0303/000771 - Cylinder 3 Misfire Detected

16686 - Cylinder 2: Misfire Detected
P0302 - 35-10 - - - Intermittent

16518 - Shareware Version. To Decode all DTCs
P0134 - 35-10 - Please Register/Activate - Intermittent

17862 - Shareware Version. To Decode all DTCs
P1454 - 35-10 - Please Register/Activate - Intermittent

17521 - Oxygen (Lambda) Sensor; B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent
18010 - Shareware Version. To Decode all DTCs
P1602 - 35-00 - Please Register/Activate
18010/P1602/005634 - Power Supply B+ Terminal 30: Voltage too Low

16486 - Shareware Version. To Decode all DTCs
P0102 - 35-10 - Please Register/Activate – Intermittent
16486/P0102/000258 - Mass Air Flow Sensor (MAF/G70): Signal too Low

16689 - Cylinder 5: Misfire Detected
P0305 - 35-10 - - - Intermittent
Readiness: 0110 1101

-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01V-927-156.LBL
Controller: 4Z7 927 156 A
Component: AG5 01V 2.7l5VT USA 1414
Coding: 00002
Shop #: WSC 00000
VCID: 44FBCF134783
2 Faults Found:
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent
17090 - Shareware Version. To Decode all DTCs
P0706 - 35-10 - Please Register/Activate - Intermittent

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 8D0-907-389.LBL
Controller: 4Z7 907 389
Component: ABS/ESP allrad D47
Coding: 06397
Shop #: WSC 02313
VCID: 09651E272021
No fault code found.

a


My #1 Suspect-
17090/P0706/001798 - Transmission Range Sensor (F125): Implausible Signal

Possible Symptoms
No Reverse Lights
Engine will not start
Incorrect Gear Selection
Gear Indicator Display (PRNDL) may be flashing

Possible Causes
Gear Selector Cable incorrectly adjusted
Transmission Range Sensor (F125) faulty
Wiring and/or Connector(s) from/to Transmission Range Sensor (F125) faulty

Possible Solutions
Adjust Gear Selector Cable
Check Measuring Value Blocks (MVB)
Check/Replace Transmission Range Sensor (F125)
Check/Repair/Replace Wiring and/or Connector(s) from/to Transmission Range Sensor (F125)


So I'm going to start with the wiring connections, I Know I connected them but I'l Check and clean..
I did not do anything special when connecting the trans cable, Was there something I was supposed to do? It feels to me like it goes through all the gears fine and its not flashing on the dash.. I thought it was an only one way deal.

Also the trans speed sensor- I do NOT remember reconnecting this, any details on its location? Is it wired to the trans harness or is it wired directly to the engine wire harness?

[julex]

speed sensor should be on engine harness (but don't sue me if it is on tranny part ), connector is on top of driver side flange, towards front of car on tip.

You can see it at 10pm above flange.

[rollerton]

Codes don't matter at all since "no start" and " no crank" are two completely different things. In your post you mention:
Otherwise- Any other ideas what would cause it not to try to crank or fuel pump to prime? Of course I'll look at my wire harness to see if I missed anything that would involve

So- does the engine not "crank" at all? If you turn the key and nothing happens then you have one or more of these problems: 1.Dead battery 2. Bad Ignition switch 3. Bad wiring/ground / relay from ignition to starter 4. Problem with starter interlock / shifter circuit. 5. Bad starter.
If it "cranks" but does not start then 1. Electronics/Wiring problem resulting in no spark 2. NO fuel 3. Sensor / timing problem.
Easy test. Pull the hose off that is in front of the MAF and spritz a little ether (starting fluid) in there- Not too much. Turn the key and see if it fires. If so go after fuel problem.
If no fire then go after electrical problem/ connectors/ Engine speed sensor. ^^Julex mentioned the speed sensor - the one you want to check is the one plugged into the bellhousing not the one right at the CV flange. Even though my car starts and runs without it conencted..I don't think it's supposed to, but it does.

[TheDood.]

Thanks again Julex- Speed sensor is indeed connected to the engine harness, and mine was indeed not connected.

I DO NOT have a sensor in the transmission, and I don't recall ever seeing one or taking one out. I did do a trans filter while I had it out, I don't think this is something that would've needed to be tampered with during and I don't remember needing to do anything else with it. I wonder if the PO had sold it to me with it out? It was cranking then though. I'm going to search the garage over for it and go ahead and order one. Would this be just cause for no CRANK? I've had other VW cars run/drive fine without this sensor plugged in, only effecting the speedo.

[TheDood.]

Codes don't matter at all since "no start" and " no crank" are two completely different things. In your post you mention:
Otherwise- Any other ideas what would cause it not to try to crank or fuel pump to prime? Of course I'll look at my wire harness to see if I missed anything that would involve

So- does the engine not "crank" at all? If you turn the key and nothing happens then you have one or more of these problems: 1.Dead battery 2. Bad Ignition switch 3. Bad wiring/ground / relay from ignition to starter 4. Problem with starter interlock / shifter circuit. 5. Bad starter.
If it "cranks" but does not start then 1. Electronics/Wiring problem resulting in no spark 2. NO fuel 3. Sensor / timing problem.
Easy test. Pull the hose off that is in front of the MAF and spritz a little ether (starting fluid) in there- Not too much. Turn the key and see if it fires. If so go after fuel problem.
If no fire then go after electrical problem/ connectors/ Engine speed sensor. ^^Julex mentioned the speed sensor - the one you want to check is the one plugged into the bellhousing not the one right at the CV flange. Even though my car starts and runs without it conencted..I don't think it's supposed to, but it does.

Touche' Rollerton. I am having a NO CRANK issue, it will not even attempt to turn over.
1- Battery good,
2- Ignition switch good before tear down,
3- Bad wiring/ground/ relay for starter circuit - Possibly,
4- Problem with Starter interlock / NSS - Possibly
5- Bad starter, it was cranking great before tear down.


So again, would the VSS being totally disconnected prevent if from cranking? or is that just an additional issue that would've come next?

[A62TURBO]

Are you sure the starter is seated correctly?

[TheDood.]

As sure as I was when I installed it a few weeks back.. I did turn it over a few time by hand to make sure it wasn't in a bind. I am not hearing any noise from the starter trying to turn or kick out or move at all..

[TheDood.]

Ordered a VSS & I'm going to try'n pull the one off my B6A4 and see if that will get it to crank.

[rollerton]

Touche' Rollerton. I am having a NO CRANK issue, it will not even attempt to turn over.
1- Battery good,
2- Ignition switch good before tear down,
3- Bad wiring/ground/ relay for starter circuit - Possibly,
4- Problem with Starter interlock / NSS - Possibly
5- Bad starter, it was cranking great before tear down.


So again, would the VSS being totally disconnected prevent if from cranking? or is that just an additional issue that would've come next?

^^No. Nothing in any engine electronics will prevent the starter from operating. And the VSS has nothing to do with the engine running. Nothing in any of the "electronic" or computerized systems can handle the load (amps) that a starter will draw. So no computerized parts have the ability to keep the starter from engaging.

What you want to check is the CPS (crank position sensor) - in the bellhousing. But again, the starter circuit is pretty straight and the CPS won't prevent the starter from engaging either.
You have B+ to ignition switch, and when cranking B+ to starter through the (shifter) interlock relay (that circuit is closed when the shifter is in N or P):- which is typically labled 53 and it on the top row left side of relay panel.
You can eliminate the shifter-interlock relay by jumping a wire (there are 4 wires to it) from the two hoziontal connections in the plug if you pull the relay out.
But- if it was me, I would jack the front of the car up and make sure the wire is pushed onto the solenoid correctly, and if so JUMP the B+ connection on the starter to the solenoid connection (with a screwdriver or something). This will operate the starter. TRANS IN NEUTRAL!!!!
If you have a good battery and it DOESN'T operate the starter then you have something binding in the bellhousing or a bad starter.
If it DOES operate the starter then check the voltage at the solenoid wire (push on) as somebody operates the ign switch. And trace from there. Go back to the relay and make sure the circuit is closing when the shifter is in P or N.

[TheDood.]

Jumped the starter as per your instructions in N. Starter spun over very freely but didn't turn engine over. So like you said, it's not properly seated?, or is the solenoid (or whatever would) supposed to kick the starter gear out into connection with the flywheel? I'm going to round someone up to turn key while I check wire for V as you suggested now.

[rollerton]

Take a small hammer and *tap tap tap* on the starter housing and solenoid. And try again.
I just went through some starter problems recently. Installed starter back in march- it went 3 months with intermittent no-start symptoms. Eventually narrowed it down to the solenoid. It would randomly do *nothing* but tapping on the solenoid would get it to work fine for a day or so. Then it would stick and fail again.
2ND replacement starter did nothing, it was just bad.
3rd one worked for 6-8 starts then the solenoid failed and the starter would just spin-spin-spin as long as the battery was connected.
I removed the 3rd one and rebuild it myself..that was 2 weeks ago, so far so good.
But yes, check B+ voltage as someone is working the key..but I suspect the starter if you jumped the conections (small push-on solenoid wire to BIG B+ battery cable) and the solenoid didn't engage.

[TheDood.]

Rollerton- I jumped from large battery wire directly to large starter wire. I just tried jumping from battery to solenoid and it did crank over the engine-

So, starter and battery are good? Wire to interrupted by either relay or starter interlock?

[TheDood.]

Ps that starter story sounds like a nightmare. Not a comfortable working space lol.

I just tested the solenoid wire with no results. Next would be to jump the relay? How do I test the starter interlock?

[TheDood.]

re read some of the replies from earlier- The VSS I'm speaking of is the same thing as the CPS, I think.

This is what Im missing:

http://www.ecstuning.com/Audi-All_Ro...trical/ES9480/

Not sure if this matters any more but to be clear-

[rollerton]

No^^ That's the VSS, it read the axle rotation. The CPS is in the "bellhousing" just in front of that same axle. It's held in by one small 5mm allen bolt. But none of that is your problem.


But, if you jumped the small solenoid connection and the engine cranked then I'd start by making sure you're getting 12V at the solenoid when the key is turned. Have someone turn key and use a test light or Voltohmeter or whatever- IF no 12V at that point then pull the knee panel from drivers side and have a look at the relay.
I can't be positive on an Allroad- but I bet it's the same and will have 53 on it. Top row, on the left.
I usually start with a test light- slide the relay out just enough to put the probe to the connections. When you turn the key one of those connections will light up 12V. And be dark when key not turned. (The shifter in P or N grounds that relay and completes the ignition circuit to let you start the car)
To bypass the relay (and the shifter interlock) you simply jump the two connections that are horizontal to each other with some 10/12g wire. If you really want- you can jump the starter directly at that relay connection I believe- one of those connections goes directly to the starter/solenoid- so if you applied 12v to it the starter would engage.

[MacFady]

Back from the dead, I hate when these threads end with no solution.

I have an automatic B6 1.8T USP Avant but this is the closest description I've found to what I'm experiencing, minus the tear down prior to symptoms. My car was running and starting fine, no issues at all. Jumped in one morning and no crank. I have all accessories, windows, lights, all my key FOBs work the door locks etc. (I tried starting with all FOBs, valet key etc.). I also have no priming from the fuel pump. So no crank at all (absolutely no sound, no click) and no prime sound from the pump. When I check the fuel rail I will get a little spurt and dribble out of the rail but that's it.

Battery is new and tests good. I checked all the relays but only in terms of "do they click with 12V", yes they do. I understand that is not fully testing the relay but worth mentioning. Fuses all test good with multi-meter. Symptoms are the same regardless of shifter position and I've tried jumping the interlock relay with no change. I changed the ignition switch with no change in symptoms. The crank position sensor was also changed (this was early on and I realize now not the issue).

I'll follow your steps to check the starter and solenoid, but is there something more direct I could expect it to be given that I don't hear a prime and don't appear to have fuel pressure at the rail either? I haven't really checked the fuel pump or the starter directly yet because out of the blue neither appear to work so I thought neither was likely to directly be the cause of my issue, that's why I jumped on the ignition switch once the relays checked out.

I'll admit I haven't checked the voltage directly at the relay plugs yet though. I have a voltmeter and a test light. What pins on what relays would be suggested to try for such an issue? I have the 1.8T wiring diagrams and relay diagrams but haven't had to trouble shoot electrical issues before so it's pretty foreign to me although I'm otherwise mechanically inclined. I can say that with the lower knee panel removed all the wiring and everything visually looks pristine, the ECU box is bone dry with no hint of moisture.

I guess I could also suspect a bad ground but wasn't sure where to start looking. I should mention that I can connect to the ECU with the Torque app so I assumed that meant the ECU had power.

Any help at all would be appreciated, I feel like I'm not getting anywhere with this.

[brokenwrench]

Without looking at your car myself I can only guess here, but check all your fuses first. Then check all the relays under the dash. Then check the clutch/neutral safety switch (don't know if your car is auto or manual). A faulty neutral switch will prevent the starter from engaging. There is a way to check with a DMM whether the switch is closing correctly or not, but I'm not familiar with the 1.8 wiring.

It's unusual for a switch to suddenly just die, but it's fairly common for electronic sensors to fail without warning. Unfortunately I don't know of any engine sensors which would prevent the starter from engaging, so my first suggestion is to check the engine status as thoroughly as possible. If the car is an automatic, maybe try starting with the shifter in N instead of P, I don't really know.....

[MacFady]

Thanks for the reply, sorry, I'll update my original post, I was outlining everything and should have mentioned that the car is an Automatic, the symptoms are the same regardless of shifter position and I tried jumping the terminals on the park/neutral interlock relay and nothing changed. I'm not throwing any codes.

[02 A6 2.7T]

I'll follow your steps to check the starter and solenoid, but is there something more direct I could expect it to be given that I don't hear a prime and don't appear to have fuel pressure at the rail either? I haven't really checked the fuel pump or the starter directly yet because out of the blue neither appear to work so I thought neither was likely to directly be the cause of my issue, that's why I jumped on the ignition switch once the relays checked out.

Check the voltage at the starter solenoid first as Bob mentioned in post#23 above. If there's no voltage at the spade terminal on the solenoid, use a remote starter switch from the battery + directly to the solenoid to see if it will crank. If it doesn't, the starter has failed.

[MacFady]

Just to update, I got as far as testing the "B" post on the starter for constant 12V, which it had. I then noticed that the small braided wire between the solenoid and starter looked toast, sure enough I could stick the end of a flat head screw driver right through it. Anyone ever had any luck replacing just the braided wire? I'm pretty sure the rest of the starter works fine, I didn't have any issue/sounds etc. leading up to this no crank.

[02 A6 2.7T]

Just to update, I got as far as testing the "B" post on the starter for constant 12V, which it had. I then noticed that the small braided wire between the solenoid and starter looked toast, sure enough I could stick the end of a flat head screw driver right through it. Anyone ever had any luck replacing just the braided wire? I'm pretty sure the rest of the starter works fine, I didn't have any issue/sounds etc. leading up to this no crank.

AFAIK, the braided wire is an integral part of the internal case winding and cannot be replaced separately. It is either corroded or was fried by an internal short in the winding. Likely time for a replacement starter ...

[MacFady]

OK, thanks for the reply. I ended up seeing some DIY's to replace the wire on other VW forums. I have to pull it anyway so I think I'll try the fix I saw and bench test it before buying a new starter.

[MacFady]

Just to follow-up, despite everything else I outlined above, I replaced the starter and the car fired right up.

[02 A6 2.7T]

Just to follow-up, despite everything else I outlined above, I replaced the starter and the car fired right up.

Awesome!