2.9 build keeps flooding....!!!

[Scotty_2.0]

Running out of patience trying to get my fresh 2.9 build started.... engine will not start/run and keeps flooding badly. At this point I've checked and tried just about everything. Each time I go to start the engine, it tries to fire and then stalls out. When I pull the plugs they're dripping and visible puddles can be seen on the top of each piston.

So far I've check the following:
- pulled the VC and verified engine timing is still bang on.
- checked spark strength on each coil.
- checked connections and measured resistance of the CTS, injectors, cam senosr, MAF, ISV (measured with a DMM at the ECU connector).
- removed the fuel rail and checked the spray pattern of each injector (going to recheck with actual fuel pressure).

New parts include plugs, wires, all coolant temp switches/sensors, 25L of fresh fuel in the tank, and a new IAT sensor. The engine will run briefly on starter fluid with the fuel pump relay out and the lines pinched.... any input is greatly appreciated.

Pic of the disaster...

[Eric D]

Do you remember replying in this thread?
http://forums.fourtitude.com/showthread.php?4825673

Do you happen to own a noid light?

I have a kit identical to this one.



Also in another thread, you claimed to have a TT chip, I'm not sure if this was before the 2.9L motor.
But was the vehicle running after the chip swap?

[Scotty_2.0]

Yeah I just re-read that thread... I'm definitely gonna pull the rail tomorrow and check for a possible leaky or faulty injector. I have two ECUs one with a custom TT chip the other stock. The same thing happens with both ECUs. I do have a noid light set, but what would I be looking for while using it...? Am I right to assume that since I have conclusively seen a good consistent spark I should have a proper injector pulse? I'm also going to check the injector wiring for any possible shorts to ground. Thanks

[Eric D]

Yes the noid light is used to check for injector pulse.

You don't want to see a solid light with key on, or cranking.

Before I forget, check your 42 pin round engine harness connector, perhaps a pin got bent.

[Scotty_2.0]

Alright, I'll check things out with the noid light tonight. I have had the 42 pin round connector off and checked for damage/corrosion - none found.

[Scotty_2.0]

Well... noid light in and I've got a solid light with the key on The light disappears if I unplug any of the other injectors. I tried the other ECU (Corrado with a custom TT chip) and it does not keep the light on solid with the key on. Both pulse while cranking though. Checked over the wiring and can't find anything out the ordinary. No shorts to ground or cross shorts. Originally when I first tried to start the car and it didn't fire I had the chipped ECU in. I'm tempted to slap the intake back in and try starting it again with the chipped ECU.

Not sure if it matters, but I also changed the engine harness (one that mounts with the engine) when I rebuilt the motor.....

[Eric D]

Check the ohms on your injectors.
The solid light indicates a short.

[Scotty_2.0]

Yeah I checked them, they're all sitting at 15.8-16ohms. Why would the light come on solid with one ecu and not the other...?

[Eric D]

That tells me the ecu injector driver may be shorted.

[Scotty_2.0]

Yeah, I'm pretty sure that's what it is. I measured the resistance from each injector ground wire back through the ECU to ground and they're all between 200-250ohms, which is a good enough ground to have the injectors switched on. The 200ohms goes open circuit the minute I disconnect the 68pin ECU connector. Gonna try it with the other ECU and re-check the resistance values to ground.

Thanks Eric

[Scotty_2.0]

Well I tried the other ECU and it didn't flood as badly, but it still quite rich and still won't run. Best I could manage was 6 seconds of stumbling/revving I think the problem may be that the other ECU I have is from a 95 Corrado that uses a 6pin MAF (021 906 258 DJ). The question now is what other ECU's can I use in place of the failed 95 Passat one I was using - 021 906 258 BS....?


EDIT: I've decided to just go ahead and replace the ECU harness that I have from the same corrado the ECU belongs to. This way at least everything will be from the same vehicle and may finally get this thing running.

[Scotty_2.0]

Almost too embarassed to say that this thing is still not running..... I've swapped out the entire harness so that all the electrics are from a 95 Corrado now. I've tried another hot wire MAF, cleaned and tried both my ISV's I have kicking around (one of which was in use before the rebuild).

The motor isn't flooding as badly as it was before with the wrong and possibly failed ECU, but still runs rich. The plugs aren't dripping like they were before but they're still very sooty. I have changed the plugs since the flooding issues just to be safe.

Most recently I've finally done what I should have done years ago and bought a VAG-COM. Only problem is I don't have a reliable base line to compare data with. I have however noticed some things that make me a little curious. For example, with my foot off the accel pedal the TPS angle shows about 11 degrees (same result with two different TPS's). Then to keep the engine running I have to keep the throttle angle at around 20-30 degrees. While the throttle is open though the ISV duty cycle hovers around 60-70%.....

Anyhow, I'm running out of ideas and am in desparate need of help. At the very least I need to get the engine broken in before the weather means I'll have to park it.

Gonna try the ECU from my friend's Corrado tomorrow......

[vdubxcrew]

I had a similar issue with my Corrado VR6 a while back. It would start up and run for about 6 seconds then stall. I found the problem to be a bad connection in the main harness barrell plug-in by the coilpack. Mine had some mild condensation in it. I took some electronic cleaner and sprayed it pretty good. Let it completely dry and plugged it back in snugly and whoo-la. Fixed my problem. So I would suggest checking over all your plug-ins for condensation or corrosion.

[Scotty_2.0]

I had a similar issue with my Corrado VR6 a while back. It would start up and run for about 6 seconds then stall. I found the problem to be a bad connection in the main harness barrell plug-in by the coilpack. Mine had some mild condensation in it. I took some electronic cleaner and sprayed it pretty good. Let it completely dry and plugged it back in snugly and whoo-la. Fixed my problem. So I would suggest checking over all your plug-ins for condensation or corrosion.

Good to know. I'll def be checking that connector a little closer. Last I checked there was no corrosion, but I'm gonna look a bit harder at all of them. May even just spray them with contact cleaner just in case.

Thanks for the reply

[Eric D]

Good to know. I'll def be checking that connector a little closer. Last I checked there was no corrosion, but I'm gonna look a bit harder at all of them. May even just spray them with contact cleaner just in case.

Thanks for the reply

Get some Stabilant 22A, it's made in Canada.
http://www.stabilant.com/

Or from VW, part number ZVW 186 001

[Scotty_2.0]

Get some Stabilant 22A, it's made in Canada.

Ahhh, I've still got some of that. Used to use it on airbag connectors when I was still on the bench @ BMW. Great for curing unwanted resistance issues.

[Scotty_2.0]

Tried a known good ECU from my friend's Corrado.... still no go. No change at all. Thankfully I'm off tomorrow so I've finally for some time to dig into the wiring. Time to make friends with my Fluke again...

[TBT-Syncro]

have you tried simply unhooking the maf sensor and trying to start it?

[Scotty_2.0]

have you tried simply unhooking the maf sensor and trying to start it?

Yeah, I did. Infact today I disconnected the MAF while it was sort of running at it died imediately. Whether it was already about to stall and the MAF disconnect was simply a coincidence I'm not sure....

I've fluked the harness to death and still come up with anything. Thought I had it licked when I noticed two large ground wire pins in the round 42-pin connector unlocked and sliding out slightly, but no. I've also extensively cleaned the 68-pin ECU connector, the round 42-pin engine connector and all the sensor connectors.

Realized the value of going OBDII when I saw the pitiful list of readings available to me and my OBD heap via my new vag-com.

With the exception of the knock sensors, I've now officially tried two of every sensor in this thing, no change in readings or performance... (MAF, ISV, TPS, ECT, IAT, Crank and cam sensors, and a coilpack).

[mk3pete]

could it simply just be a sticky relay somewhere?
i had my car off the road for 3 months a few years back after loosing my licence
deciding it would be a good idea to replace my heater core...
after everything was back together and i turned the key over, the horn was stuck on lol
ended up being a sticky relay

[Scotty_2.0]

Well.. the two relays I'm concerned about (ECU and fuel pump) are both new. The fuel pump relay was actually wrong. Didn't have any effect on my problem but the pump would stay on anytime the key was on rather than just while starting/running.

[Lukedub]

I'm sure you checked this already, but what's your fuel pressure like and is your fpr good?

[Scotty_2.0]

I'm sure you checked this already, but what's your fuel pressure like and is your fpr good?

Yeah I've got an inline FP guage at the side of the VC. I even tried a spare FPR (both of them were 4bar) I had from the original engine.... *sigh* Thanks though

[Scotty_2.0]

Some progress... tried my ECU in my friend's Corrado and it ran perfectly so the ECU is offically eliminated. Thoroughly cleaned the grounds on the intake manifold bracket and all the ones at the battery. I also ran a 4 guage cable from the lower intake directly to the negative battery post.... no change.

Are there anyother grounds to clean/check? Anything in the fuse panel......?

[mk3pete]

isnt obd2 3 bar??

[Scotty_2.0]

isnt obd2 3 bar??

Correct. Mine is OBDI though so 4 bar is the one I need. I did think about trying a 3 bar, but I did already tried limiting flow by pinching the supply line and watching the pressure in the rail. Didn't make a difference.

[vr-vagman]

You can check your vacuum connection between FPR and intlet manifold. If it is flooded, most probably your FPR is leaking stright in the mani due to the vacuum inside.

[Scotty_2.0]

You can check your vacuum connection between FPR and intlet manifold. If it is flooded, most probably your FPR is leaking stright in the mani due to the vacuum inside.

It does smell like fuel inside, but the whole intake does also since it's been running so rich. no drips though. It's pretty much the same with both FPR's that I tried.

[vr-vagman]

Then just lеаve it unconnected to the mani, block the vac orifice of the manifold and start the bastard.

[Scotty_2.0]

Tried running it with the vac line off the FPR, no change. Also jumped the fuel pump relay and applied vacuum to the FRP with a hand vacuum pump and it held 20in of vacuum and no fuel could be seen exiting through the clear vacuum pump hose.

Trying to locate a 2x2 vagcom adaptor cable so I can compare the running data with my friend's Corrado.

[Das.Rado]

Im not sure if you've done this or not, but have you taken your fuel rail off and dispensed 30 seconds worth of fuel into a measuring jug to see how much comes out. I beleive in a 30sec period 750mL is the minimum amount, so if youre bang on 750mL, i would check spark and try and figure out why spark cant keep up to the fuel. If you are getting a **** tonne more than 750mL id check your fuel pressure regulator and maybe even the air intake readings via "VAGCOM Measuring Blocks". (TANGENT: im not 100% sure if 750mL for 30 seconds is right so you should probably check that first.)

If you are getting the correct amount of fuel and i beleive you said you are getting spark i suggest checking your spark plug gap and make sure thats spot on, that can cause performance mess ups pretty good.

Anyways i hope something i have mentioned here helps.

[vr-vagman]

Im not sure if you've done this or not, but have you taken your fuel rail off and dispensed 30 seconds worth of fuel into a measuring jug to see how much comes out. I beleive in a 30sec period 750mL is the minimum amount, so if youre bang on 750mL, i would check spark and try and figure out why spark cant keep up to the fuel. If you are getting a **** tonne more than 750mL id check your fuel pressure regulator and maybe even the air intake readings via "VAGCOM Measuring Blocks". (TANGENT: im not 100% sure if 750mL for 30 seconds is right so you should probably check that first.)

If you are getting the correct amount of fuel and i beleive you said you are getting spark i suggest checking your spark plug gap and make sure thats spot on, that can cause performance mess ups pretty good.

Anyways i hope something i have mentioned here helps.

According VAG's manual these injectors should flow between 90 and 130ml/30sec each. I doubt it is the pressure.
Leaking injecrorS! - not really. I would find a scope and check inj pulse width and number of injections per cycle. Also the G28/G40 signals and their synchronization.

[Scotty_2.0]

Well it appears that there is def a timing issue. The vagcom shows 20-30 degrees BTDC of timing on the ignition.....? Last night I even removed the cam and crank sensors to check for the correct placement of the trigger magnet and reluctor wheel. I don't know how this is possible to be off on ignition timing while the mechanical timing seems bang on.

Tell me if this is correct: I turn the engine until cylinder 1 comes up on compression and then install a spring loaded plunger into the spark plug hole and turn the engine until the number 1 piston tops out (TDC). When it does, the cam plate slides smoothly in the the camshafts.... am I missing something?

[elief1]

Well it appears that there is def a timing issue. The vagcom shows 20-30 degrees BTDC of timing on the ignition.....?

are these values at idle???
try to disconnect the 2 knock sensors and check again with vag-com,
i am interested to know the solution for your problem.
good luck

Elie.

[Scotty_2.0]

Yeah, they're kind of at idle. Since the idle won't stabilize those timing readings are happening from 700-1800 RPM while the holding the throttle at about 30 degrees just to keep the engine running long enough to log the data (closed = 11 degrees).