Mk2 Gti 1z conversion thread

I know it sounds stupid but...

have you got +12v to the fuel stop solenoid? (or is the solenoid stuck in the closed position??)

no fuel & no start :-(

I had this happen to my B3 a few weeks ago, fine the previous night, early morning to comute to work & no start...
spent ages finding the problem, $15 worth of new solenoid later & all good

Rich.

I'm not ready to give up on the FCS yet as it does click and some fuel gets through.
After further investigation not only does the voltage to the fuel cut off valve Fluctuate but I have quite a range with battery voltage when cranking.

This makes me think that my battery is on it's last legs of course it's also a group 41 battery and I know the b4s require a group 49 battery. We're talkjg 12 V at the start of the cranking and then after two seconds or so of cranking we're looking at three sometimes 4 V or all over the place, this makes me wonder if the fuel cut off valve is actually also jumping around and never quite letting enough fuel through and therefore no start. I gravity fed the injection pump earlier this afternoon in hopes that maybe there was a problem with the delivery it up to the filter or some kind of problem previous on the line but nothing changed.
I also tried to loosen all the IP mounting bolts and shift the whole assembly to perhaps adjust timing. No dice. Tomorrow I'm going to snag a new battery and see what's what

bblume said:

I'm not ready to give up on the FCS yet as it does click and some fuel gets through.
After further investigation not only does the voltage to the fuel cut off valve Fluctuate but I have quite a range with battery voltage when cranking.

This makes me think that my battery is on it's last legs of course it's also a group 41 battery and I know the b4s require a group 49 battery. We're talkjg 12 V at the start of the cranking and then after two seconds or so of cranking we're looking at three sometimes 4 V or all over the place, this makes me wonder if the fuel cut off valve is actually also jumping around and never quite letting enough fuel through and therefore no start. I gravity fed the injection pump earlier this afternoon in hopes that maybe there was a problem with the delivery it up to the filter or some kind of problem previous on the line but nothing changed.
I also tried to loosen all the IP mounting bolts and shift the whole assembly to perhaps adjust timing. No dice. Tomorrow I'm going to snag a new battery and see what's what

Click to expand...

That's what I was going to ask a while back when you mentioned that you had fluctuating readings while you were cranking. I would probably put your existing battery on a trickle charger or at a 2amp charge (or less) for a couple days and get it back up to snuff.

It used to be that you could activate the pump stop solenoid (FCS) with a nine volt battery however I don't know if it can be done that way any longer although I suspect it can.

The starter takes a lot of power so the stop solenoid must be able to remain open while cranking with voltage dropping. If the stop solenoid had to have 12v there's a chance it wouldn't remain open long enough to actually get the car running.

Steve

The stop solenoid itself will still open with 9V but I'm not so sure about the ECU...

vanbcguy said:

The stop solenoid itself will still open with 9V but I'm not so sure about the ECU...

Click to expand...

True...hadn't considered that but I think you're correct. Best to have a good fully charged battery for getting it going I think.

Steve

Zed. said:

I know it sounds stupid but...

have you got +12v to the fuel stop solenoid? (or is the solenoid stuck in the closed position??)

no fuel & no start :-(

I had this happen to my B3 a few weeks ago, fine the previous night, early morning to comute to work & no start...
spent ages finding the problem, $15 worth of new solenoid later & all good

Rich.

Click to expand...

Where'd you get a n109 for $15???

Suppose there's pricing differences as I'm 2000 miles east of you
The stop solenoid is as used on landrover pumps, £8 so nice & cheap

http://www.ebay.co.uk/itm/251650065561?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT as an example (sorry, just did an online £-$ converter & it says $10.79!!)

That said, I buy parts from the U.S. and after postage it's cheaper than here in Britain


Rich.

I doubt it's your N109. Looked like this car was being built at a "shop", a big advantage over those who have built them in the dirt, wonder what the problem is.

GTiTDi said:

I doubt it's your N109. Looked like this car was being built at a "shop", a big advantage over those who have built them in the dirt, wonder what the problem is.

Click to expand...

Yes...it's in the auto shop at the school where I work...

Could the n108 be causing these problems then??

Double post for more help!!!
��
I've got the 01269 code. N108 (open or short to ground). I've got continuity from pin to pin on the n108 itself (I think that means it's good). I've got continuity from the n108 plug to pin 51. The other wire (if I'm reading right) gets to the n18 (egr ). I've got 10+ohms of resistance to that wire. And no continuity from the n18 to pin 25 in the Ecu. The wiring diagram looks as though this connection is a direct one???

I'm in dire need here of some guidance...this thing cranks but won't start. I've got voltage loss to n109 after a second or two of turning the key. And it drops to nearly 0 voltage??? Even when cranking!!

Barely a dribble of fuel comes out when I crack the lines and crank. Just at loss here?

Thanks in advance for your help.

As far as your fuel, it sounds like you still have air in your lines, plus check to make sure you have no breaks in your lines where your sucking air, when I crack my lines fuel will hit the bottom of my hood

Thanks for,the suggestion...I don't think its my lines leading up,to the filte because I gravity fed it straight out of the fuel can the other day with the same result---no,start and no smoke. I did this after Mitty vaccing the IP...even after that and cracking the lines to,bleed I still only get a dribble.

I am down to two ideas: Purchase a proper group 49 battery. (I am trickle charging my mk2 16v battery now and may give it a few more cranks).

OR/AND
Swap in a known working relay 109. (I'm only thinking this because of the voltage drop that occurs in the n109).

If know other clues arise or ideas appear...I suppose I'm towing it to a guru???

Do you have a black or grey 109 relay? Do you have a substitute that you can use for testing?

Give the battery a good charge and see what that does before taking it to someone to iron out this problem. What group battery are you trying to use now and how old is it?

I've been going over this in my head for a while trying to come up with a reason why you're having trouble and I haven't been able to bring anything to mind very easily.

Steve

Thanks for thinking of me!
The 109 grey and it came from the passat donor tdi
I do have a buddy nearby that has one. Probably try next week
Charging the battery now. Try that before a new battery
I've got a group 41 battery with 780 CA
It's not more than a year or two old but it's been sitting since I drove the Gti into the shop
Back in early DEC.
I guess I'm just confused as to what would 'tell' the n109 to switch off (even when cranking) it's also difficult to understand since the n108 is throwing the code.

:::::.

bblume said:

Thanks for thinking of me!
The 109 grey and it came from the passat donor tdi
I do have a buddy nearby that has one. Probably try next week
Charging the battery now. Try that before a new battery
I've got a group 41 battery with 780 CA
It's not more than a year or two old but it's been sitting since I drove the Gti into the shop
Back in early DEC.
I guess I'm just confused as to what would 'tell' the n109 to switch off (even when cranking) it's also difficult to understand since the n108 is throwing the code.

Click to expand...

That relay can get funky. One minute fine the next not good. Since you have the grey one I wouldn't at first consider that to be a problem but maybe since this is a conversion it would be good to rule it out.

The battery doesn't sound like it should be the problem, even having not been used since December unless it's got a bad cell or something, which it doesn't sound like it has. I'm running way older batteries in my vehicles but I do maintenance charges on them during the year at least once just to make sure they're ok. I think the battery in the Mk3 is from 2007 and that's probably the newest...haha. No problems though so far. I'm also still running the factory installed black 109 relay although I carry a grey one with me just in case something pops up.

So let me ask this, your harness is all buttoned up and everything seems to be connected? Nothing left undone under there that might be an issue? Grounds at the block are cleaned? What did you do with the grounds under the battery tray from the donor? You've gone back and rechecked your electrical connections so you know they're attached to the correct devices?

My biggest concern with my conversion in the wiring department is leaving something out or failing to get the Mk3 integrated with the B3 harness adequately. I guess I'll find out eventually.

I'll be giving this more thought.

Steve

bblume said:

Thanks for thinking of me!
The 109 grey and it came from the passat donor tdi
I do have a buddy nearby that has one. Probably try next week
Charging the battery now. Try that before a new battery
I've got a group 41 battery with 780 CA
It's not more than a year or two old but it's been sitting since I drove the Gti into the shop
Back in early DEC.
I guess I'm just confused as to what would 'tell' the n109 to switch off (even when cranking) it's also difficult to understand since the n108 is throwing the code.

Click to expand...

Abacus posted this in another thread where the owner questioned relay 109 problem. If the GP light comes on for a few seconds when you turn on the key then it's not a 109 problem. If the GP light does not come on when the key is turned on then it could be a relay 109 issue.

Steve

get a decent battery and a jump pack and crank the hell out of it with the lines cracked loose...this really shouldn't be so difficult.

GTiTDi said:

get a decent battery and a jump pack and crank the hell out of it with the lines cracked loose...this really shouldn't be so difficult.

Click to expand...

I've done this already a couple different times (with and without the pump primed).
No more than a dribble is getting out from the lines...

I agree this shouldnt be difficult, but something is telling the n109 to cutoff fuel???

then disconnect the lead to it and energize it with a jumper

Take a look at this thread and see if you can't find something in the same vicinity that might be causing your situation.

Steve

GTiTDi said:

then disconnect the lead to it and energize it with a jumper

Click to expand...

I like this idea.

I had the shop instructor try this many weeks ago, of course he jumped it withou disconnecting the wires going back to the ecu and smoked a few wires when the voltage seemed to go back through the wiring. I have since repaired/replaced these wires, but haven't tried to jumper the n109 since. I suppose when I get some time to work I'll simply remove the wire that attaches to the nut on top and jumper it directly from the battery while cranking.
It may stsrt it but it won't solve the problem of the ecu killing the n109 right away after starting....but it would be progress.

Anyways, good idea. Thx!!!. I'm open to all avenues at this point.

As for the thread you've posted Steve, I'll look into that too...thx!

wow sounds like the "instructor" might have smoked your ecu as well...damn

You might want to check the ecu. If you smoked some wires you may have damaged the ecu

Well it still communicates with vcds. Is there any other way to confirm its functionality ?

It may communicate but it doesn't communicate with everything may be just one place in ecu not working

^^^if this is the case, would it be beyond repair? Would the damage be visible on the ecu board?

Well its easier to just find or borrow one if you could ...it could be hard to see or it could stick out like a sore thumb

vw_nut said:

Well its easier to just find or borrow one if you could ...it could be hard to see or it could stick out like a sore thumb

Click to expand...

Gotcha
Haven't had time to even look at the gti
The soccer season has begun in Colo.

But was going to try today...any idea what kind of voltage the n108 gets?
Will jumping it to battery power be okay?

Progress: Replaced relay 109 and the n109 is now staying open. Cracked the fuel lines while cranking and had spurting fuel--no dribbling fuel.

Still no start though, My guess is either too much air in the fuel (stopping the injectors from popping) or timing is an issue. No smoke on cranking yet so to me that means the injectors aren't opening.

Going to try a gravity feed or even the methodical process of cracking each line then closing?? If this stuff fails I'll be retiming I guess.