1600i Digifant Fuel Injection Test Port Standard/Thread Size

[phade]

Hi everyone,

I have just bought Sealey's VSE211 fuel injection test kit, but unfortunately I found out that the 1600i doesn't use a standard Schrader test port.

Does anyone know what standard or thread size the 1600i Digifant fuel injection test port uses? (I can't find the VAG 1318 fuel pressure test kit for sale anywhere).

Thankyou everyone in advance,

Phil

[Manfred]

Hello Phil,
i didn't forgot this question. But till now i had no answer and don't know the size of this adapter.
Since 3 weeks i own a org. 1600i. But he has big problems with the first start every day. He starts for a few seconds and runs normal. But then either stops or runs like a old one cylinder machine.
So i tried many things and changed nearly everything wich is changeable.
Nothing helps.
So i thought its necessary to check fuel-pressure and volume.
To do this i found a very quick way. It looks like a one-way tool.
I got this tipp from Max, he is in the registry with N 34

Its easier to use pictures for me.

I bought this pice for 5.60 Euro


Than i drilled it up 9.5mm. 9mm is to less. Maybe it works also with 10mm
You see the drilled piece on the left side


Here you see this part connected to the 1600i fuel pressure port.
It's a little bit tricky, if it is to far on the port, than you can't secure it, if it is to low, the valve don't switch.


Next and last step in building this tool was to plug a hose.


Ok, i was ready to make my tests.


To check fuelpressure, the car should have 2,5 bar in idle-mode. If you take off the small white hose to the fuel pressure regulator, you should get about 3 bar.
Now you switch off the engine and after 10 minutes there should be still 2 bar.
But as my engine didn't work like it should, i make the test with with my ecu-box, there i connected pin 16 and 3, then only the fuelpump runs.

I got 3 bar when the pump was running. Now i simulated the idle mode with the usage of a disposable syringe (hope the is the correct word for the green piece)
I got 2,5 bar and could here the fuel presusre regulator working when i played with disposable syringe.
After 10 minutes i also had mor then 2 bar. So that was ok.
For the volume test i removed the clamp from the hose and switched on the fuel pump for excatly 10 seconds. I should have got 350 ml of gas.
But it had been only about 170 ml. So i think i know where i had to search tomorrow. I changed the fuel filter as one of my first actions.

Hope this will help a little

I wish you a merry christmas and a happy new year
Manfred

_________________
1600i Register N° 001

[phade]

HIya Manfred,

Thankyou for the tip I'll have to find an old footpump and modify my fuel pressure test kit to check the fuel pressure just in case. I have ordered a new fuel pressure regulator some time ago (from VW classicparts) just in case it was that, but it seems to be more like an electronic fault (eg. the engine almost cut out for a few seconds then ran ok again for ages). I have already replaced the following so far:-

- Ignition leads
- ECU relay
- Fuel pump relay
- Fuel pump
- Fuel filter
- Distributor (the hall sender was originally faulty as well, I found that out when I wiggled it's socket with a pair of pliers)
- Ignition transformer

I have also suspected the socket on NTC2 (the engine oil temperature sender) may also be causing this intermittant fault. I had another look at that socket last night and I was able to move it around by at least 5mm, which I think is very loose. The connections on NTC2 (just like on the ignition transformer) are also a bit corroded. I have ordered a replacement one of those as well just in case.

I had also checked the condition of NTC1 (air intake temperature sender) as well, but the socket on that sender looks ok (hardly any movement at all).

I quickly started up my car tonight after I had replaced the ignition transformer last night and it seems to run ok at idle (I couldn't run it for very long as it was too late at night), so hopefully I'll be able to run the engine until it's warm to see if there are any problems.

I'm using my campervan at the moment (uses quite a lot more petrol than my mexican beetle, but it's very comfortable to drive), so hopefully I'll be able to fix my mexican beetle and spend less money on petrol again

Anyway I hope that you are all well, and have a happy christmas and have a great new year

Good luck with your mexican beetle.

Thankyou for your help ,

Phil

[phade]

Hi everyone,

I have just tried Manfred's tip on using the hose (and tyre connector) of a foot pump and it works a treat I got a brand new foot pump today, cut the hose off and drilled out the tyre connector's hole to 3/8" (I didn't have a 9.5mm drill, but it's very close).

I then connected the hose to one of the adaptors with my Sealey VSE211 fuel injection pressure test set and measured the fuel pressure.

Initially the fuel pressure was 3.0 bar (engine just started up) and dropped to 2.5 bar as the engine warmed up. I then disconnected the vacuum hose from the inlet manifold to the fuel pressure regulator and the fuel pressure rose to 3.0 bar.

I then switched off the engine and waited for just over 10 minutes. The fuel pressure did drop, but not nearly enough. It remained at 2.7 bar, where it should be at about 2.0 bar. I think in this case it's the fuel pressure regulator as well as NTC2 (engine oil temperature sender).

Hopefully, I will be able to replace both of them in the New Year and I hope that my mexican beetle will run properly again

I have also taken photos of my fuel pump replacement and fuel pressure test procedure and hope to document it at some point for the 1600i website.

Thank you Manfred for your help and thank you everyone who has read this topic as well.

Cheers,

Phil

[Manfred]

Hello Phil,
what you describe sounds good.
But i think when i took a look at the 1600i manual, that it should be at least 2 bar. If it is more its also ok, only if it is less it's not ok.
And i don't think that the engine temperature sensor has any influence on the fuel pressure.
But if you could, try also to measure the tranported fuel volume within 10 seconds running of the fuel pump.

regards
Manfred

_________________
1600i Register N° 001

[phade]

Hiya Manfred,

I have already replaced the fuel pump (that's one of the first things I did) and sadly it didn't cure my car's intermittant misfire problem.

I only suspected the fuel pressure regulator yesterday since my 1600i booklet said that the fuel pressure should lie at about 2 bar. However my 1600i booklet also said that if the fuel pressure doesn't drop then the fuel pressure regulator should be replaced, therefore I guess from what you mentioned yesterday that the fuel pressure regulator is in fact working properly.

I suspected NTC2 since it's socket was falling to bits (the plastic part of it is very loose to say the least). Hopefully I'll be getting a new one of those in the post just after New Year's and replace the old one to see if my car's intermittant misfire has stopped or not.

Anyway I hope that you are all well and have a merry christmas and have a great new year

Best Regards,

Phil

[Manfred]

Hello Phil,
even the English manual says "After 10 minutes the remaining pressure must lie at min. 2.0 bar.
So your measurement shows, that the regulator should be ok.

_________________
1600i Register N° 001

[phade]

Hiya Manfred,

I didn't read that bit properly (min. 2.0 bar), thank you for telling me about that At least that's one less thing to replace on my car

Cheers,

Phil