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Author Topic: 1.6td fuel screw question  (Read 1358 times)

December 05, 2022, 10:19:31 am

33B

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1.6td fuel screw question
« on: December 05, 2022, 10:19:31 am »
Okay so my NA to TD engine died (pison rings no longer exist). So I swapped a JR td. Good engine runs nicely. But I want to get boost like before 1.5 bar max. So I started to screw in the fuel screw but its auto revving.
I screwed it in maybe half a turn and as soon as you touch the gas pedal it starts self revving, also rev hang at 3k. Why is that?
Pump is timed correctly by myself at 1.02mm as bentley's book says.


1987 Passat B2 (33B)- 1.6TD JR, Audi 80 b4 front suspension and power steering. 280mm brake discs with 54mm calipers front. Rear MK3 disc setup with golf mk5 calipers.

Reply #1December 06, 2022, 12:25:24 am

fatmobile

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Re: 1.6td fuel screw question
« Reply #1 on: December 06, 2022, 12:25:24 am »
My condolences.

  Half a turn is pretty far.
Does it still have the limiting collar?
 That's what happens when you turn the fuel up too far.
 The rpms hangs and or rise.

 Or it could be a bad spray from the injectors. A pissing injector will partially burn, then have fuel left over the next time around.
Smoking white?
Tornado red, '91 Golf 4 door,
with a re-ringed, '84 quantum, turbo diesel, MD block

Reply #2December 06, 2022, 06:34:23 am

33B

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Re: 1.6td fuel screw question
« Reply #2 on: December 06, 2022, 06:34:23 am »
Thank you, your so kind.

No white smoke. It was turned to the collar. I guess the previous owner did that. And yesterday i removed it and it self revved. But the rev hang was there before i touched it.
1987 Passat B2 (33B)- 1.6TD JR, Audi 80 b4 front suspension and power steering. 280mm brake discs with 54mm calipers front. Rear MK3 disc setup with golf mk5 calipers.

Reply #3December 06, 2022, 08:44:13 am

Tomoturbo55

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Re: 1.6td fuel screw question
« Reply #3 on: December 06, 2022, 08:44:13 am »
It's probably the stretched choke spring inside the pump, a small spring that is attached to throttle.
« Last Edit: December 06, 2022, 10:28:41 pm by ORCoaster »

Reply #4December 07, 2022, 12:49:17 am

fatmobile

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Re: 1.6td fuel screw question
« Reply #4 on: December 07, 2022, 12:49:17 am »
A "choke" spring?
 There is a spring going from the cold start to the "accelerator" inside the pump,..
 on pumps with the increased RPM tied to the cold start lever. The extra stuff on the back of some pumps.
 Otherwise there is no "choke" or springs connecting the cold start to the levers inside.

So you removed the limiting collar?
 That will just allow you to have more rpms hang as it allows even more adjustment in that direction.
Tornado red, '91 Golf 4 door,
with a re-ringed, '84 quantum, turbo diesel, MD block

Reply #5December 07, 2022, 05:15:30 am

33B

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Re: 1.6td fuel screw question
« Reply #5 on: December 07, 2022, 05:15:30 am »
I don't have that RPM increase thing.

Anyway I fixed it. Screwed it out a bit more no more rev hang. Why I couldn't get more boost, well I forgot I reset the wastegate screw when i took out the exhaust manifold....... Tweaked the LDA a bit and now it's running like a dream.

I like this pump a lot. You can tweak almost anything on/off boost related. I did disassemble it last week, vane pump was stuck. Cleaned it out and replaced the gaskets. I love having an original TD engine so far. No smoke before boost, lower EGTs with the same boost(could be that the previous engine IP was not timed right, bought the tool 3 days before it died). Running 600C in 3gear 1.5bar, as before i was hitting almost 800C.

And now having a hydro engine I can do the 1.9td head gasket and also a 1.9td head. That will come at a future date. For now I'm done freezing my *** off in a cold garage.

Thank you fatmobile for another great input!
1987 Passat B2 (33B)- 1.6TD JR, Audi 80 b4 front suspension and power steering. 280mm brake discs with 54mm calipers front. Rear MK3 disc setup with golf mk5 calipers.

Reply #6December 07, 2022, 11:02:47 am

Tomoturbo55

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Re: 1.6td fuel screw question
« Reply #6 on: December 07, 2022, 11:02:47 am »
A "choke" spring?
 There is a spring going from the cold start to the "accelerator" inside the pump,..
 on pumps with the increased RPM tied to the cold start lever. The extra stuff on the back of some pumps.
 Otherwise there is no "choke" or springs connecting the cold start to the levers inside.

So you removed the limiting collar?
 That will just allow you to have more rpms hang as it allows even more adjustment in that direction.
Yes thats What i tought.

 

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