4bt IP Questions

[JaysinSpaceman]

Ok, so I have my 4bt pump Bosch # 0 460 424 045 and I have a couple of questions. There is a lever on the side of the LDA top and I can't seem to find any reference to it in the Bosch VE book, what is it? And second there is a mechanism attached to the timing piston cover on the same side, is this an hydraulic cold start device? It looks correct for the description in the VE book but I just want to be sure. Here is a picture

 

[Dougalicious]

www.4btswaps.com

Those guys can tell you anything you need to know about this engine.

 

[JaysinSpaceman]

Doug, Thanx for the link. The reason I asked here is that I will be going on a mTDI and others have used this pump to good success.

I did figure out what the lever on the side is for, It is the mechanical shut-off for the engine. It seems that this pump has both the electric solenoid shut-off and this mech. shut-off. Go figure.

 

[DPM]

Same with older Peugeots, a lever on the rear face of the pump. Also means additional adjustments for "residual fuel/ anti-stall" rather than just an idle speed.
The hydraulic whatsit is certainly a thermo-hydraulic advance.

 

[JaysinSpaceman]

DPM, What are the "residual fuel/anti-stall" you are speaking of? It is not something that I find in the VE book. Are these positives or negatives, beneficial to tuning or just more complexity?

Thanx
Jaysin

 

[DPM]

If memory serves, it moves one of the components of the governor lever outside the case, and it's function is to make the rate-of-deceleration adjustable.
Too little antistall and revs drop like a stone, falling under idle before the governor has a chance to catch up
Too much antistall and the engine will take numbers of seconds to drift back down to idle.

Means you can fine-tune the pedal response to reduce bucking.

 

[JaysinSpaceman]

Cool, thanx DPM. Sounds like that would be a good thing, especially in a pickup. I'll have to check it all out once I get the pump apart for the modifications it needs.

 

[westyman]

So Jason, did you get my note over on the GTD forum?

I gave you the specifics on what works to get the rpms and throttle travel changes for the 4BT pump. I'm no longer a member there so can send/receive messages there.

The little lever on the outside of the case is a mechanical throttle shutoff.

Also, in case nobody has mentioned yet, you'll need a re-machined 1.6 pulley or flipped and machined ALH pully/hub combo to fit the 4BT to your TDI.

Karl

 

[big specht]

Do you have any pics of re-machined pulley I have one that I'm planing on doing that to and was thinking of useing a 4bt pump

 

[RoundHouse]

If memory serves, it moves one of the components of the governor lever outside the case, and it's function is to make the rate-of-deceleration adjustable.
Too little antistall and revs drop like a stone, falling under idle before the governor has a chance to catch up
Too much antistall and the engine will take numbers of seconds to drift back down to idle.

Means you can fine-tune the pedal response to reduce bucking.

That lever is some type of overspeed shutdown or something, not exactly sure.

We rented a platform lift with a 4bt in it, and it quit running, with someone 60 feet in the air, had to get the fire dept to get him down,

the service truck the rental place sent out, just flipped the lever back over and it started right up.

 

[red golf tdi]

So what is the "mechanism attached to the timing piston cover" ???

I have a 1986 Jetta NA without it, and a 1989 Jetta NA with it. Both ME engine codes.

 

[JaysinSpaceman]

It is a electromechanical thermostatic cold start device that retards the injection for ease of starting.

Jaysin