Cummins 4BT & Diesel Conversions Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hi,

I am hoping someone here can answer this for me! Does the 4HE1 pump have a flyweight advance mechanism in the injection pump drive gear, or is the timing advance handled by the Zexel MITICS system? This would be for the pumps that have the single wire timing advance mechanism on the front (see this Ebay listing - Zexel TICS Fuel Injection Pump 107492-1130 for Isuzu 4HE1-X Engine 8972121880 | eBay), as opposed to the later pumps with the MD-TICS system, which has a 6 wire plug.

The 4HE1 pump calibration information for the early pumps does show a 4 or 5 degree advance based on RPM, but the manual also says that the MITICS is mechanical, works of the governor (RLD-M type), and handles pre-stroke and timing. The manual also says that the timing solenoid only gets 12V on startup.

I am trying to see if I can build a hybrid MITICS pump for my Fuso swapped cruiser using a donor pump from a 4HE1 application, but info is scarce, and cores are not cheap. If the gear is solid (which it certainly looks to be), that would mean that the timing advance would be located elsewhere (and my evil plan will work).

Thanks!
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #2 ·
Looks like this is a mystery - I think I found the Zexel MITICS theory and servicing manual on ebay, will update this once I know how the system works, but it definitely appears to be in the governor.

Thanks
 

·
Registered
Joined
·
1 Posts
Hey mate do you have anymore information on how the ticks pump works ?

I have an older 4he1 that is purely mechanical and then also a newer 4he1 that has the timing plunger aswell as a bunch of diaphragms and vacuum solenoids that adjust things aswell


Dis you manage to find a manual for the zexel pump?


Thanks
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #4 ·
Yes I did, it was tough to find, will post more information soon. The MITICS engines are fully mechanical timing in the governor, the MD-TICS are electronic. I am very impressed by this system. There are also some AD-based pumps used in other markets besides NA, Australia I think.
 
1 - 4 of 4 Posts
Top