w124 - coupes HFM or CIS motors? - PeachParts Mercedes-Benz Forum

mushedroom · #1 05-29-2002, 01:16 PM

can someone please explain or shed some light as to what HFM and CIS motors are?
thanks

Potomac Pat · #2 05-29-2002, 04:55 PM

I believe that the HFM = electronic fuel injection opposed to the CIS = continuous injection system. Any other specifics, I am sure that someone else here can elaborate some more on these different set-ups.

mushedroom · #3 05-29-2002, 06:57 PM

so i wonder which is better?
hmmm

Ashman · #4 05-29-2002, 09:48 PM

the 3.2 litre version of the m104 is by far the best one, based on power and torque.

The 3.0 24 valve m104 engine is also nice, but torque is lower than hp ratings as far as I know.

Anything else in a CE would be an M103 engine. less hp and valves than m104 3.0 litre engine.

If I could choose, I'd take the 3.2

I have the 3.0 M104 24 valve, its plenty peppy for me, but if I could add lets say 30lbs of torque for cheap, I'd be satisfied fully.

Alon

mushedroom · #5 05-30-2002, 02:29 PM

hey ash,
thanks...
cause whatever you say about your car goes exactly the same for mine...
i think we're pretty mush the only ones with 92' 300CE's too...
if i read right...production numbers total were 1836 units...i'm not sure how many were sent to the US and how many stayed in Germany....

#6 05-30-2002, 03:16 PM

mushedroom,

You'd be surprised how many 300CE's are out here. Check out this thread. Check out the 300CE roll call.

In fact, I'll add your name to it.

Phil

mushedroom · #7 05-30-2002, 03:18 PM

hey thanks for the roll call thread, but where's the thread?

#8 05-30-2002, 03:22 PM

300CE/E320 Coupe owners Roll Call!

Try this.

Gilly · #9 05-30-2002, 10:50 PM

CIS is Continuous Injection System, It has a fuel distributor and injectors, but all the injectors operate continuously, kind of like a GM (or other) throttle body injection, EXCEPT that each cylinder has it's own injector, and it's injected at the end of the intake manifold runner, giving a much better, even distribution to each cylinder.
HFM is Hot Film Management, before this was LH, which is "Luft Hotwire". Both are indications of the type of Mass Airflow Sensors the systems used (The first, LH, was a measurement taken by reading resistance output, in effect, of an electrically heated wire in the intake airstream. Hot Film was similar, but used a heated section of a film-like "membrane" material). Either one of these is superior to CIS injection. These systems are both SFI (sequential fuel injection) systems. That means that the fuel spray is not continuous, but injects fuel at the appropriate, sequential order (per the firing order) to deliver fuel at the correct time. These systems all had seperate ignition control modules. What MB uses today in most of the gas engines are called ME management systems, which have the ignition systems integrated into the engine control module. They are still in the most basic sense "HFM" systems, as the Hot Film Mass Airflow sensor is still utilized.
Gilly

Michael · #10 05-31-2002, 08:26 AM

Thanks, Gilly

mushedroom · #11 05-31-2002, 12:49 PM

thanks gilly...
so in other words... my CIS 300CE sucks...
ugh

thanks for the info though really was helpful

Potomac Pat · #12 05-31-2002, 01:19 PM

I wouldn't say that your M104.980 motor sucks. It is more a prference thing IMO. The 104.980 does however make a converted 190E fly, less the wings of course.

ke6dcj · #13 05-31-2002, 09:29 PM

It's incredible what going to a better electronic fuel-management (EFM) system can do, esp. across the Rev range.

The HFM AMG'd C36 engine from 1995-1996 but out about 268HP and 270 ft-lbs torque; in 1997 MB installed ME (Motoronic) and power and torque is now 278HP and 280 ft-lbs. torque.

I believe when Carlos Piaad installed a 1995 C36 into his 190E-16v chassis, he went to an Electromotive TEC-II EFM, and got over 350HP and 320 ft-lbs of torque (unfortunately he was forced to sell the car).

Amazing . . .

Yes, you can retrofit one of these, but it is costly. Figure $2-3K parts, $1-2K to install.

:-) neil
1988 360TE AMG
1993 500E