1992 300E 3.0 -165 k miles
Following have been replaced : suppressor shield under rotor ,distributor cap and rotor-wires are recent .Lubed linkage and checked cable

Engine will not rev past idle at times, possibly heat related. Initially the car would display this symptom and then perform normally . It is like putting your foot into air the as it does not respond. Never stalls ...once the revs went crazy near red line burning gravel...

Next two guesses are rear Crank angle sensor and coil. Ideas ?

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92 300e 205 k miles decent -wife's ride
91 300 TE many upgrades and very clean-Junk yard rescue ( son's "hot rod")
68 250 s Low rust great shape
91 300e 236k ( rear ended and sheared metal subframe mounts /sway bar )
85 300TD 310k

Below have moved on
77 300d 36k miles one elderly owner! Now in Ca fully restored
79 300 sd 49k miles( time capsule clean )sold and still in ohio
66 230s new at factory "das boot" gone.
93 190e 2.6 crunched-hard no injuries
69 220d rusted away

If the engine speed isn't changing and the engine isn't stalling, it isn't fuel OR spark. With the throttle plate tipped in, if they aren't varying, the engine will stall. I'd be looking at linkages for something loose, broken, or worn to the point you get intermittent operation.

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

This car likely has the sort of drive by wire throttle where a linkage and a electric motor operate the throttle blade.

If you are having a problem with the traction control system, it can prevent going above idle.

Not on a 92 300e. All mechanical throttle linkage via cable, and rods with ball and socket type joints.

Maybe the microswitch on the throttle linkage? They can cause problems but I dont know about anything that severe...
But overall I'd have to agree about something being broken on the throttle linkage and internittently not engaging or getting stuck.
I assume this is the m103?

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Streetside: 1987 Mercedes 300E Petrol Blue/Green
2014 Ford Mustang Grabber Blue
1999 Ford Ranger Green

Dockside: 1968 Eltro 17
1985 Silverton 34C

The system I'm speaking of is a hybrid where the throttle body has a electric motor and clutch plus an actual mechanical linkage. The electric motor can override the linkage.

Have a look here for a 94 E230 http://www.w124performance.com/docs/mb/M104/M104_ETA_rewiring.pdf

I know at least the M104 ASR cars had this, I have a 1991 300SL with such a system and a motor from a 96 E320 that still has this type of arrangement

97 was the first year for true drive by wire ( no linkage between the pedal and throttle blade ) at least on the SL320 , C280 , E320 .

Have a look here for a 94 E230 http://www.w124performance.com/docs/mb/M104/M104_ETA_rewiring.pdf

Right, I'm familiar with how those engines are set up, but the OP's car is a '92 300E, which came standard with the m103 engine, which utilizes a straight mechanical throttle linkage to actuate the throttle plate.
Your 1991 SL has the more advanced 104 engine, but the 300e ran with the older 103 engine until 1993 as the standard 3.0 option.

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Streetside: 1987 Mercedes 300E Petrol Blue/Green
2014 Ford Mustang Grabber Blue
1999 Ford Ranger Green

Dockside: 1968 Eltro 17
1985 Silverton 34C

Check ignition coil first , should have a spark blue in color able to jump a1/4 to 1/2 gap, next item, eha can cause that, test and or replace, last check fuel pumps and or relay, disconnect fuel line under hood into a container should flow 1 litre in 20 seconds

I'm not certain about this but I thought that, in the USA, 300E got the M104.980 engine in about 1991. Or was it just the 300CE?

Maybe the OP could confirm either 1 or 2 camshafts?

Either way the rules for the M103 and the M104.980/1 are much the same with cable only throttle linkage.

RayH

Is it fitted to an automatic transmission?

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On the whole I'm surprised it isn't stalling - the throttle valve (below the air flow plate on the mixing unit) should make enough suction to drag the plate down...

...perhaps a simple with engine off check - push down on the air flow plate (just under the air filter) will show some stiff movement?

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I thought the first load of M104s also had CIS though...

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

rayhennig, a 1991 300CE has the 104.980 engine with CIS. A 1993 300E 3.2 has the 104.992 engine with HFM, as do the 1994 & 1995 E320 models. The 1996 & 1997 E320 models have the 104.995 engine with HFM.

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Fred Hoelzle

Yes, I've heard that but I'm in Europe and things were different here. However, the OP said his is a '92 car. Maybe he should take a photo and reveal all to us, then we'll know.

And yes, to the other reply, the early M104s - 104.980 & 104.981 - had the Bosch KE Jetronic with separate ignition controlled by the hated, €3000 EZL.

RayH

rayhennig, tell me about the expensive EZL (ECU). Our daughter had a 1991 300CE which suddenly died on the highway. Since I also had a 1991 300CE I loaned her the EZL so she could drive her car. After searching for months for a new EZL the Parts Department manager at our local MB dealer realized an EZL for a 1991 300SL was identical and ordered one. As I recall it cost $2,500 with a discount.

The secret to extending the life of the EZL is to maintain the ignition system by-the-book.

__________________
Fred Hoelzle

The car is an Auto trans M 103 engine.

I believe these are in the clear as far as biohazard wiring harness issues. .

I checked the linkage and found the cruise was actuating when the accel./linkage was pressed. Like it was working against the mechanical linkage- Mind you this was with the cruise off! I was thinking about the traction control if this isn't the answer as I will disconnect the cruise actuator linkage.

Supposedly the car has a misfire .....but I never felt it .

__________________
92 300e 205 k miles decent -wife's ride
91 300 TE many upgrades and very clean-Junk yard rescue ( son's "hot rod")
68 250 s Low rust great shape
91 300e 236k ( rear ended and sheared metal subframe mounts /sway bar )
85 300TD 310k

Below have moved on
77 300d 36k miles one elderly owner! Now in Ca fully restored
79 300 sd 49k miles( time capsule clean )sold and still in ohio
66 230s new at factory "das boot" gone.
93 190e 2.6 crunched-hard no injuries
69 220d rusted away

A small detail, the 97 E320 ( plus SL320 / C class ) had ME2.0 / 2.1 and the 5 speed electronic shift 722.6 trans. I have each of the 97 cars mentioned and pulled the engine from a 96 E320 HFM / 4 speed hydraulic shift trans.