I have a 94 e420 with about 90000 miles. Have developed a stall at idle. Also got a check engine light. Local mechanic says a code 6 for idle modlule. He says the part is about $900 plus labor. I have seen other posts that indicate a dirty throttle body can cause a stall, could it also cause light? How can I clean the throttle body? Does it require removal and disassembly? Can I do it. Have moderate mechanical experience. Any help?

99% of the time, it is the throttle body. I have replaced several and fixed all of the complaints.

__________________
Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

as a good newbie, i did a search and it brought me to this thread (and a couple others). my girlfriend's cousin is flat out sick of her 1994 E420 because it just stalls at random. she even GAVE it to her kids (30 somethings) and they don't want it.

so, from what i gather, i should first clean the throttle body. worst case is that i need a new throttle body. the car only has 29,000 miles on it. in a post, it says that the computer was not properly calibrated from the factory. does this cause the car to stall or just run rich? i hear chip talk going on here. this seems like a far cheaper idea than a reflashed ecu. or can i give my ecu as a core and get a "corrected" ecu pretty cheap?

wouldn't a rich running car eat O2 sensors and converters like no tomorrow?

can i get an aftermarket maf that could be calibrated to adjust the rich condition? we ford guys have pro flow, i even have on on my SHO.

i am learning that all cars are fairly similar. being this mercedes E420 and my SHO are both pre-0B2 (pre 1996), we have a lot in common. on my SHO, erratic idle can be caused mainly by the idle air bypass valve. it's a mechanical spring loaded sensor that continuously adjusts idle for smooth operation. problem is that as it gets old, the spring gets out of whack which results in erratic idle and stalls. i know my gf's 1997 audi A4 has an IAB, does this mercedes?

does this stalling problem result in erratic idle (jostling 250 rpm or so until stall) or does the car just flat out stall. if the car dies out of nowhere, can it be the cam position sensor or the crankshaft position sensor?

i am very eager to hear your responses. i sure hope i can nab this car as my SHO now has nearly 123,000 miles on the clock. time for a new sled.

see ya,
Robby

__________________
92 Ford Taurus SHO 5 speed
210.5 HP 196.4 LB Torque at the wheels
silver on gray with all options
ss y-pipe with high flow cats
SS UDPs
PRO M 80mm MAF
Walbro 190lph fuel pump
Tokico struts
Eibach springs
sho shop motor mounts
edelbrock RPM
shonut aluminum sub frame bushings
26mm rear sway bar
sho shop sub frame connectors
Yokohama AVS ES100 225/55/ZR16 tires

Tell the kids to give it to me.

The EA's (or throttle slides as MB calls 'em) Will gum up, get twitchy readings from the refernce sensors and such, get a qualified tech who is familar with this system to check it out. The short harness on the EA will also go feet up as will the engine harness in general. There also is a vent hose on the r/h valve cover of the 119 the will go bad causing some weird issues as they collapse. (this hose leads straight to the base of the ea)

94 should run a seperate ECU for CC/ISC/EA called E-GAS.



Joe

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Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.
Raleigh NC
919-881-0364

thanks joe! i had to read your post a couple of times to get my hamster brain to comprehend

in the worst case, i would have to replace the throttlebody, the short harness, vent hose and the separate ecu, correct?

in the best case, i just clean the the EA? will this be a recurring situation every 25k miles or is there a permanent fix? if no fix, then i better learn how to do this procedure myself, eh?

lastly, what's this stuff i hear that the ecu on these cars runs to rich from the factory. is this true? if so, will this have adverse affects on the car? what is the "rich" a/f ratio typically? can i leave it alone, or have a chip burned on a dyno with a wide band O2 hooked up?

i love cars. if/ by some chance/ i get this thing, i'm not one to cheap out. just look at all the money i dumped into my TAURUS

oh yeah, how stout are these trannies? i come from the world of manuals. i know ford automatics are really bad. the fwd autos can die in 65k. the rwd, liekethe mustang, are typically 100k. still not that great.

we shall see. if this car falls through the crack, is the E420 a good car to keep an eye out for? about a year ago, i was looking to buy an MB 560SEC. man, that's a lovely car! i ended up holding off due to i got cold feet about buying a 15 year old mercedes.

see ya,
Robby

__________________
92 Ford Taurus SHO 5 speed
210.5 HP 196.4 LB Torque at the wheels
silver on gray with all options
ss y-pipe with high flow cats
SS UDPs
PRO M 80mm MAF
Walbro 190lph fuel pump
Tokico struts
Eibach springs
sho shop motor mounts
edelbrock RPM
shonut aluminum sub frame bushings
26mm rear sway bar
sho shop sub frame connectors
Yokohama AVS ES100 225/55/ZR16 tires