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Free HP? timing retard resistor in US models?

2208 Views 1 Reply 2 Participants Last post by  MTI
I found this info on the net and was wondering if anyone has tried or heard of this?
Where can I find this resistor in my 1991 190E 2.3?

Free HP!

Yes, its true, for all the W201 and W124 owners, here is a simple modification that will yield you better throttle response and more power. While researching some other options for upgrading the ignition, I came across some interesting data on the MB service CD. On the Euro spec MB's ignition, there is a item called a reference resistor or R16/1, it is a manually adjustable dial that allows you to retard your ignition timing. On our US spec cars we don't get this wonderful option, but we do have a fixed ohm resister to set out ignition timing. It is a 750 ohm resister which gives us a 6 degree retard in timing. This is standard on all US spec W201's and W124's, its MB answer to the poor, low octane gasoline we have in the US. Now if you are like me and only run high octane 92+ in your car, you can pretty much eliminate the 6 degree of retard altogether. My removing the R16/1 resistor, you in effect end up with no retard. This may be borderline for 92 octane gas so another option (if you end up experiencing pinging) is to order from MB a R16/1 resistor in 2.4 kohm. This will give you 2 degrees of retard.

So far with no R16/1 resister and 92 octane gas, my 190 is running great with no pinging. The improvement is very noticeable (my seat of the pants meter). Anyway, if you want to try this on your car I can save you a bit of a headache and tell you where the R16/1 resister is located. On my 1992 190E 2.6, it was located by the battery behind the black plastic panel (which is directly behind the battery and hides your ECU and OVP). You should be able to spot it rather easy since it is wrapped in black electrical tape. Once you locate it, just unwrap it and remove the R16/1 resistor, its a small black plastic plug like item with two contacts sticking out of it. Once removed, you should tape up the wire harness and hide it back behind the black panel. Fill your car up with 92+ octane and enjoy. If you experience pinging or any other strange behavior, you should put the resistor back and see if MB can order you the 2.4 kohm R16/1. Also, on the 16 valve 190Es, the R16/1 is connected to a wire harness coming from the firewall toward the #3 and #4 intake manifold runners, it should be dangling out from the harness and its also wrapped in black electrical tape. Below is the complete chart of values (taken from the 1986 16 valve service manual.

No resistor = no retard
2.4Kohm resistor = 2 degree retard
1.3Kohm resistor = 4 degree retard
750 ohm resistor = 6 degree retard (standard in my US car)
470 ohm resistor = 8 degree retard
220 ohm resistor = 10 degree retard
0 ohm resistor = 12 degree retard

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'85 2.3-16 '99 C280 '11 GLK350
4,803 Posts
If you have'nt been to, you should go to read Rik's pages on very high qu...

If you have'nt been to, you should go to read Rik's pages on very high quality mods for the W201.

About the R/16 . . . it does change the timing, but results have not been consistently good. While some report a "boost" others have had engine problems and replaced the resistor. The resistor does not exist on the W201s made prior to 1987, so don't bother looking if you have an earlier model. On the euro 16 valve engines, MB used a variable resistor with a dial switch to choose different degrees of retard.
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