Mercedes-Benz Forum banner

1993 300SE has new wiring harness

2K views 6 replies 4 participants last post by  sammywater 
#1 ·
Bought this car with a wiring harness on the engine that was absolutely spaghetti, replaced that and the engine starts now and will run smoothly only if you give it enough gas, keep it about 1000-1500 RPMs, if you let it idle it will die and not restart. I'm thinking crank position sensor? Do these cars have a mass airflow meter that can be cleaned? My 1996 C220 acted weird and erratic and I cleaned its MAF sensor and it cleared right up. This car is SO close to being back on the road and purring! Any ideas will be greatly appreciated.
 
#2 ·
I know many here will tell you otherwise, but if you buy the correct cleaner, you can use it to clean the sensor in the housing. I have done this and no problems, Just make sure to use common sense and let the agent clean the part instead of the pressure from the jet cleaning the part. In other words, put some distance between the nozzel (jet) of the can and the sensor and you should be fine. But I think its your crank sensor. Actually, I take that back as this is a 93 and I don't know how the electronics regulate idle. I will say to check you dist caps for moisture, vac, etc.
 
#3 ·
If your upper harness was junk...you should probably know that the same eco junk wiring is used in your ETA and its harness and the lower harness. Have you changed the OVP relay? Checked the build date tag on the ETA? If its older than 1998, there's no dodging replacement.

Good luck
 
#4 ·
Sammy

You can test the crank position sensor with a volt meter set to Ohms. Pull the CPS cable from your EZL module and test there. You need approx 820 ohms of resistance. In most instances, CPS sensors are pass/fail and nothing in between. Check all the blade fuses in your base module as well.

Jayare
 
#6 · (Edited)
Thank you, this gives me something to go on. Do you know a part number for the lower harness? Mine is a 1993 300SE made in late 1992. Is there a replacement for the ETA or can it be remade at home? Maybe there is a DIY about it..the link to the DIY just leads to a page full of ads? Thank you to my friends at Benzworld!
 
#7 ·
Well, looking at the cap it is certainly Total Junk, and completely worn out. A cap that is worn like this can cause a ton of problems, so I am immediately ordering a new cap and rotor, Hopefully that may be all that's needed to make the engine happy for the short term; I will still be addressing the other needs mentioned above. Once that is installed, I will report back here. Thanks to all of you again..
 

Attachments

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top