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96 s320 and 97 e320
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Discussion Starter #1 (Edited)
Thanks in advance for any insight you folks can give me.

I bought this car a few days ago, 120k miles. The guy who sold it to me brought it to me already running. I checked it out with the car still running and then took it for a short test drive. I shut it down, we dickered, and I paid him in cash. About 15 minutes after shut down I was ready to drive it home, but it wouldn't start. Occasionally it would fire but wouldn't stay running. After about another 10 minutes and a total of at least 40 attempts it fired up and I drove it home, 60 miles. It ran fine the whole way, up to 80 mph at times, idled fine at stoplights, no problem.
I worked the next day and tried to start it again in the evening. It cranked but no fire at all. Being it is Palm Springs and we had a 115 degree day and the problem starting after stopping the first evening, of course my first guess was CPS. I didn't want to deal with it, so I put off checking anything until this morning, a balmy 95 when I started.
It cranked with no fire attempt at all. I eventually pulled the intake to access the throttle body and sprayed some starter fluid in. It fired until the starter fluid was gone. Has to be fuel delivery problem, right? I pulled the cover for the fuel pump and filter, it looked like they both had been changed at some point. I separated the filter from the pump and when key was turned to start, the pump gushed out fuel against my fingertip pressure. I removed the filter and as I was draining it I noticed the gas had a dark color to it, Like carbon in the gas. I replaced the filter. A slight change in symptoms now. Prior to changing the filter I had no gas leaking out of the 15mm plug in the fuel rail when I loosened it, although I could see gas there. Now there is a release of gas under slight pressure when I first loosen the nut. Also occasionally the engine will fire for just a moment which it didn't do earlier today at all. I pulled the plugs and replaced them all with bosch super +, same as the ones that came out. Old ones were about .060 gap.
One more clue I found was earlier today I read the pending codes and saw a P0460 which I cleared and it hasn't come back. I added about 1 1/2 gallons of fuel to the tank even though the indicator showed 1/2 tank. The indicator did rise after the fuel addition.
Any clues as to where to proceed from here???
 

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'01-E320 & 02-ST2
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31,631 Posts
If you are not getting good pressure at the fuel rail (I'd recommend using a gauge, fingertip is hard to establish) then you need a fuel pump. While you say that one looks as though it's been replaced, you don't know how long it's been on there, whether it was bought used, whether it's a good brand, etc.

It is also worth pulling and examining the K40 relay to see if any of the solder points look cooked.

And while it's not related to your current symptoms, you haven't put the best plug in the engine. Just basic copper F8DC4 is all you need for the M104. The super + are resistor and can cause their own problems.

Hope that gives you some things to work on. But I do agree with you that it sounds like a fuel supply issue. Until you have it under serious pressure at the rail, you're not going anywhere. ;)

Good luck.
 

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96 s320 and 97 e320
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35 Posts
Discussion Starter #3
After doing some more reading here I figured my thumb pressure wasn't good enough! I just got back from Autozone, where they have tools for loan, with a pressure gauge. Have had it hooked up for about 15 minutes now. It started off at 55 psi while cranking and has settled in at 52 psi.
One of the first things I did yesterday evening was open the K40 relay box and look at it. No visible problems there. I had my roommate start the car while I watched it. I was specifically looking for the fuel relay, and it worked.
On my way back from picking up the spark plugs I remembered the resistor/non-resistor situation from a previous E320 I owned. Looks like I got the resistor ones, crap. Oh well, I wanted to replace them for testing purposes. They should work for that at least.
I just went out to look at the pressure gauge, still at 52 psi.

Am I back to a CPS even though it wants to start with starter fluid????
 

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96 s320 and 97 e320
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Discussion Starter #4
Tomorrow morning I will test some of the injectors to see if they are getting a signal. That seems to be the only thing left other than the cps not sending the right kind of signal to fire the plugs at the right time. I do remember that with the starter fluid there was quite a knock when it did start. Maybe the firing timing is off????
 

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96 s320 and 97 e320
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35 Posts
Discussion Starter #5
Checked fuel injectors voltage

So I put in a new battery because I was getting low. Put the old one in another car to charge. I'm checking the voltage on the disconnected fuel injector connectors with key in position 2. One side to ground reads +12.1 volts, the other side to ground reads +6.4 volts. On all of them. I checked my S320 with the same conditions and the low side to ground is 0 volts. Any ideas????
 

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96 s320 and 97 e320
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Discussion Starter #6
Found this on the internet a few minutes ago. Definitely my problem. Now I need to know how to fix it. Didn't know I had this DAS system, now I do.

On vehicles starting model year 1996 (HHT Diagnosis Version 46), the
RCL system is enhanced with a so-called drive authorization system,
stage 2 (DAS).
The activation of the drive authorization system (DAS) is initiated by
the RCL control module and transmitted to the engine control module
via the CAN data bus.
After activation of the drive authorization system (DAS), the fuel
injection system is rendered inoperative by the engine control module.
The drive authorization system (DAS) can be activated or deactivated
with the infrared remote control transmitter or the master key.
The engine control module and RCL control module are permanently
locked with one another by an identification code. This identification
code can not be erased (see HHT actual values “DAS“ menu
selection 3/6).
 

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96 s320 and 97 e320
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Discussion Starter #7
Up and running today, well kinda!!! Because of my ignorance of the DAS on this model year, I caused all my own problems. But I learned a LOT along the way.
To recap, I bought this car and had problems starting it to drive it home. Here's why. The FOB I was given had the mechanical key falling out of it. I was trying to start the car with only the key and a pair of needle nose pliers to turn it. Since the chip was in the FOB, it wouldn't start until I used the FOB with it. I did eventually stop using the pliers and put the key back in the FOB, not knowing I had to. Just a fluke. That got me home.
The next evening, before trying to start the car I had opened the key to see if I could figure out if the remote was fixable (didn't work when I got it). When I opened it the circuit board and 2 black plastic pieces flew out. I had opened other FOBs but had never seen these plastic pieces. I put one back in thinking it supported the circuit board and set the other one aside.
Today I fixed the remote, finding the push button had been broken off in 2 of the 4 solder points. I assumed the ID chip was on the circuit board so I was surprised that the car still wouldn't start, even though I could remotely lock/unlock now. Eventually I looked for that other plastic piece. When I found it I saw white lettering stamped on it and said to myself "Holy s**t, that's my ID chip". Opened the remote, took out the other plastic piece, and determined this chip slid in up under the red led cover and the plastic piece was meant to hold it there...
Went out and fired up the car immediately!!!!
Had CEL almost immediately and it turned out I lost one of my coil packs (misfire cylinder 2 and 5 and random misfires). I had changed the plugs to a resistor type and immediately paid the price. Several old timers here had told me about my incorrect choice of plugs earlier and I remembered this is one of the symptoms of that. Got a new coil pack and 6 bosch F8DC4s on order for pickup tomorrow.
Thanks for the help guys. I appreciate the knowledge here. I was ignorant and now I'm a little smarter. That's why I come here for help.
 

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2001 Mercedes Benz ML430 w163,2008 Mercedes Benz CLS550, RIP Mercedes Benz 1996 e320 w210
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Congrats man!

I am glad you have found your answer!

By the way, how did you open those fobs?


Sent from my Autoguide iPhone app
 

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96 s320 and 97 e320
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35 Posts
Discussion Starter #9
I carefully pried the pieces loose after removing the battery cover. There is a slot all the way around one half of the fob that the other half fits in to tightly. This last one had already been opened because it got stepped on or something so it was easy.
 

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2001 Mercedes Benz ML430 w163,2008 Mercedes Benz CLS550, RIP Mercedes Benz 1996 e320 w210
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520 Posts
Oh alright thanks a lot man.

Enjoy the ride!


Sent from my Autoguide iPhone app
 
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