Owner for just 30 minutes and this!!
 

I just purchased a '96 C220 from a bank (repo). Incredible showroom condition, only 74K miles and beneath the NADA book value. Couldn't pass it up. Well, I took delivery of it on Sunday, started the engine up (ran soooo smooth), checked all the lights, gauges, etc. then drove it 1 block to the gas station. I filled it up with regular unleaded and then drove it to the air/water station not 100 feet away.....and there it died!
It cranked very smoothly, and sometimes almost seemed like it wanted to "fire" but never did. I called the MB 24-hour hotline and the tech there ran me through some checks. I made sure the gas cap was secure, the starter shutoff relay was operational (green light on below the rear view mirror), and tried it in Neutral. Still cranked fine, but simply didn't start up.
After an hour of this, I had to get it towed to a repair shop.....so now the repair garage has had it longer than I've owned it... Still not flipping my lid since I know that MB's are very dependable cars.
Does anyone have any idea what could be the problem so the repair shop doesn't try to snowball me and my pocketbook? Actually, the bank said they would help with the repair & towing cost.

I don't think it is the source of your problem, but I believe your engine requires Premium Unleaded gasoline, not regular unleaded.

Are you sure it was gas and not diesel or kerosene?
 

Hey, it has happened before.
On the other hand, old gasoline in the tank. Junk in the gas tank that move to the fuel filter with the new gas?:confused:

Unleaded instead of premium gas
 

This does bring up a good question...the owner's manual states to use the premium unleaded to keep from damaging the catalytic converter. Is this an accurate statement, or has others used lower grade gas without problem? How about a mid grade gas and octane booster?

Do a search!
 

Fo gasoline grade and questions of that nature.
Good luck!

Re: Unleaded instead of premium gas
 

By the time you buy mid grade & octane booster, you can buy premium grade & save money.
P.S. If the manual says premium, it means it. ;)

The major costs of owning a car are the cost of money and the cost of depreciation. The cost of fuel is not all that significant. Believe me, you should use premium and avoid the so-called supermarket stations like Costco because they use high sulfer content fuel from South America (that's why it's cheaper).

Stick with premium from name brand outlets that have a high turnover.

Hi Randy L

Sorry to hear about your misfortune.

I would not mind betting that when you filled up (with whatever) it was actually water (or a significant %), there will have been enough fuel in the lines to get you to the air/water station and thats it. While within the tank you now had a layer of water to feed into the engine -it don't burn that well.

Because of the knock sensors in all MB gas engines since the mid eighties, regular will not DAMAGE the engine, but it is false economy.

Once the knock sensor detects knock the system will automatically retard ignition timing reducing power and efficiency.

Put Premium in it.

Good luck,

Sounds like the fuel pump relay went south. (202s do this as do 208's. )



Joe

Thanks for all the inputs! After I put the regular unleaded in it, I realized what I did and (since I was stuck at the gas station) got a can of octane booster (104+) for the gas. Premium unleaded it will be from now on. I'll keep you all posted on what was found. It will be looked at today.

premium or regular
 

A lot of us here simply use regular unleaded and it has no significant effect on the engine's power or idle running. I think the regular is 92 here and the premium is only 94. Some stations do offer a higher octane to 96 or 98 I am not so sure. For Benz engines they reccomend at least 92 which means regular is ok, but 94 or higher will be even better. But is premium really necessary? I am referring to the family cars and not the AMG or SLK and CLK varieties.

It is important NOT to base your octane needs on what folks in the USA use - octane ratings differ by nationality. What is called 92 octane in the US used to be a higher number, but the basis for the ratings was changed awhile back. Find out what octane rating MB requests you use in your locale.

Steve

The octane rating of "Premium Unleaded" differs across the U.S., too.

In Southern California, premium unleaded is 91 octane. Many parts of the country get 93 or 94.

Found out the problem!!!!
 

The repairman when he was troubleshooting noticed the fuel pump wasn't even operating. He isolated the problem to a faulty fuel pump relay. I should be on the road tomorrow!!!
Thanks all for the prompt replies and suggestions. While it wasn't water in the gas, etc., these are still VERY viable causes and are items anyone should check for similar problems.
In fact, I once while I was in Germany, I had BMV 528iM that got water and air in the fuel injection line. Cranked but never started...cost me $200 (1995) to have the entire fuel injection system purged and reprimed.

Randy

A QUESTION?

when you fill up again after you have run regular with premium .. how does the computer detect this and advance the system??

Looks like Joe was right.

Pretty simple. The computer advances ignition timing until it " hears " knock.
Then it retards the timing in small increments until knock is gone.
I.e., you cheap out on octane rating, you will end up with less timing advance & slightly less torque/hp/snap, balls, whatever you want to call it.
The difference would be hard to notice for some people. ;)

M103s don't have knock sensors, and will rattle, ditto for M117/M119 early with K-jet.

Play it safe, use premium. Detonation at high speed, when you cannot hear it, will roast the piston crowns and valves, not cheap.

Peter

Right on psfred! I once purchased an off-lease vehicle that required premium unleaded, and shortly after owning it the check engine light came on. The car ran fine, but I brought it to the dealer to have it checked out and they discovered that one valve was dead and the others looked pretty lousy. The tech offered that the previous owner didn't use premium. Thankfully the work was covered under warranty, otherwise it would have been a $2,000 lesson on why you should pay the extra pennies at the pump. Of course, the lessee didn't care.

I know this is heading off-topic, but if the
M103 has no knock sensor, what effect is there to removing the
'retard resistor'?
Will it advance the timing beyond safe levels or just a little bit?
Thanks, Bob

The ignition timing/mixture program for the M103 is fairly complex, but I've heard that the resistor is there for certain modes, I think low speed low rpm high load or some such. removing it may cause knock (and may also get you some small amount of power at certain rpm).

I'd leave it alone, MB ain't gonna cheat you out of performance just to make the car slower (drive a C280 for proof).

Peter

Yeah, I haven't been too tempted to unplug it. It's pretty well plastic-tied to a hose in an inacessible location, probably to preclude the casual tinkerer, like me. :)
Also I do notice a difference in throttle response with different fuel brands; my 300TE seems to be favoring Texaco premium, at least in this part of eastern Pennsylvania.
Now I need to remember to carry Techron and/or the Progard Fuel System Cleaner with me when I might be refueling.

One of the not so obvious benefits of using premium grade fuel is, that it contains a lot more detergent than cheapy gas. ;)

thanks manny.;)

HFM fuel injection systems, like that on the 1993 and later M104 engines, are designed so that idle speed can't be adjusted. Idle speed is completely controlled electronically. This HFM injection system also has adaptive technology that compensates for conditions such as engine wear and unmeasured intake air and is designed to maintain driveability as the engine ages.

HFM-SFI can retard engine knocking to just the knocking cylinders, unlike EZL technology, which retards spark timing across the entire engine. This keeps the ignition timing point as advanced as possible for maximum power output.