[Benz4Chance]

Hi everyone! New to the forum, new Mercedes owner

I recently acquired a 1997 e320 with 144,000 miles from the original owner. Right before I was going to buy the car, I was told that the check engine light came on and the owner had it diagnosed. He came to the conclusion that the error code meant it needed a new crank position sensor (he is a "recreational" mechanic and a big diy'er). Wanting to remedy the problem before selling the car to me, he bought and replaced the cps; bingo, problem solved, no more check engine light. During this time I did my research on w210s and Mercedes Benz in general, fearing I might be making the wrong decision in making this baby mine. After reading as many reviews as I could, searching this site for possible future problems and researching the reliability of Mercedes in general I came to the conclusion that I...rrrreally wanted this car; I'm a girl, but I can change my own oil, replace filters, an alternator, diagnose problems pretty well. I've got some skills when it comes to mechanics; I'm not afraid to get a little dirty.

Anywayzzzz. Here's the problem:
When the check engine light originally came on, the previous owner mentioned THAT'S exactly when the car started having issues starting. It will start, every time, eventually. It won't ever NOT start. But! Sometimes, RANDOMLY, it takes up to 4 or 5 seconds to turn over; it cranks and cranks (STRONG) but sounds like it's not getting enough gas. If I turn the key off and immediately try to start it again, BLAM, half a second and it's purring like a kitten. So I RESEARCHED. Fuel pressure regulator, right?? I read a couple threads suggesting turning the key to the ON position and waiting a few seconds to let the pressure build in the lines to determine if it was a fuel delivery problem...and this seemed to work...SOMETIMES. Or maybe it never really made a difference and the fuel delivery problem remained sporatic :-/

I've replaced the fuel pressure regulator and it's STILL struggling to start. But the thing is, the car runs perfect otherwise. No sputters, no stalling. It sounds amazing once it's running. If it were a spark (plug) issue, wouldn't it run rough? If it were a fuel injector issue would it still be as smooth as it is? I'm STUMPED. And there's no check engine light; it hasn't been on since the replacement of the cps.

I love this car and have no problem working on it...I just don't like throwing parts at a problem

Anyone have an idea to solve my problemo? I feel like I might have to replace the damn starter soon, with how hard it has to work sometimes :-/

 

[Musikmann]

Have you tried to read the codes? That's where I would begin. There is an interpretation list in the stickys or you can always post them in your thread and someone will help. Welcome to the forum!

 

[Benz4Chance]

That list is awesome; if the check engine light ever comes on I'll make sure to get to a HF code reader so I can utilize it.

But my check engine light isn't on. I don't have a code to research...

 

[Mercedes mechanic]

I would guess that there is a problem with the tank. Try cold starting it with the gas cap off. See what that does.

 

[fabbrisd1]

I might suggest you try the "search freature" for the forum and you will find helpful posts like this one below:

http://www.benzworld.org/forums/w210-e-class/1591161-97-w210-hard-start.html

If you put in a new Bosch fuel regulator that's like $55 so far.

If it was me I would make sure to replace the fuel and air filter with fresh Mann (total like $30) and buy a bottle of Stabil Blue (Marine Forula) and dose a tank per the instructions on the bottle (the bottle will be like $12 for 2 doses) it's a real good agressive but not too solvent fuel system and injection cleaner. So now you're at like $45 more in parts.

I would let the cleanup run it's couse and while you are waiting search the forum for tips on fuel pump diagnosis (the Pierburg is pricey, but the China knockoff's are horrible) and how to test at the front fuel rail and how to go thru the injectors.

I would pull a spark plug and check the condition, your's should only use the original style copper plugs and they get real cranky after about 30K miles or so.. platinum and upgrades don't really work well in your engine. Plugs are like $2.50 each..

I understand this happends to you engine "cold" and engine "warm" with the sdame frequency, right ? If this happends more or longer with warm engine - then hope the prior owner (unbeknowest to him) used a non-Hella CPS - because those Auto Zone/NAPA, etc non-Hella CPS's often only last 2-3 weeks because they are simply a bad knockoff of the Hella. If I recall correctly '97 was a "split" year on CPS, meaning their are two parts for that year, and your VIN at the dealer will idenify which CPS is the right one for your car.

Keep the faith !

 

[Check Codes]

Welcome. You've gotten some good information here already, so I just have a couple of thoughts.

One, the lack of a CEL does not equate to a lack of codes. The algorithm will allow some codes to store as pending even when the CEL doesn't come on. So I'd still say check for codes. In Phoenix you can cruise by Autozone and they will read them for free. I would recommend you get one, because for a DIYer it's an essential arrow for your quiver. But that way you can have them checked free while you wait for the $30 one from Amazon to arrive. (It's the same as the HF one, just cheaper.)

Is your fuel pump noisy? If so that's often a sign it's ready for replacement, and when it's at that stage it can exhibit this symptom. Similarly, if you can correlate the long crank condition with less fuel in the tank, that's often another indication of a failing fuel pump. Finally, I didn't see a mention that you'd replaced the fuel filter, which Fab mentioned, so consider this a "plus one" on that, too.

Hope those help. Good luck.

 

[Benz4Chance]

Mercedes Mechanic- I tried cold starting with the gas cap off and I got the same result: 3-4 seconds to start.

fabbrisd1- Yes, the fuel pressure regulator was Bosch; I've owned VWs and I remember when Bosch was an "upgrade". The car sat for a long time before it came into my possession and the fuel pump had been replaced because of that (he bought it from Mercedes; I remember him telling me it was something like $300), along with a few filters he went through (apparently the fuel tank was 3/4 full when it was not being driven and it was an endeavor to drain the bad fuel). I know I should have mentioned this in my initial thread but I was trying to be as thorough as possible explaining about the work I myself had done on the car. I've put premium gas in it since I've had it and the previous owner told me he had never put anything less than 91 octane as well. I've opened the airbox and looked at the air filter; it's new, clean. I will replace the fuel filter again and have Autozone run a diagnostic while I'm there. The previous owner didn't mention anything about plugs so I will take a look-see at them tomorrow as well. I've also researched a little on cps units; I was a little worried from the beginning that it might not have been the correct replacement (if you want something done right, ya gotta do it yourself, right?!). I have the receipt from where he bought it...and the cps he took off the car as well. How crappy would that be, if he spent money on a part that isn't even correct? Ugh. The fuel pressure regulator WAS $53...but the one on the car was the original as far as I could tell and I'm justifying the money spent by telling myself it was OLD, and would probably need to be replaced sooner or later anyway

gregs210- It doesn't matter how much fuel is in the tank.

It just seems so weird to me that it struggles to start, only on the first crank...but if I turn the key off and try again, it starts up in a flash. If it were a fuel filter problem, wouldn't it struggle to start on the second crank as well??

You guys have given me so much good info...
Thank you thank you THANK YOU.
I will post again once I've started getting some of this stuff done

 

[oneforall]

I am late to the party, have you tried to clean the tip of the electronic keys? the amber color part, i have a theory on this, my wife's new key start the car every time, while my old one have hard starts sometimes(like one in 10 starts). so i cleaned my old key( the amber part) with camera lens cleaning paper and camera lens cleaning fluid. the long hard crank goes away, then a month or two later, when my key gets dirty again( i put the key in my pocket a lot), i have this problem come back, so i clean the key again. The problem go away again. Anyhow, it is cheap fix and may or may not work for you, but may worth a try.

 

[Benz4Chance]

I went to Autozone today, suffered through the guy flirting with me and asking me for a ride in my car...

"NO CODES", ugh. He wanted to "check the charging system" also but his device was "on the fritz". I don't THINK it has anything to do with the battery or alternator, but...I would have let him check it out if his equipment would have been working. I'd read that the battery is under the rear seat but I still had to consult my owner's manual to find where the latch/tabs were that unlatched the bottom of the seat

I cleaned the laser window (amber) part of my electronic key too...no dice. It seems like it's getting worse now; taking longer to start

But the car drives like a dream, oh how I love it. Young kids wanna cut me off or tailgate me in their Lancers and Civics...but my acceleration doesn't allow for much beat-down.

To do tomorrow: check plugs and injectors. Thanks everyone, again!!

 

[Musikmann]

...It just seems so weird to me that it struggles to start, only on the first crank...but if I turn the key off and try again, it starts up in a flash. If it were a fuel filter problem, wouldn't it struggle to start on the second crank as well??...

.

A weak fuel pump and/or dirty fuel filter could still explain that. The pump could be working well enough to push some fuel but not quite enough, and/or the filter is partially clogged so you're getting the same net effect.

I'm with you that the charging system has nothing to do with this. That was just a ploy so the guy could flirt with you a bit longer!

To access the battery, there are 2 releases on both sides of the rear seat. Hard to see (they are low) but they are there.

Please post a follow-up concerning the plugs and injectors.

 

[Check Codes]

It just seems so weird to me that it struggles to start, only on the first crank...but if I turn the key off and try again, it starts up in a flash. If it were a fuel filter problem, wouldn't it struggle to start on the second crank as well??

My apologies, I missed that detail the first time 'round. Something in my brain is whispering, "check the K40 relay...check the K40 relay" and if your soldering skills are up to snuff you can redo all the lugs. If you do a search using the google custom search ("K40" is too short for the native search function) you'll find some threads on it.

Good luck and keep us posted!

 

[Benz4Chance]

I'll post as soon as I get a chance to pop the hood at NIGHT; it's 112 degrees during the day and I'm 8 months pregnant. SUCKS in the sunlight!

I was thinking about ordering a fuel filter anyway. Replacing it couldn't HURT, right? I'm gonna get a Mann filter. They're superior, correct? Maybe the previous owner didn't pre-soak it and the (fibers?) are damaged...? I've read how you're supposed to pre-soak it to prevent internal structure failure or something...?

And YEAH, those lil' releases on the rear seat are INCOGNITO, forrrr SURE.

THANK YOU Musikmann

 

[Benz4Chance]

gregs210- I'm actually getting my hands on a soldering gun here pretty quick; I need to "fix" my power seat adjusters and as soon as I find the MOTIVATION to tear off the door panels I'll be able to adjust the passenger side without having to use one of the PRESETS

Phoenix is wonderful in November. And I DO already know you drive a nice car...

 

[Musikmann]

...I was thinking about ordering a fuel filter anyway. Replacing it couldn't HURT, right? I'm gonna get a Mann filter. They're superior, correct?...

The autohaus site is unclear on that. They list both a Mann as OEM and a "genuine" MB filter. I don't know how to interpret that. I think I would call them for clarification.

You're very welcome and congratulations on your upcoming child!

 

[quicker240]

slow start...

The link he gave you in the second post was the one I started. Your symptoms are identical to mine. Even the exact same model car and mileage. The reason for the long crank the first time and not the second, is that the fuel pressure has slowly bled off through the leaking injector, it takes a few seconds to build back up. When you quickly restart, the pressure is still up where it should be. It sure seems like the same problem by your description.
The good news is that the way to check it out is free and pretty darn easy. Just pull the fuel rail bolts, lift the rail, injectors and all and lay it on top of the engine, turn the key on (do not engage starter!), and look for a dripping injector. Hope this helps.:thumbsup:

 

[Benz4Chance]

Okay, so!
Sorry it's been so long guys. I gave birth last week and things have been...busy, to say the least

I replaced the spark plugs and checked the injectors (which are fine). I now have a fuel filter sitting in the garage I want to install. I've seen a few tutorials which all involve putting the car on a lift. Is that going to be the only feasible way to get this done? Ooh! Since I haven't driven it in awhile, I've NOTICED...when it sits for a day or more, it starts PERFECTLY, no struggle. I'm hoping that supports my theory of a clogged fuel filter...

 

[Kobus]

Okay, so!
Sorry it's been so long guys. I gave birth last week and things have been...busy, to say the least

I replaced the spark plugs and checked the injectors (which are fine). I now have a fuel filter sitting in the garage I want to install. I've seen a few tutorials which all involve putting the car on a lift. Is that going to be the only feasible way to get this done?

No lift required. Since you are now thin again you should be able to slide underneath the car. Or to make it easier, you can lift the car on one side. Of course, now you have to extra sure that the car is well supported.

 

[keyhole]

I now have a fuel filter sitting in the garage I want to install. I've seen a few tutorials which all involve putting the car on a lift. Is that going to be the only feasible way to get this done?

B4C - changing the Fuel Pump.

The reason for getting the car on a lift is that working under a jacked-up car means laying on your back, and maybe getting fuel in your face.

The job is do-able though. You should get some clamps to close off the fuel lines (it can be done using an adjustable wrench - we call them mole-grips in the UK). You don't want to damage the lines by closing them too tightly.

As you can see from the WIS drawing, you have to torque the banjo bolt to 25 Nm, and insulate the pump with the sleeve.

The WIS advises the pump replacement (assuming you have engine 112.941) is Pierburg E3L.

Hope you are both doing well! :thumbsup:

 

[Check Codes]

B4C - changing the Fuel Pump.

The reason for getting the car on a lift is that working under a jacked-up car means laying on your back, and maybe getting fuel in your face.

The job is do-able though. You should get some clamps to close off the fuel lines (it can be done using an adjustable wrench - we call them mole-grips in the UK). You don't want to damage the lines by closing them too tightly.

As you can see from the WIS drawing, you have to torque the banjo bolt to 25 Nm, and insulate the pump with the sleeve.

The WIS advises the pump replacement (assuming you have engine 112.941) is Pierburg E3L.

Hope you are both doing well! :thumbsup:

CONGRATULATIONS on the new arrival. Just remember that sleep is highly overrated, and you'll do fine. (On a personal note, my Thanksgiving trip got cancelled as I'm in a show...maybe January?)

Key: filter, not pump...no banjo bolt issue, just the funky spring clamps on the hoses.

Because of the weight distribution, you can use the lift point behind the driver side front wheel (quality floor jack) and it will ultimately raise the whole side, then you can stick a jack stand under the lift point in front of the rear wheel and let the jack down enough to engage it.

There is a DIY on the job in the stickies. Definitely clamp the hoses, and either drop the cash on the costly-but-cool Hazet pliers or cut off the spring clamps (dikes work fine for this, linesman's are too bulky) and just buy new gear-type clamps.

Good luck, and if you've a mind to, please post a small pic of the wee one. If a girl, I trust you named her, "Mercedes?"

 

[Check Codes]

ddillo just reminded me of another possibility.

Since the long crank symptom arose after the CPS replacement, it's possible the work disturbed some of the old insulation on those wires, so unclip it and carefully inspect the wires.

Also, I seem to recall the possibility of small oil leaks on the M104 that can wet the connector for the cam position sensor, so you may want to carefully inspect that.

Take care and enjoy the ride,
Greg