1992 190E
About 80000 miles.
All stock.

A friend has a 1992 190E sedan that has not ran for more than 3 years and a week ago I rescucitated the car for her. I did empty out old stale gas and put fresh new one in the fuel tank.

Every time I start the car for the first time in 2 or 3 hours, it starts right away and idles by itself for twenty minutes or so before dying. Once it dies, it becomes very difficult to start again. When I get it started by cranking it for more than a minute, it won't hold idle below 1500rpm and I have to open the throttle to idle the motor above 2k rpm.

Is this Idle Control Valve issue or fuel pump dying?

Thanks for your help, guys.

 

No one knows?

 

i would pull the cis fuel system (located under the air intake box) and give it a good cleaning (be sure to read up on everything before you start. http://www.startekinfo.com/StarTek/o...tedDocId=11832 <-- look in there for the steps involved and what seals will need to be replaced when opening things up) also check the ignition system when it dies. see if it is putting out a spark at the plug. that will tell you if its fuel system related or electrical. and dear god do not crank it for a minute solid! that will burn the starter motor up! best of luck and I will try to answer any questions you have. =]

 

Thank you so much! I will try cleaning the CIS and ICV first.

 

Figure it all out?

 

Hello cyrusyn!

I hope you making progress on this 190E!

I have a question, does the fuel pump turn on when you turn the key to the start position? If the pump doesn't come on, the relay to the pump is more than likely bad. This relay is the MAS near the battery and can be discussed more in detail.

The problem sounds that it would not be ignition, or most likely fuel and air.

I would recommend looking at the fuel filter, see how old that is. It is likely that the old gas gummed it up and is restricting it.

One way to debunk a system is to use a bit of starter fluid in the intake when the car becomes hard to start. If it starts well, the problem lies in the fuel system. If it makes little/no difference, it is ignition.

I had a 300E that sat awhile and would take FOREVER to start. (almost a half hour total of cranking) Turned out to be a ignition coil.

We would love to hear about any progress and best of luck to you!

-201Freak

 

201freak/// I couldn't hear the fuel pump when I turn on the key to on position for the first time of the day. Is there a particular way to hear it?
Tried the starting fluid and it didn't work. so ignition? how do I check the ignition coil working or not? They are rust free from both ends.

BTW I cleaned up the ICV and now the car idled 10 minutes longer. As it reached 20 minute mark, idle started to fluctuate more and more intense between 500 to 800 rpm. at 27 minute it sputtered and died.

I also checked compression and they all came out between 150 to 190 psi. Unless my method of checking the cylinder compression was wrong, the head gasket is fine.

 

Saying that cleaning out the icv helped you are on the right track I would think, take a look at everything goes into and out of the icv and clean them as well.. may fix your problem. Did you replace fuel filter and are you idling the car with the air intake box top taken off (that would bypass the air filter and would rule that out)

 

And did you open up the cis? There is a diaphragm in there that is notorious for getting gunked up when left full of fuel for extended periods of time when car is left to sit. (same thing with the fuel level float in the gas filler tub) and this may be a silly question but is the fuel level working correctly and is there plenty of fuel in the tank? The way the fuel is pulled from the tank is prone to clogging if left for extended periods without starting as well. Maybe try some lucas oil treatment/fuel cleaner? If times improve odds are the gas sat inside the system too long and draining the tank was not enough to remove everything. Which brings me back to fuel filter, they're cheap to replace. Id start there before tearing down the cis, but after fuel filter is cis...

 

Docwalla// thank you very much. I did not idle the car with air box off. Haven't changed the fuel filter yet. Don't know where it is and have to locate it first. If the fuel filter is clogged, wouldn't I have a hard time starting the car for the first time rather than for the second time as it is now?

So I will have to clean up CIS, replace fuel filter, check duty cycle through x11 connector... So much to do. =-)

 

IT IS VERY IMPORTANT THAT YOU DISCONNECT THE BATTERY ENTIRELY BEFORE YOU START DOING ANY OF THIS BECAUSE YOU WILL HAVE TO REMOVE THE LEADS TO THE FUEL PUMP AND IF THEY TOUCH THEY CAN ARCH AND SPARK IF THERE IS A SHORT IN THE FUEL SYSTEM!

if you did not drain the fuel tank from the line that feeds the fuel rack (fuel pump and filter assembly) then that is most likely why it keeps dying as you didnt fully drain the tank.
it has a reserve built into the tank. (i assume you syphoned out the gas since you dont know where the fuel rack is).

the fuel rack is located under the car in the rear by the axel.

there will be a panel with 4 bolts/screws that are slightly recessed into the panel (socket set needed).
remove that and you will find the main fuel tank line (large rubber line), the return line (smaller rubber line), fuel pump (has 2 wires running to the passenger side), fuel filter (dont quote me, but i believe the arrow should point towards the driver side), and brass connectors.

(BE CAREFUL NOT TO BEND THE BRASS LINES WHEN BREAKING THE FILTER LOOSE! the entire assembly is mounted to 4 rubber connecting bushings so it makes getting good leverage VERY difficult without a strong-handed helper. if you dont mind draining the tank, i would HIGHLY recommend taking the entire assembly down to replace the filter because of this).

remove the air box top (the clamps and 4 bolts in the center/top of the box, then disconnect the cold air intake, remove the sensor and return line at the front of the box, then pull the box completely off to expose the cis system, it will be easy to spot as it has brass lines going to the injectors.)

once the box is off and you have access to the lines; disconnect them all, THEN remove the injector plates.. then the injectors them selves, and check for fouling. (clogged tips)

removing the brass lines feeding the cis system will allow the gas to drain from the top end of the fuel system out of the return line found in the fuel rack, giving you a more complete flush of the fuel system.

before you OPEN the cis you will need to know that when doing so there IS a gasket that will need to be replaced, so until you have the gasket in-hand, ONLY REMOVE THE BRASS LINES!

replace the fuel filter, reattach the fuel rack, return the injectors and plates, as well as the brass lines feeding them.

once everything is connected back up (excluding the air box so that you can check for any leaks in the brass lines while it runs), crank that car over.. it will take a couple tries because the system has to push gas back into the system.
give it a little gas while you crank it. and then see how it runs...

if you need anything else i will be checking back frequently. i love my 190 and its a blast to work on and drive.

have fun and be safe!

-DocWalla

 

also i highly, HIGHLY, recommend that you have a fire extinguisher on hand when doing anything involving gas and the fuel system.. walmart has them for under $20. i have seen someone torch their car, garage, and everything in their garage because they were not taking proper precautions when they did work on their cars fuel system. even with the battery disconnected it is POSSIBLE to ignite the gas/fumes with static electricity or cellphones. so be careful!

 

and as for the starting of the car, if the filter is clogged it could still start and let fuel in before becoming gunked up (which is why it would be hard to start the car after it dies).

 

Doc, Thank you very much for your concerns and advices!

I'm about to work on the car again tomorrow and am studying your tips. I did syphoned the tank through the fuel leven gauge access door on the top of the fuel tank in the trunk. So far the car had been idled for more than an hour. Don't you think idling for an hour would have spent all the bad fuel in the reserve tank?

 

Trying to take the fuel filter off. How can I take the bottom two bolts on the fuel filter? The thinner bolt is too thin for my wrench to hold them properly on top of all those fuel line. It is a 16mm bolt and 16mm wrenches are pretty thick. Because of this another wrench can't sit on the top bolt.

 

the fuel filter should have what looks like a bolt on the end of it, use that and then you should be able to use a set of vice grips to break it loose (from the end with the grips horizontal) it really is easiest to drop the entire rack down because of how fragile the brass lines are, there should be 4 rubber pieces holding the rack up, if you slide those off it should come down, disconnect the fuel lines and the electric leads for the fuel pump and you will be able to remove the rack to work on it and inspect it without a car on your chest lol. (just have something to drain the fuel into when you disconnect the lines) and as for the fuel being burned off in the first hour, yes the bad fuel was burned off, but all the crud that was in the fuel is now trapped in the fuel filter; and when clogged it will deprive the engine of fuel and put a strain on the fuel pump, eventually the fuel pump just sputters to a stop. most of the time when you let the car sit it will start again, but not always. running the car with a severely clogged filter can put stress on the pump and burn it out if not changed.

 

Hello, sorry for the late reply,

If your fuel pump is not turning on like suspected, it could be the pump itself or the MAS relay.

In my 91' 190E 2.6, I can hear the fuel pump prime when I turn on the key to ignition.

If the fuel pump does not prime, then the car might start but would not stay on for long. I've seen a case where the engine would start but die in only a couple of seconds. Why the engine in this case dies after a much longer period of time is beyond me.

If you can find a known good MAS, (Out of a Mercedes with the 6 cyl M103 engine, 190E, 300E, 300E 2.6, 260E, 300SE) and swap them, this might give you some sort of result.

The MAS relay is traditionally located behind the battery near the main computer. It has a strange disconnect where you turn a dial and it pulls the relay out of it's connection. (See attached picture)

If you do not have access to a good MAS, and you are brave, you could override the relay and manually engage the fuel pump. This will at least tell you if the pump and it's connections are good. This can be done by using a jumper on the connection terminal. Here is a link to a thread explaining it:

http://www.peachparts.com/shopforum/...y-failure.html

I would be careful doing this procedure tho.
If the pump does not turn on, check fuses and connections. After that, your pump may need to be refurbed or replaced.

If it is not the fuel pump:
Cleaning the IAC valve might help. An overall fuel system cleaning should do the engine good since it's being sitting for so long.

A friend gave me an idea to do what I call an "Engine Burn" where you fill the gas tank with high octane (93+) gasoline, add a can or two of octane boost and fuel cleaner (Gumout brand preferred, STP works too) This raises the octane to well over 100 (Which is safe for cars for they are design to operate for fuel with octane over 200 without major malfunction)

The idea is to clear the system of debris with the cleaner, then burn it in the exhaust with the high octane fuel. This also clears any dirt out of the catalytic convertor that sometimes get clogged due to low grade fuel.

The best way to execute an "Engine Burn" is to fill up with the three fluids then drive the car on the interstate non-stop until the tank is nearly empty. The high speed allows maximum fuel flow whereas at city speeds the cleaners can't do their job as well.

I'll let the forum discuss this "Engine Burn" before I recommend you do it tho.

I look forward to hearing about your progress,

Good Luck!

-201Freak

 

Did you get the filter replaced? And if so, did it help?

 

Doc, 201//
Thank you very much for your support. I put on a new fuel filter in and the car lasted only for 15 minutes this time instead of 20 - 25 minutes.

when I turn the car key to on position, I hear a brief "zeeeeeeeing" noise from the fuel pump for a second and nothing else. I do not know if this is the priming of the fuel pump you guys are talking about.

I am getting a mechanic's instinct that the fuel pump may be dying. I'm gonna test the MAS to see if it is the fuel pump or not. Thank you so much.

 

If your MAS was bad, the fuel pump would not prime and give you that noise you described. To double check what you are hearing is in fact the pump, have someone turn the key to ignition, but don't start it, while you put your ear by the rear passenger wheel. (The pump is just behind it under the car.)

There is a good possibility that the fuel pump is going bad. One way to check is, when the engine won't start, check a spark plugs for wet fuel. This will tell you if the engine is getting fuel.

Check this video about a stall 300E, which has the 3.0 version of the M103 that a 190E 2.6 has (2.3s are the M102 that are just four cylinder versions of the M103)

Here's part one: Diagnosis

 

Thank you very much 201.

"To double check what you are hearing is in fact the pump, have someone turn the key to ignition, but don't start it, while you put your ear by the rear passenger wheel. (The pump is just behind it under the car.)" I think I already did that. If you re-read my earlier post posted on February 4th... So that humming like "zzzeeeeeeeeeeeeeeeeeeeeeeeeing" noise was it. Right?

 

it sounds like something is being pressurized (like an airbag suspension kinda.. or a ballon on a air tank that you only let air into for a second.). that is normal.

 

and also did you check that the battery is holding a charge? (i know, simple, but could cause it to die out after a while if its not getting recharged by the alternator, also, it could be the alternator. but because you said after you cleaned the icv and it made it better id say its most likely not)

 

Doc, I dropped the fuel pump assembly down and heard the I heard the sound coming from the fuel pump. Not sure if that would had been something else.

 

That's just the fuel pump priming though.