No start issues with my '99 E300TD - PeachParts Mercedes-Benz Forum

Woofwagon · #1 07-03-2015, 09:29 PM

Greetings,

I purchased this car in April '15 to use as a commuter as the VW TDi cars are much too cramped for my large frame. The engine is the OM606 Turbo.

A few weeks ago I ran into an issue of the EGR being blown by a clogged catalytic converter. The car had no power and was blowing exhaust out the EGR valve due to the constipated catalytic. These symptoms happened very suddenly, there was no gradualism. $2700 bucks later the mechanic still cannot get the car to start or run for more than a few seconds. I told him no more money until he gets the car running.

What could be causing this issue? I have checked the MAP and its twin by the ABS brake controller (still learning the names for things), I have replaced the intank fuel screen (that was clean as a whistle), I see no undue air bubbles in the clear fuel lines.

Your input on this no start issue would be appreciated.

Thanks

Does the car have to have its ECU reset before it can recover from a seriously clogged catalytic converter? I mean this thing was packed solid.

Woofwagon · #2 07-03-2015, 09:35 PM

Addendum: even with the turbo disconnected from the catalytic and no back pressure what so ever the engine will not run for a few seconds.

TMAllison · #3 07-04-2015, 10:31 AM

Confused, will it start and run for 2 secs or does it never start?

Sans any major fuel/air leaks at the fuel lines or delivery valves, I'd concentrate on fuel supply and electronics controlling it. The shut off valve (electro-magnetic valve) on the side of the IP and the movement of the rack inside the IP.

The MAP is a small 1" x2" black box with a vacuum line leading down to the EGR valve 12" away. It is mounted on the drivers side firewall.

There are two vacuum transducers, one next to the ABS controlling the EGR valve, and the second under the air filter box controlling the waste gate.

Murkybenz · #4 07-04-2015, 10:42 AM

Is the ecu getting a signal from crank sensor ?, it will run and fire when cranking on key but will shut down if no signal from sensor

jay_bob · #5 07-04-2015, 12:07 PM

Dumb question-

What OBD codes is it throwing?

I would start with a basic scanner. Although the data passed to a basic scanner is very limited. If it comes up empty I would find someone with a HHT or Xentry to scan the system for issues.

Woofwagon · #6 07-04-2015, 03:57 PM

Quote:

Originally Posted by TMAllison

Confused, will it start and run for 2 secs or does it never start?

Sans any major fuel/air leaks at the fuel lines or delivery valves, I'd concentrate on fuel supply and electronics controlling it. The shut off valve (electro-magnetic valve) on the side of the IP and the movement of the rack inside the IP.

The MAP is a small 1" x2" black box with a vacuum line leading down to the EGR valve 12" away. It is mounted on the drivers side firewall.

There are two vacuum transducers, one next to the ABS controlling the EGR valve, and the second under the air filter box controlling the waste gate.

I swapped the two vacuum transducers and replaced one of them in the hopes that was the problem. I don't know if the map sensor could have been blown by the EGR going kablooie. If there was excessive pressure applied to the MAP from the EGR that could be a possibility. The car won't run for maybe a second and a half and shutoff. I'll look into the SOV possibility with the mechanic. Sounds kind of stupid that so many problems would be generated due to a clogged catalytic converter.

Woofwagon · #7 07-04-2015, 03:58 PM

Code thrown was P0243, a boost circuit error.

jay_bob · #8 07-04-2015, 04:35 PM

On the top of the forum page there is a Search button. Click that but instead of using the search box that appears, use the Advanced Search link. That search works much better.

Lots of hits on P0243. Be sure to use P 'zero' 243 not P 'upper case O' 243.

I'm thinking bad MAP sensor. Once the thing starts spinning and fires, the only thing that will stop it is if it's denied fuel. The computer must be shutting down the party when it sees something it doesn't like once the engine fires.

The only things the computer controls on this engine are the IP rack, the fuel solenoid, and the two vacuum transducers.

Woofwagon · #9 07-04-2015, 04:50 PM

Thanks, Jay Bob. I will do that here shortly. The CEL wasn't coming back on after I reset the code. To confirm, the MAP sensor is on the driver's side of the engine compartment near the brake master cylinder?

Skid Row Joe · #10 07-04-2015, 04:51 PM

Quote:

Originally Posted by Woofwagon

Greetings,

I purchased this car in April '15 to use as a commuter as the VW TDi cars are much too cramped for my large frame. The engine is the OM606 Turbo.

A few weeks ago I ran into an issue of the EGR being blown by a clogged catalytic converter. The car had no power and was blowing exhaust out the EGR valve due to the constipated catalytic. These symptoms happened very suddenly, there was no gradualism. $2700 bucks later the mechanic still cannot get the car to start or run for more than a few seconds. I told him no more money until he gets the car running.

What could be causing this issue? I have checked the MAP and its twin by the ABS brake controller (still learning the names for things), I have replaced the intank fuel screen (that was clean as a whistle), I see no undue air bubbles in the clear fuel lines.

Your input on this no start issue would be appreciated.

Thanks

Does the car have to have its ECU reset before it can recover from a seriously clogged catalytic converter? I mean this thing was packed solid.

Has the intercooler been checked for oil that may have leaked into it?

TMAllison · #11 07-04-2015, 05:04 PM

The CPS idea has some merit, is on top of the trans down below the oil filter canister. K40 relay could also be at fault cutting power to various devices/sensors (CPS, Rack, etc). Lack of a code being set always makes it a suspect.

Woofwagon · #12 07-07-2015, 10:21 AM

Update: Mechanics tested the K40 and CPS for proper function and test range. Both were within the manufacturer's spec.

One thing I noticed was that the clear fuel lines were not filling or purging any air. I then described to the mechanics to rig up a "transfusion bottle" to feed the engine with fuel with the lift pump taken out of the loop. This way, if the engine fires and runs, it will directly point to the lift pump. I'm thinking that after 122K miles that pump has finally given its last.

Shame a clogged catalytic converter would cause this cascade of events. Hopefully this will get my car back to me. The shop is tired of pushing it around, they want to see it fixed as much as I do.

shertex · #13 07-07-2015, 10:26 AM

How many miles on the car?

TMAllison · #14 07-07-2015, 10:38 AM

Lift pumps rarely go fail, not at all common.

If you don't have fuel visible in the fuel lines you have a leak allowing air into the system.

Line #1 (fuel thermo/pre-filter) will drain back an inch or two at shutdown, the rest shouldn't. fuelflow.JPG (image)

dude99 · #15 07-07-2015, 12:56 PM

Quote:

Line #1 (fuel thermo/pre-filter) will drain back an inch or two at shutdown, the rest shouldn't.

You have no idea how much time you may have just saved me trouble shooting that. I've been fighting air leaks and thought I still had one because that line kept draining back...