om603 won't idle
om603 won't idle
Untill then, any ideas on why it wont idle?
NapaBavarian
05-26-2014, 12:01 AM #1I picked up this non running 87 300sdl in san francisco a couple days ago and after some work I got it running, was a loose hose clamp at the lift pump. I cleared gobs of air from the fuel system and it warms up nicely at 2000rpm witth my foot on the throttle, but as soon as I take my foot off the acelerator it just dies and must start it with foot on the floor. The tank is full of mystery fuel, I have no idea what it is, but I see signs of wvo and smell possible motor oil in the clouds of smoke and it looks thick, I'm thinking of thinning it with some gasoline and then using a more acceptable fuel.
Untill then, any ideas on why it wont idle?
(05-26-2014, 12:01 AM)NapaBavarian Untill then, any ideas on why it wont idle?
Oh, maybe a few...
(05-26-2014, 12:01 AM)NapaBavarian ...The tank is full of mystery fuel, I have no idea what it is, but I see signs of wvo and smell possible motor oil...
You answered your own question haas. Mercedes no likee mystery!
Easy confirmation, grab a fuel can or even an empty water/gatorade container and fill with D2 (or DieselPurge if possible.) Route the fuel feed and fuel return lines into bottle filled with diesel. Replace the secondary (spin-on) filter, filling it with fuel prior to screwing it on. Start and run. Same symptoms? If no idle as before, methinks you have lots of $$$ fixes and/or headaches in your future. If engine idles without assistance, you may just getaway with a fuel tank and strainer power cleanse and filters replacement. Keep spare filters handy, you'll be flushing your car's plumbing of the po's thoughtful gifts for some time to come. Enjoy.
Report back when done.
MBZ123
(05-26-2014, 12:01 AM)NapaBavarian Untill then, any ideas on why it wont idle?
Oh, maybe a few...
(05-26-2014, 12:01 AM)NapaBavarian ...The tank is full of mystery fuel, I have no idea what it is, but I see signs of wvo and smell possible motor oil...
You answered your own question haas. Mercedes no likee mystery!
Easy confirmation, grab a fuel can or even an empty water/gatorade container and fill with D2 (or DieselPurge if possible.) Route the fuel feed and fuel return lines into bottle filled with diesel. Replace the secondary (spin-on) filter, filling it with fuel prior to screwing it on. Start and run. Same symptoms? If no idle as before, methinks you have lots of $$$ fixes and/or headaches in your future. If engine idles without assistance, you may just getaway with a fuel tank and strainer power cleanse and filters replacement. Keep spare filters handy, you'll be flushing your car's plumbing of the po's thoughtful gifts for some time to come. Enjoy.
Report back when done.
MBZ123
It seems this car had straight wvo in the tank, just dark and unwashed. Even straight wvo runs in a warm engine.
I did manage to purge the fuel system with good biodiesel, I now have a biopro190 that does wonderes.
Back to the origional question. Idle. The engine runs fine and smokes enough to cure a heard of cattle carcasses.
Can someone tell me about the idle circuit? What makes it work? What might cause it to not work? Could misconnected electrical or vacuume cause it to fail to function? any adjustments?
NapaBavarian
05-26-2014, 04:59 PM #3Mysterys aren't so bad, been using them for years, and the head seems fine so $$$ should stay with me.
It seems this car had straight wvo in the tank, just dark and unwashed. Even straight wvo runs in a warm engine.
I did manage to purge the fuel system with good biodiesel, I now have a biopro190 that does wonderes.
Back to the origional question. Idle. The engine runs fine and smokes enough to cure a heard of cattle carcasses.
Can someone tell me about the idle circuit? What makes it work? What might cause it to not work? Could misconnected electrical or vacuume cause it to fail to function? any adjustments?
Duncansport
05-27-2014, 02:42 PM #4Check the overvoltage relay's fuse. If its out the ELR wont receive power and thus it will only idle slowly or stall.
Try to run pure diesel from a container or something like previously said. I bet it will solve the problem.
Oh yeah and spin on a new fuel filter.
I've used my car for some time without elr. The revs where lower than usual but no stalling. The idle rpm is controlled by some weights in the governor and can be adjusted with the screw at the very top of the governor. I thought turning it out means higher idle rpm's.
Try to run pure diesel from a container or something like previously said. I bet it will solve the problem.
Oh yeah and spin on a new fuel filter.
NapaBavarian
05-27-2014, 05:01 PM #6It has a new filter and a mason jar of the good stuff under the hood. Ill check that fuse when I get home. Is it in the fuse box?
As tito mentioned, idle speed control is entirely mechanical without the elr connected and will control engine idle just fine. The adjustment is pointing rearward just above and forward of the red elr cover at rear of pump. Has a locknut. Your issue IS NOT the idle governor (or elr either.)
(05-26-2014, 04:59 PM)NapaBavarian Back to the origional question. Idle. The engine runs fine and smokes enough to cure a heard of cattle carcasses.
Don't know your definition of fine, but doesn't seem to me as if your engine runs fine. If so, it would A) idle on its own and B) not send smoke signals to mars. The purpose of redirecting the fuel lines (feed&return) into a container of d2 after renewing the filters is to eliminate what is most likely your problem. A plugged fuel system. Biggest clue is the need for pedal to keep it going. Results from running the engine with a temporary fuel source gets you to your solution the quickest.
If there is evidence of straight veg being run through this motor you need to prepare for the worst. It could end up a long journey of pricey repairs or you could get lucky and just have to flush the fuel tank and buy all new hose. I'm quite aware svo will burn in a diesel engine as I've tried just about every fuel that can. You need to be concerned with the issues specific to longer term svo use in a sub-par system setup.
Also, just curious, what exactly are you referring to as "dark and unwashed?" The inside walls of the fuel tank itself or what the tank is filled with? I hope you mean the inner surface of the tank because "unwashed" to me describes a fuel with particulate and water in it. That's BAD NEWS all day long. Most likely couldn't be seen in an installed tank, though. Regardless, you'll need to remove the tank and make sure it is properly flushed OR you will be dealing with this or similar issues over and over and over. Don't waste your time or money with cure-alls in a bottle. Do it right.
MBZ123
The OVP relay is in that space between engine compartment and firewall, sitting adjacent the klimarelay and has the RED hinged cover. Your issue IS NOT electrical.
As tito mentioned, idle speed control is entirely mechanical without the elr connected and will control engine idle just fine. The adjustment is pointing rearward just above and forward of the red elr cover at rear of pump. Has a locknut. Your issue IS NOT the idle governor (or elr either.)
(05-26-2014, 04:59 PM)NapaBavarian Back to the origional question. Idle. The engine runs fine and smokes enough to cure a heard of cattle carcasses.
Don't know your definition of fine, but doesn't seem to me as if your engine runs fine. If so, it would A) idle on its own and B) not send smoke signals to mars. The purpose of redirecting the fuel lines (feed&return) into a container of d2 after renewing the filters is to eliminate what is most likely your problem. A plugged fuel system. Biggest clue is the need for pedal to keep it going. Results from running the engine with a temporary fuel source gets you to your solution the quickest.
If there is evidence of straight veg being run through this motor you need to prepare for the worst. It could end up a long journey of pricey repairs or you could get lucky and just have to flush the fuel tank and buy all new hose. I'm quite aware svo will burn in a diesel engine as I've tried just about every fuel that can. You need to be concerned with the issues specific to longer term svo use in a sub-par system setup.
Also, just curious, what exactly are you referring to as "dark and unwashed?" The inside walls of the fuel tank itself or what the tank is filled with? I hope you mean the inner surface of the tank because "unwashed" to me describes a fuel with particulate and water in it. That's BAD NEWS all day long. Most likely couldn't be seen in an installed tank, though. Regardless, you'll need to remove the tank and make sure it is properly flushed OR you will be dealing with this or similar issues over and over and over. Don't waste your time or money with cure-alls in a bottle. Do it right.
MBZ123
Untill then, any ideas on why it wont idle?
NapaBavarian
05-29-2014, 01:15 PM #8I picked up this non running 87 300sdl in san francisco a couple days ago and after some work I got it running, was a loose hose clamp at the lift pump. I cleared gobs of air from the fuel system and it warms up nicely at 2000rpm witth my foot on the throttle, but as soon as I take my foot off the acelerator it just dies and must start it with foot on the floor. The tank is full of mystery fuel, I have no idea what it is, but I see signs of wvo and smell possible motor oil in the clouds of smoke and it looks thick, I'm thinking of thinning it with some gasoline and then using a more acceptable fuel.
Untill then, any ideas on why it wont idle?
I have tested the relay on the firewall by swaping it with another and I will pull and pop test the injectors, hopefully this weekend, I have been able to hold the rpm at 1000-1200 but if I dip below that it falls appart, sometimes I snap the throttle open and it picks up, sometimes it dies. It freely revs up to 4700-5000 rpm, there is excessive smoke uppon startup, but if I run it for 5 minutes it mostly goes away. Still excessive but not what it is on startup.
NapaBavarian
05-29-2014, 11:02 PM #9I'm going to try to pick up where I left off since the last thread got a little hijacked, the fuel system has been flushed and filters were replaced after all mystery fuel was flushed, the symptoms remain the same.
I have tested the relay on the firewall by swaping it with another and I will pull and pop test the injectors, hopefully this weekend, I have been able to hold the rpm at 1000-1200 but if I dip below that it falls appart, sometimes I snap the throttle open and it picks up, sometimes it dies. It freely revs up to 4700-5000 rpm, there is excessive smoke uppon startup, but if I run it for 5 minutes it mostly goes away. Still excessive but not what it is on startup.
Duncansport
05-30-2014, 11:55 AM #10Check the pump timing yet? Check those injectors for pop pressure as well. Does it nail when idling? How's it start? Has it been a WVO car for a while? How much blow by?
I have not yet checked timing, I'll look for a writeup on that if I can find one.
It seems to be running better, less smoke, a little nailing just as it starts then it's quiet, normal. I havent looked at blowby since I cant get out of the car when it is running but I'll try as soon as I get a chance
NapaBavarian
05-31-2014, 06:27 PM #11It sounds fine, normal, after a bit of thinking the best way I can describe startup is every time I start it the symptoms are similar to starting a car that has been run out of fuel and still has a touch of air in the system. I have no history on the car but I've been running it 10 minutes or so once a day in hopes that if there are deposits or gummed up internals it will disolve whatever is in there, I'm using biodiesel so it will clean things up nicely.
I have not yet checked timing, I'll look for a writeup on that if I can find one.
It seems to be running better, less smoke, a little nailing just as it starts then it's quiet, normal. I havent looked at blowby since I cant get out of the car when it is running but I'll try as soon as I get a chance
DiseaselWeasel
06-01-2014, 11:46 AM #12Is the top of the pump wet? Does it start better when it's parked nose down?
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