|
|
|
#1
|
|||
|
|||
300E fuel problem
I am trying to get my 1991 300E (6-cylinder gas) started after a long hibernation. The engine turns over for a short time if I spray carburator cleaner into the air inlet while cranking. I disconnected the fuel line at the carburator and cranked the starter. No gas was coming out. I thought if I could see if electricity was getting to the fuel pumps' leads I could rule out faulty fuel pumps. No electricity at the fuel pump lead while cranking. I am assuming there is a relay of some sort between the battery and the fuel pump, but im not sure where it is or how to test it. I would really appreciate any insight.
|
#2
|
|||
|
|||
On USA versions the fuel pump relay is part of the MAS system relay.
Removing the relay & bridging pins 1 & 2 will run the pumps
__________________
MERCEDES Benz Master Guild Technician (6 TIMES) ASE Master Technician Mercedes Benz Star Technician (2 times) 44 years foreign automotive repair 27 Years M.B. Shop foreman (dealer) MB technical information Specialist (15 years) 190E 2.3 16V ITS SCCA race car (sold) 1986 190E 2.3 16V 2.5 (sold) Retired Moderator |
#3
|
|||
|
|||
300-E fuel problem
I removed the MAS module and put a wire between the #1 and #2 sprockets with the ignition off expecting to hear some whining or something from the area of the fuel pumps but heard nothing. There was a bit of sparking. Should I be expecting a different result?
|
#4
|
|||
|
|||
I bridged the female part of the socket from the 1 port to the 2 port with a bit of wire. This resulted in fuel pressure at the injector. I assumed that meant that the MAS module is faulty so I replaced it. Now I am back to having zero fuel at the injector while cranking. If there are no other components involved I am beginning to wonder if it is likely that the fuel line is clogged, perhaps at the filter? Does anyone have any ideas?
|
#5
|
|||
|
|||
clogged filter ?
A fresh fuel filter will give you a good check from the fuel source . The adjoining fuel accumulator will be very easy to replace at the same time.
mak |
#6
|
|||
|
|||
no spark now
I replaced the MAS relay and have fuel pressure at the injector. Now when I try to crank, it appears that I have no spark, so I am going backward. I had been using jumper cables while test starting and I read that the OVP relay could be adversely affected by jump starting. I have replaced the battery, and checked the fuse on the OVP. The fuse is not blown. I checked the Distributor cap and rotor, and it looked okay. If anyone has any ideas on what to try, I would really appreciate some guidance.
|
#7
|
|||
|
|||
Possibly in the OVP relay a solder track near the big zener diode may have been damaged due to the jump. re solder if so.worked for me .
mak 300se 103 |
Bookmarks |
|
|