rayhennig
Senior Member
- Joined
- Nov 16, 2006
- Messages
- 769
- Reaction score
- 190
- Your Mercedes
- 1991 300CE-24 Sportline
This copied from another forum as I need all the input I can get!
This for the M104.980 engine.
Whining fuel pump and occasional cut-out (but not stall, except for once) prompted me to suspect a fuel pump on the way out. Otherwise, car was starting and running like new. In fact, several people commented on the new (half a million Kms?) car. So we decided to renew everything from tank strainer to the pipe that takes fuel up front.
Pierburg pumps, Bosch accumulator, MB filter and all new hoses from MB.
image1598×1142 169 KB
After what you see here, we aligned all the hoses properly, switched ignition on and looked for leaks. None.
Then, engine on - a few attempts to start - then smooth running. No leaks.
So, job done.
BUT ....
From cold, the car needs 2 attempts to start. On the second attempt, it's exactly as previously, instantaneous.
Thereafter, performance as new. If anything, slightly quicker off the line than with old pumps.
What could be going on here?
Also, last year, I installed a new fuel pressure regulator and that restored the instant start. So, everything is new from tank to fuel distributor.
And the entire metering head/fuel distributor & injectors are all newer than 2017, 80K Kms ago.
Baffled!
Any brainy boys with some ideas?
As an aside, we renewed the tank strainer as we had one in stock. But this is the old one, 33 years old, before I cleaned it up:
RayH
This for the M104.980 engine.
Whining fuel pump and occasional cut-out (but not stall, except for once) prompted me to suspect a fuel pump on the way out. Otherwise, car was starting and running like new. In fact, several people commented on the new (half a million Kms?) car. So we decided to renew everything from tank strainer to the pipe that takes fuel up front.
Pierburg pumps, Bosch accumulator, MB filter and all new hoses from MB.
image1598×1142 169 KB
After what you see here, we aligned all the hoses properly, switched ignition on and looked for leaks. None.
Then, engine on - a few attempts to start - then smooth running. No leaks.
So, job done.
BUT ....
From cold, the car needs 2 attempts to start. On the second attempt, it's exactly as previously, instantaneous.
Thereafter, performance as new. If anything, slightly quicker off the line than with old pumps.
What could be going on here?
Also, last year, I installed a new fuel pressure regulator and that restored the instant start. So, everything is new from tank to fuel distributor.
And the entire metering head/fuel distributor & injectors are all newer than 2017, 80K Kms ago.
Baffled!
Any brainy boys with some ideas?
As an aside, we renewed the tank strainer as we had one in stock. But this is the old one, 33 years old, before I cleaned it up:
RayH
