|
rhd280
Regular
Date registered: Dec 2014
Location: New Zealand
Vehicle(s): 1982 280GE LWB RHD
Posts: 67
| Need advice on hot starting W460 280GE
My 1982 280GE starts fast when cold. But after driving for a while, if I shut down, it almost starts for a second, and then I have to crank for 20 seconds or so, sometimes pumping accelerator to get it to start. Thankfully it has a new battery, so eventually it starts.
Clearly it is a fuel problem, but before I crack into it, I am hoping for someone to point me in the right direction. The G has 400,000 miles on it, I've owned it 25 of its 40 years and the fuel pump buzzes when I turn the key, so I know it is pushing fuel in. I don't know much about Bosch fuel injection, but am good with a wrench. |
|
| |
|
J.R.
Elite Veteran
Date registered: Apr 2006
Location: Southern Maryland
Vehicle(s): 00 G500, 09 911 4S, 11 Cayenne S, 86 280GE (sold)
Posts: 829
| Re: Need advice on hot starting W460 280GE
My first guess is that somewhere between the fuel pump's check valve (on the output side) and the pressure regulated return valve is leaking causing the loss of pressure. Retaining the pressure after shutdown helps prevents vapor lock.
it can be one of the check valves, a leaking fuel injector or a leaking cold start injector.
It would be best to put a fuel pressure gauge in line on the high pressure side and monitor what happens after shut down.
Other guesses: fuel pump health and fuel pump relay (albeit quite small likelihood but easy to test). |
|
| |
|
G-AMG
G-Class DIY Host
Date registered: May 2006
Location: South Texas
Vehicle(s): '04 G55, '80 280GE, '99 S420, '98 E320, 2011 E350
| RE: Need advice on hot starting W460 280GE
Ya. I have the same issue. What I hear? It is a common problem, even on the M110 sedans.
What "I" do? Hot-Restart is done with accelerator in an approximate " 1/4 Open " position.
If this does not work, and you really need to do fuel system, here is a DIY:
http://pointedthree.com/disc/forums/showthread.asp?tid=21986&posts=... |
|
| |
|
Otiswesty
Administrator
Date registered: Jun 2007
Location: Portland, Oregon
Vehicle(s): 463.241, 461.213
Posts: 3018
| RE: Need advice on hot starting W460 280GE
Run it to hot and shut down, check fuel pressure after 20 min. Fuel pressure should be maintained by the spring diaphragm in the fuel accumulator next to the fuel filter in back. When these go bad it can lead to similar symptoms. I just read an old post of Dave's (Hipine) a few days ago on this subject
CSV only works when the engine is cold for extra fuel at cold start as I understand it.
Possibly the WUR is the culprit as well, I recently got a brand new unit from MB that was less expensive than the estimate for rebulding mine at CisFlowTech here in the USA.
The new WUR is on the right in the first pic.
I have not touched my fuel accumulator, but replaced the WUR and AAV when I had my intake manifold off last year.
 (WURs.jpg)
 (WURin.jpg)
Attachments
----------------
 WURs.jpg (130KB - 46 downloads)
WURin.jpg (130KB - 49 downloads)
|
|
| |
|
Otiswesty
Administrator
Date registered: Jun 2007
Location: Portland, Oregon
Vehicle(s): 463.241, 461.213
Posts: 3018
| RE: Need advice on hot starting W460 280GE
Here is a similar discussion
http://www.pointedthree.com/disc/forums/showthread.asp?tid=17966&st... |
|
| |
|
rhd280
Regular
Date registered: Dec 2014
Location: New Zealand
Vehicle(s): 1982 280GE LWB RHD
Posts: 67
| RE: Need advice on hot starting W460 280GE
Any advice on how to make a DIY fuel primer - in other words, run a hose to the fuel injection intake (W460), press a button on the dash, and a squirt of petrol primes the engine.
The alterative of a complete analysis of why the engine does not fire up when hot and then shut down for a while is not cost-effective for a vehicle that is lucky to get 600 miles a year of driving. It instantly almost fires, then I have to crank for 20 seconds. Works because it has a good battery, but it's hard on the starter motor. Squirting ether works, so I reckon one of the old time prime-the-engine devices on the dash would do the same job from within the cab. |
|
| |
