|
|
|
|
|
#1
08-27-2011, 11:43 PM
|
|||
|
|||
|
Some fuel pressure questions - '86 560SL
I have been chasing down a WARM start problem for several months - car will start up warm, but it will not go anywhere when you press on the gas pedal - and if I don't let off the gas it will just stall out. Sounds like gas is boiling in the tank...idle is very rough, chugging along for several minutes. Once it gets past this, car runs great.
Anyway, I have some simple fuel pressure test results questions...tested the fuel pressure and all my readings were spot on (see my post on the Tech board), and no leakdown noted. The system held pressure above 3.0 bar for hours (manual says it must hold for 30 minutes). Questions: Does this rule out the fuel pump check valves and the fuel injectors - since I'm not losing pressure? Does it rule out a bad gas cap? (I replaced the accumulator, thinking it was the obvious problem... ryan
__________________
RG Newell 1984 300D 1972 250 1986 560SL 1991 300CE 
|
|
#2
08-28-2011, 04:47 PM
|
||||
|
||||
|
when were the injectors serviced last, changed? That would be my next step , providing pressures are good, they could have bad or non existant spray patterns. Air flow sensor plate has been checked for binding - correct/
__________________
Ron 2015 Porsche Cayman - Elizabeth 2011 Porsche Cayman - Bond,James Bond Sadly MERCEDESLESS - ALways LOOKING ! 99 E320 THE Queen Mary - SOLD 62 220b - Dolly - Finally my Finny! Sadly SOLD 72 450SL, Pearl-SOLD  16 F350 6.7 Diesel -THOR 19 BMW X5 - Heaven on Wheels 14 38HP John Deere 3038E Tractor -Mean Green 84 300SD, Benjamin -SOLD 71 220 - W115-Libby ( my first love) -SOLD 73 280 - W114 "Organspende" Rest in Peace 81 380 SL - Rest in Peace
|
|
#3
08-28-2011, 05:20 PM
|
|||
|
|||
|
Thank you for the reply, but I'm not sure I follow...the car runs great in every other way - accelerates great, runs at 75 w/o any problems and I'm getting to be expected mileage.
How does 'bad, or non-existent spray patterns' contribute to this warm start issue? I want to know that if my fuel pressure test does NOT indicate any leaking down of pressure - can I rule out injectors, fuel pump check valves etc??? It "seems" to me that this warm start problem could be related to leaky injectors, but it does not appear that I have any injectors leaking down... ryan
__________________
RG Newell 1984 300D 1972 250 1986 560SL 1991 300CE
|
|
#4
08-28-2011, 05:37 PM
|
||||
|
||||
|
the injectors do not have to leak to be bad. They can however have a poor spray pattern that does not atomize the fuel so the combustion is less than it should be,one or two may be spraying a stream causing too much fuel. How many miles on them? Are you running rich ? what color are the plug tips?
I would agree that your check valves and fuel pump could be ruled out
__________________
Ron 2015 Porsche Cayman - Elizabeth 2011 Porsche Cayman - Bond,James Bond Sadly MERCEDESLESS - ALways LOOKING ! 99 E320 THE Queen Mary - SOLD 62 220b - Dolly - Finally my Finny! Sadly SOLD 72 450SL, Pearl-SOLD 16 F350 6.7 Diesel -THOR 19 BMW X5 - Heaven on Wheels 14 38HP John Deere 3038E Tractor -Mean Green 84 300SD, Benjamin -SOLD 71 220 - W115-Libby ( my first love) -SOLD 73 280 - W114 "Organspende" Rest in Peace 81 380 SL - Rest in Peace
|
|
#5
08-28-2011, 05:42 PM
|
|||
|
|||
|
Car has 84K, new plugs within the last 10K miles, but I haven't pulled them recently. Mixture checked and reset within the last week to try and fix a surging idle problem, so I don't think I'm running rich.
Injectors have not been serviced since I have had the car (3 years)...
__________________
RG Newell 1984 300D 1972 250 1986 560SL 1991 300CE
|
 |
| Bookmarks |
| Thread Tools | |
| Display Modes | |
|
|
Linear Mode
