Starting problem on my 1996 Mercedes E320

Maintenance/Repairs
1

I have a issues with starting my 1996 mercedes E320
When its cold it starts right up, but when engine hot it will not start easy, it cranks good but i have to pump the gas pedal few times and then it will fire up.
Any suggestions.
Thanks.

2

Could be a leaky injector causing flooding. Holding the gas pedal down all the way while cranking should clear that up within a few seconds if that’s the case. Good luck and please let us know.

1 Like
3

Have the fuel pressure tested.

If the fuel system doesn’t hold residual fuel pressure when the engine is shut off when hot, the fuel in the fuel rails will boil causing vapor lock.

Tester

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4

So if it doesn’t hold the pressure, fuel pressure regulator gone bad?
Thanks

5

So if it fires right up when hot with pedal down, dripping injector?
I’ll try that , will let you know. Thanks.

6

More than likely the anti drain-back check valve on the fuel pump is faulty.

Tester

7

If there were a leaking fuel injector, only one cylinder would not fire immediately. But the other cylinders would fire right up

So that’s not it.

Tester

8

Thank you. I’ll check that out

9

Holding pedal down didn’t help much,
It usually works pumping the pedal while cranking.
But when is cold engine no problem whatsoever.

10

A fuel pressure hold test would prove/disprove a leaky injector or fuel pump check valve problem. That’s probably the first thing to ask your shop to do. If the fuel pressure is correct & holds ok but it won’t start right up, other common heat-affected parts are the ignition module and the crank position sensor. Have you checked for engine diagnostic codes? There cold be some stored even if the check engine light is off.

11

No codes , i’ve checked that, will try test fuel pressure and go from there.
Thanks