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1994 Mercedes-Benz 300 Series Base 4dr Sedan 3.2L Auto

1994 Mercedes-Benz 300 Series
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June 2, 2011, 5:44 pm

Albert C

Question: Spraying fuel through air intake ?

Will not start. ...was running perfect...
checked spark removing 2 plugs.....good white spark upon cranking engine few turns....

suspect no fuel into injectors....
can I confirm by remove air filter cover....pushing down on round plate a bit deep with wood ruler....cranck engine..spray gasoline into cavity as engine rotating........see if engine will fire up ??

do I have to pull out relay next to battery....big rectangular alumin. box has knob on top can turn to 0 or I........(..0 to remove.....) ???

June 7, 2011, 9:54 am

Elizabeth K

What you're describing is the fuel distributor (round plate). Don't mess with that. Check the fuel pump relay first, they're usually the problem.

For locations and procedures, check out the free, online repair manuals on the website. If you're planning on doing work on your car in the future, investing in a factory manual is a good idea.

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June 9, 2011, 5:48 pm

Albert C

my fuel pump will hum about 5 sec when i turn key on.....

good spark on plugs checked........engine cranks....but will not start....
so if pumps hum....means F P. relay ok. because is getting signal from ignition through the relay all the way to pumps.......

if i disconnect fuel line into injector distributor house....and turn on it correct fuel shoul flow out of disconnected end ???

if no fuel...then possible fuel filter clogged ??

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June 10, 2011, 6:35 am

Elizabeth K

If you're due for a fuel filter, then replace it, but fuel filters initially cause bogging down on acceleration for a while, it is unlikely to cause a problem like yours where it went from running fine to not starting.

Yes, you can disconnect the fuel line and crank it, but fuel pressure on jetronic systems is MUCH higher than on american/japanese cars. Copious amounts will come out, and the pressure is lower at the fuel injectors and further back in the circuit, so that is a good place to disconnect. But if you want to try spraying some ether into the intake, the best way to do it is unhook a vacuum line and spray into it (the idea is not to introduce a vacuum leak). And moving the round plate in the fuel distributor will directly affect the fuel metering, and could bend an adjustment spring, so avoid messing with that unless you're carefully cleaning it.

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