1994 mercedes s500. The fuel is good, it cranks, but no sparks on the spark plugs. What can is the problem? please let me know throuth email: [email protected] Many thanks Bing

that post makes little sense.
#5 and 6 means what? add 1 noun please.
spark is good to all 6 cylinders.
no fuel out of all injectors.
THe ECU spark the spark plugs
and if the ECU sees gross spark errors it cuts fuel ,hard pure logic in the ECU does that and by law
ever to the 1994 ECU DTC diagnosic jumper flash code tests
in the service manual>

this is a gasoline engine (petrol Otto cycle rules) and as such
engine must be good first. 150psi compression x6 is good
and next is spark good on all 6 , not just 1,
how many spark coils are there, 1994. (spark tech changes fast then)
the 4.0 has 6 lug HV terminal coil pack and must not be wired up wrong because this coil pack as 3 coils inside, called wasted spark
and if wired wrong 2 or 4 or more spark plugs fail for firing order.
and time. they still spark but at the wrong time.
not the distributor version but is DIS system.I am taking, vin X

Vin -8th = X 4.0, no distrib.
if engine was good, and spark was good even a fully dry fuel TANK
test fuel works now, (spray instant starter fluid) for 3 seconds. each try.
i bet yours fails that test. or sounds horrible misfiring badly.
crank senors dead
cam sensor dead. (cam shaft synchronizer, seen where old disributor was older year) either sensor dead, FUEL IS CUT by LAW.



do not mix up the wires or doomed misfire grossly.

Codes help. But you need to check what you don't have. Fuel pressure or spark at the coils/plugs. I know you replaced them, but it could be a bad wire, plug, or fuse. Could be a bad ECU.

Crank position sensor?

does that mean it CRANKS robustly, if not? fix no crank or post that.
1994 trooper. (not starting wide open throttle to clear flooding>?)
is the 4JG2 is a 3.1 L (3,059 cc), EFI engine. V6.
this is 1 of 9 engines , used,
i think this 3.1 has a distributor ,
so does the cap off, rotor spin cranking, if not , the cam chain snapped.
next, is spark (i do compression first, but im odd that way, on old iron)
i check spark. i check it to all 6 cylinders using the time honored system. we all know, right>? with a fresh test spark plug, gapped correctly. got spark.
are you spark plugs old , never did the 60k mile tune ups, (repeats)
if the spark parts are old ,no car runs right.
you know the ,ole' cap,rotor,wires , sparks filters deal.'
the we check fueling.
i look at the spark tips, are the dry,? i try the test fuel test.
if car runs for 3 seconds on test fuel the engine fuel system is dead.
check fuel pressure next.


watch scotty do his magic.

http://www.youtube.com/watch?v=064Ilsz8Fzg&NR=1&feature=fvwp

don\'t understand: cranks fast enough (battery low??) or crank at all??. Need more detail(s);if it cranks at all but slow,you won\'t get a spark;don\'t touch the end of the spark plug wire \'cause it\'d make your butt pucker if/when you get spark!!! honestly.

does the motor crank. if it cranks the starter and altnator are good. now when you turn the key to the start position do you hear the fuel pump? do you know if you have spark at the spark plugs

check for spark and then check for fuel

Check for spark; pull the plug fom the coil, place @ 1/4" from grounded metal, crank over and look for spark.

Please let me know wat you find.

Thanks,
Tom

Malfunctioning fuel system.
Fuel injector[s] leaking...check fuel pressure,more then 53psi
check fuel injector resistance / ohms/
Ignition component damp or demaged.Checks wires broken,loose or disconnected in the starting circuit.Worn, faulty spark plugs.....

Check if you have sparks. 1- If there is no spark, check the coil for replacement. 2- If there is spark then there is a problem with the cold start valve. It is a normal close valve and only open during the cranking. When it is bad, it normal open the too much fuel coming in wetting all spark plugs before a combustion taking place. Good Luck.