cranksensor

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  #1  
Old 03-06-04, 12:15 PM
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cranksensor

hi everyone,
does anyone know where the cranksensor is located on a
93 grand cherokee ?. have looked hard but not found yet.thanks in advance
 
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  #2  
Old 03-06-04, 03:48 PM
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crank sensor location

You might want to look near the crankshaft pulley/harmonic balancer at the front of the engine. That's where most crank sensors are located because they "count" the RPMs of the crankshaft.

A few GM products are in the block, but the Jeep should be up front.
 
  #3  
Old 03-06-04, 04:28 PM
fordman30
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i agree with smogtek .you have to pull the balancer of to get to it
 
  #4  
Old 03-06-04, 04:50 PM
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Look on the back of the engine on the top of the bellhousing. It will be reading off the flywheel through a hole in the bellhousing.
 
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Old 03-06-04, 08:59 PM
mike from nj
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if WE knew which engine YOU had, WE could help YOU better.


grands usually have a V8, look behind the passenger valve cover, then look down along the firewall, you will see the 1/2" bolts that a socket won't fit on. you need to stick an allen wrench into the bolts(six-sided hex) and i don't know what size either, i have a cut off allen wrench welded into a broken 1/4" socket that works perfect. after it's unbolted, it pulls straight up and out. this is more of a 'feel' job than a 'can see' job, and wait til you try to put the bolts back in

straight 6, 4.0L: this one you get from underneath, on the driver's side of the trans bellhousing, up on top.

like desi said, both of these sensors read off of the flywheel(flexplate).

there's other things that can cause a no-start, are you sure it's this sensor.
 
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Old 03-07-04, 07:04 AM
fordman30
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i thought the one that read off the fly wheel was the knock sensor.
 
  #7  
Old 03-07-04, 03:59 PM
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Originally posted by fordman30
i thought the one that read off the fly wheel was the knock sensor.
Why give advice if you don't know the answer?

The knock sensor is ALWAYS in the block.
 
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Old 03-07-04, 04:56 PM
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thamks for the replies everybody.
mike from nj, sorry, i initially forgot to mention, yes it is a 5.2 V8
and i couldnt find that sensor for the longest time, but you`re right, it is down the passenger valvecover backside. i cant see it, but can feel it, cant imagine how to get a tool down there and not loose the bolts or scuff some fingers.
to your second statement, i went for the cranksensor cause i had good spark and fuel pressure, so i thought. I, at first depressed the little pin on the fuel gauge adapter on the hookup rail to check for gas, and it sprayed out just fine. the next day i tried it it was just getting wet. Cant hear a fuelpump-hum, the pump-relay clicks on at ignition power on, but no fuel pressure.Should i go straight for the fuel pump next? I dont see a fuse for the fuelpump power suypply line. the tank`s almost full and the fuelpump inserts from the top of the tank, what is a good way to get the gas out first?, i think the tank would be pretty heavy trying to lower it down full.
 
  #9  
Old 03-07-04, 06:15 PM
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bad fuel pump?

Mark,

A quick and dirty check for a fuel-related problem is spraying some carb cleaner into the intake while someone cranks over the engine. If you're alone, you can spray then crank it over and should get the same results. If it starts you need to check the fuel system; relay, fuse pump, etc.

BE CAREFUL and GO EASY on the carb cleaner! Flashbacks happen and I don't mean to the 60s.

HTH

Matt
 
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Old 03-07-04, 11:52 PM
mike from nj
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for the record: nothing that chrysler, plymouth, or dodge makes that is rear wheel drive has ever had a knock sensor.


good spark=a working crank sensor, period.

there are a bunch of relays that will click when the key is turned on. if you suspect fuel pressure, the only accurate test is with a gauge hooked up. 40psi would start the car, but would 30psi? how would you even know the difference looking at the size of the spray? some fuel pumps are so quiet, you'll never hear them. even if the pressure drops to zero on the gauge overnight, that's not always bad. zero pressure in the rail with no air is good, zero pressure with the rail full of air is bad. the two second prime(at key "on") should bring the pressure back up, but on a rail full of air, it won't.

try hitting the gas pedal a little(like 1/4 of the way) when it won't start. find the thread about the weak battery (on the dodge V6 i just replied to) it's the same for you.

how old are the plugs and wires/cap and rotor?


let us know
 
  #11  
Old 03-09-04, 11:59 AM
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plugs are new, havent changed cap and rotor yet, but the vehicle ran fine one day and was dead the next.
you said one wont read fuel pressure if there is air in the rail.
if there was air in the fuel rail, how would you purge it out.
there is no fuel pressure left at the gauge adapter plug on the rail.
is there a good way to check power going to the fuel pump besides piercing the wires going to it with a testlight.
the fuelpump relay does come on at key-on.
 
  #12  
Old 03-09-04, 02:14 PM
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I would suggest getting a guage to measure the fuel pressure.Air should purge through the injectors and fuel pressure regulator unless your leaking gas or sucking in alot of air.As far as checking for power some vehicles have a connector near the tank some don't and you may have to lower the tank a little to get at it.While you check for power also test the ground circuit.Don't pierce wires that only causes problems later on and more headaches.If you think it may be the pump beat the tank on bottom with a rubber mallet while someone attempts to start the car.
 
  #13  
Old 03-10-04, 08:52 AM
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err
 

Last edited by markthehermit; 03-10-04 at 12:01 PM.
  #14  
Old 03-10-04, 09:01 AM
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d
 

Last edited by markthehermit; 03-10-04 at 12:00 PM.
  #15  
Old 03-10-04, 11:57 AM
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hi davo, there is zero fuel pressure, i played with the gas pedal while cranking, and also banged on the tank with a mallet, didn`t
bring it back to life. i guess the next step is to get the tank down.
any good way to get the gas out before its all the way unbolted ?
is it possible to get accidental sparks when undoing the locking mechanism on the tank to get to the pump ? i surely wont hit it with a hammer or anything, but if the locking ring is sticky, is it safe to tap it loose to get it off ? (tank is almost full) thanks in advance
 
  #16  
Old 03-10-04, 01:52 PM
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Pretty hard to get gas out of newer tanks.I wouldn't worry about tapping on the lock ring I'm famous for that using a hammer and screwdriver.Make sure you check power and ground before putting a pump in it.Also check the terminals closely for discoloration or looseness.
 
  #17  
Old 03-10-04, 04:22 PM
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I'd try jumping out the relay first before going through all that. Find out if it's a control issue.
 
  #18  
Old 03-11-04, 08:53 AM
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thanks for the tip desi, I already switched the relay (if that is what you mean by `jump`) with a different identical one, no luck, I also sprayed starter fluid in it, engine runs for a second but fuel pressure on the gauge remains zero
 
  #19  
Old 03-11-04, 09:20 AM
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Originally posted by markthehermit
thanks for the tip desi, I already switched the relay (if that is what you mean by `jump`) with a different identical one, no luck, I
No, what I meant was to remove the relay and determine which wires are the power feed and the fuel pump wire and jump them at the connecter to be absolutely sure the power is going back there.
 
  #20  
Old 03-15-04, 08:56 AM
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fixed

I checked power at the relay and then at the connector plug in the back by the tank . had power all the way there. fuel pump was the next culprit in line.
I was able to get the gas out of the tank, disconnected the filler hose and vent hose next to it and was able to get a 1/4 inch sprinkler tubing hose thru the filler hose all the way into the tank and siphoned out my 15 gallons that way (slowly but surely).
a new pump at autozone was $330, a little much, what bothered me a little, the pump did`nt come with a seal ring and they told me they dont sell one either, but the old one was fine (what if it wasn`t ??). other than that, runs fine again. Thanks for the input to my questions to all the moderators and members.
mark
 
  #21  
Old 03-15-04, 04:48 PM
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I generally re-use the O rings. The biggest problem is getting sand and dirt all over it from not bolwing the area clean before removing it.
 
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