Urgent: No fuel pump

[CharlesS]

The Cam Position Sensor is probably bad....
The Cam Position Sensor is located inside the distributor and sends a signal to the ECM when the plugs fire so it can pulse the injectors...
I know this because it happened to me last summer....

 

[97XJ2]

So what does the Crank position sensor do then?

 

[CharlesS]

The Crankshaft Position Sensor senses points on the flywheel which provides the ECM with what cylinder is coming up in the cycle....

The ECM needs feedback from both CPS's to sequence the fuel injectors with the firing of the sparkplugs....

 

[97XJ2]

Ok so the plugs are dry. Injectors not firing then. What would dry plugs have to do with compression? Cam position is the next culprit then.

 

[97XJ2]

And napa doesn't carry the Cam position sensor? WTF

 

[89xj]

And napa doesn't carry the Cam position sensor? WTF

they may call it someting different. on my 89 its called a stator or sync signal generator.

just checked rock auto and i think they call it the distributor ignition pickup.

 

[97XJ2]

The guy at car quest was smart enough to be able to link "cam position sensor" and "pickup sensor" together after he asked the location. So my CPS is coming in via car quest tomorrow in the AM

 

[89xj]

napa part

http://www.napaonline.com/MasterPag...er=MP833&Description=Distributor+Pick-Up+Assy

 

[97XJ2]

Thanks, But hopefully the Car Quest one is just fine. I called around the time stores were closing and wanted to make sure I could get one for tomorrow

 

[Spoony]

Ok so the plugs are dry. Injectors not firing then. What would dry plugs have to do with compression? Cam position is the next culprit then.

dry plugs don't have anything to do with compression, sorry. somehow, I erased a huge amount of text, and submitted what you read earlier; my apologies. If you have a node (available at napa, I do believe, you can test the injector signals as it cranks, and see if they're getting "fired". Another way to test (requires buddy system) is to have a buddy crank it over, and you use a mechanic's stethoscope (or my redneck way is a long, thin screwdriver, the business end on the injector, my ear to the end of the handle), and listen for injector clicking.

Has the jeep been driven recently, or has it sat for an extended period of time? I ask, just wondering if the injectors are 'stuck' closed. I've seen this many times on other cars, but only when they've sat, untouched, for many months.

 

[winterbeater]

Have you checked to see that the 12 volts is getting to the injectors? Use a voltmeter from a injector plug to ground to see if they have 12 volts available. If they don't, it has nothing to do with the sensors. The sensors (Crank and Cam position sensors) signal the PCM to complete ground for the injectors. But 12 volts should always be fed to the injectors or else it's a different issue.

 

[Spoony]

wb - does the ecm trigger the inj's with a individual ground signals, and all injectors sharing common 12vdc?

 

[Spoony]

97xj2 - just for future reference, my local autozone stocks the dizzy ignition module. 23$. http://www.autozone.com/R,685645/ve...partType,00034/shopping/partProductDetail.htm

 

[97XJ2]

It had been running daily, until it died, two weeks ago Friday. How expensive is this "node"? Sounds like a good tool to have anyway. I'm poking around their site for it. Thanks for the link to the sensor, we dont have an autozone and our napa and carquest and auto value are pretty sad shops here in the middle of no where.

Edit: I just lost a lot of faith in napa, they sell those tornado things
http://www.napaonline.com/masterpag...765&Description=Tornado+Air+Management+System

 

[winterbeater]

wb - does the ecm trigger the inj's with a individual ground signals, and all injectors sharing common 12vdc?

You got it right!

 

[Spoony]

It had been running daily, until it died, two weeks ago Friday. How expensive is this "node"? Sounds like a good tool to have anyway. I'm poking around their site for it. Thanks for the link to the sensor, we dont have an autozone and our napa and carquest and auto value are pretty sad shops here in the middle of no where.

Edit: I just lost a lot of faith in napa, they sell those tornado things
http://www.napaonline.com/masterpag...765&Description=Tornado+Air+Management+System

LOL @ tornado..

The noid is pretty inexpensive.. i bought a couple a few yrs ago, i think < $10

yes, it's a "noid", not node, like I was calling it.. lol

Here's a cheap set
http://www.toolmancentral.com/Fuel_System_Accessories-c1339-pg4504.htm
There's a ton of them on ebay, too

You got it right!

sweet! thanks for the edjumakashun

 

[97XJ2]

I'll see if Napa has one in stock before I rip into the dizzy.

 

[97XJ2]

Nothing with the cam position sensor, still just cranks and cranks, no sign of any hiccup or it catching. I want to shoot this piece of junk.

 

[89RockHeep]

Nothing with the cam position sensor, still just cranks and cranks, no sign of any hiccup or it catching. I want to shoot this piece of junk.

correct me if im wrong but, Cam position sensor sends signal for which plug to fire correct.Crank position sensor sends the impulse to the injector that supposed to fire, both need to be working properly.CKP sensor (crank) need to read 200+/-75 ohm resistance for it to work properly, you mentioned ordering it, but not installing/recieving it

 

[Spoony]

have you checked the injectors for operation (clicking) yet? I'm thinking it's a fuel delivery issue, since you've been cranking on it, and the plugs are dry...