YJ turning over but not starting. New fuel pump, sending unit, filter, rubber hoses

[Jtlinn]

95 AT Jeep YJ 4.0 She ran great until September when gas started leaking out of one of the hoses under the drivers side rear. I drove it 2 more short trips until it really started coming out. It eventually stalled and I decided since that hose was apparently rotten and I needed to drop the tank anyway that I would go ahead and change the fuel pump, sending unit, rubber hoses, and fuel filter and those little hoses. I also installed a new tire carrier bumper since the fuel tank was out. Ive been working on this thing solo now in my spare time since Sept. 17 and yet to get her back on the road.

From what I can tell, I have the hoses hooked back up (I think properly), I couldn't squeeze that rubber grommet back in under the underbody so I used a plastic hose/wire protector. I tried to fire her up and it just spins.

Verified that the Battery is good, I hear the pump come on, there is fuel in the rail. I put in 5 gallons of fuel and it registers on the gauge, even though I don't have the tank fully bolted back in (I was attempting to test it). I swapped the relays out and they seem good as do the fuses. I do not see any movement on the tackometer when I try to start it (not sure if im supposed to). I also sprayed some starter fluid down the intake with no luck. The check engine lights seem to operate as normal.

I think I may have an underlying ground issue somewhere as the heater blower fan is not working either. It went out when I first bought it but since it was summer I didn't really worry with it. That's next after I get this girl rolling again.

Uncertain where I go from here...Thanks in advance for all the advise and direction I surely need it

 

[superj]

the tach should move while cranking but if you sprayed fluid into the intake and no luck, you are not getting spark. fix that one first.

 

[Jtlinn]

the tach should move while cranking but if you sprayed fluid into the intake and no luck, you are not getting spark. fix that one first.

Actually I don't think I sprayed it directly down the throttle body, my mistake. I was reading another thread and Im not positive I got it down in there enough, but thank you so much. I will start there! What did you mean by the YJ? Have they given you a good share of problems? I just want to get mine back on the road. Thanks in advance for the guidance! Ill report back the results!

 

[JPNinPA]

So the engine turns but does not start.

And codes or CEL (check engine light)

Check the fuel pressure at the rail to make sure you have sufficient pressure.
Verify you have air. And no restriction. Unlikely but this could be as east as testing with the air tube disconnected from the TB
Spark, check your plugs and verify all spark.

Too much air could do the same as not enough. Being the fuel line was broke be sure it's not leaking anymore and there is enough fuel to prime the lines.

 

[Jtlinn]

So the engine turns but does not start.

And codes or CEL (check engine light)

Check the fuel pressure at the rail to make sure you have sufficient pressure.
Verify you have air. And no restriction. Unlikely but this could be as east as testing with the air tube disconnected from the TB
Spark, check your plugs and verify all spark.

Too much air could do the same as not enough. Being the fuel line was broke be sure it's not leaking anymore and there is enough fuel to prime the lines.

So I tested the fuel pressure and it was in between 39 and 41. Then I started checking for spark. I tried two plugs with a spark tester and no light and no start. I also tried the starter fluid again just for safe measure and no go.

At at this point I am guessing it could be the plugs, plug wires, maybe distributor, or relay? What do ya think?

 

[superj]

check the cap and rotor, first. just unhook the cap from the top of the distributor and lift it off. inside that cap is a bunch of little contacts that will be burned looking. you can get a cap very cheap at your local auto parts place and swap the wires from the old cap to the new cap, one at a time so you get them in the same spot. then, under the cap but still on the distributor is a little thing that pulls straight up, off the distributor. that is the rotor. swap it with a new one, also. those two parts are cheap enough to justt change them straight out and they should be changed anyway.

now, you can do wires ad plugs if you want.



I have sold my yj. I liked it but it wasn't really useful for me because I cycle. I needed something with larger bed

 

[69jeepcj]

Crank position sensor?? does the yj have a ignition module like the cj's had?

 

[Jtlinn]

check the cap and rotor, first. just unhook the cap from the top of the distributor and lift it off. inside that cap is a bunch of little contacts that will be burned looking. you can get a cap very cheap at your local auto parts place and swap the wires from the old cap to the new cap, one at a time so you get them in the same spot. then, under the cap but still on the distributor is a little thing that pulls straight up, off the distributor. that is the rotor. swap it with a new one, also. those two parts are cheap enough to justt change them straight out and they should be changed anyway.

now, you can do wires ad plugs if you want.



I have sold my yj. I liked it but it wasn't really useful for me because I cycle. I needed something with larger bed

Than you Sir! The distributor, plugs, and wires are less than a year old and Ive only driven it maybe 2500 miles, just a fun knockaround. I did however check the spark between the coil and distributor cap and there was no spark there either. Could this be a bad coil? Maybe an ASD relay issue? Or maybe that crank position sensor as another member advised? I appreciate all the help from everyone! Thanks again!

 

[acockrell]

I have a 1994 YJ Sport ... I worked on my transfer case and my jeep acted the same exact way but seemed to be fine before i worked under the jeep...it was the CRANK CASE POSITION SENSOR!! I tested mine with a multimeter and it tested okay...I decided to replace it anyway with a new one and it cranked right up. And with that replaced my Jeep runs better, doesnt smell like it has a gas leak and cranks the first time everytime.

Just my two cents!

 

[greg92jeepxj]

I have a 1994 YJ Sport ... I worked on my transfer case and my jeep acted the same exact way but seemed to be fine before i worked under the jeep...it was the CRANK CASE POSITION SENSOR!! I tested mine with a multimeter and it tested okay...I decided to replace it anyway with a new one and it cranked right up. And with that replaced my Jeep runs better, doesnt smell like it has a gas leak and cranks the first time everytime.

Just my two cents!

thank you for your post brother .
yes , there is credence to this as live date from scan and labscope have determined that oxygen sensors and cam and crankshaft sensors often cause drivability , stalling and no start issues because the sensors are OUT OF RANGE. We are fooled into believing the sensor is good because the multimeter say good but it takes a more accurate means to determine the actual health of the sensor. Cam and crank sensors have magnets which rely on good magnetism to achieve good readings. Don't know if magnets wear but debris can interfere with accuracy. Be that as it may , it gets expensive to have diagnostic sessions to find the problem which is why folks resort to parts changing to go cheap and avoid the diagnostic fee AND the part fee . It's always a tough call. I put my trust in dealer parts if can be gotten . Outrageous cost , we know . But flaky , inferior parts just add to the headaches . Known good used parts from the wrecking yards got a better chance sometimes than junk from the chain stores or mom and pop store too because they all come from the same vendor. But it is worth noting your fix and well worth the consideration .
We are told " don't be a parts changer " but we need to be better at diagnosing .
who's got a scan tool and luxury items such as a labscope ? There won't be one under my Christmas tree this year .

 

[greg92jeepxj]

I have a 1994 YJ Sport ... I worked on my transfer case and my jeep acted the same exact way but seemed to be fine before i worked under the jeep...it was the CRANK CASE POSITION SENSOR!! I tested mine with a multimeter and it tested okay...I decided to replace it anyway with a new one and it cranked right up. And with that replaced my Jeep runs better, doesnt smell like it has a gas leak and cranks the first time everytime.

Just my two cents!

Read your post a second time and a little confused over the part / sensor name.
you posted you were working on the t-case but said the offending part was the CRANK CASE POSITION SENSOR ?
Ok , to clarify I'm not misunderstanding for the benefit of the OP .
The crankshaft position sensor ( CKP ) is on the bell housing on a 4.0 liter I6 .
on a t-case there may be a VSS ( vehicle speed sensor ) if equipped that model year .
just wanted to clarify but not looking to add confusion to thread either . Sorry for the misunderstanding.

 

[superj]

check the bell housing sensor, as spoken of above.

 

[Jtlinn]

I apologize for being away gang...my daughters activities took me away from troubleshooting this YJ! It dawned on me the last time it hit the pavement was September 17th and I'm really trying to get her running before Christmas Eve so I can take my nieces and daughter for a chilly NC ride, so I need your continued help and direction, PLEASE!!

So I "tested" for a vacuum and didn't feel much. Now I don't have a vacuum tester, but I did see that I should probably replace one of the hoses that goes to the fuel rail as it looks pretty crispy. Of course this isn't why she's not starting, but something for later.

I put a voltmeter on the Camshaft Crank Sensor and I show the approximate amount of voltage. I really hoped that this was it but apparently it seems good.

I "attempted" to test the auto shutdown relay holder/box (not sure what this is called) and really would appreciate specific instructions on how to complete this test. Please help. I did swap the relays around for example I took the one off the ASR and put it in the horn slot and it worked. I heard this device can rot out or something.

Testing for spark. I went back and tried this again. I can confirm that there is no spark at the plugs or distributor. I also tried the coil and NO SPARK. I tested the voltage on the back of the coil and it is getting power. I am leaning towards possibly a bad coil. If this is the case, is there a brand better than another...or where would you purchase one? It appears to be an easy install.

Finally gang, this thing was running like a champ before I had to park it with that rubber hose fuel leak. Again everything related to that appears fine.

I cant thank you guys enough for your help and guidance. I'm handy and love working on the Jeep but definitely not a mechanic. Thanks again!

 

[superj]

The sensor in the transmission was good? Those are very common items to go out, that cps.

 

[Jtlinn]

Yes Sir! It had the recommended voltage. I imagine I could replace it and see if hat does the job. Thoughts? THANK YOU!

 

[superj]

Let me think. I normally just replace them so let me check my manual on the sensor and ser what everyone else says

 

[JPNinPA]

When changing sensors in a jeep, use only OEM sensors. The others appear to fail right out of the box.
Specifically the CKP needs to have the thin paper gasket on the surface when installing. This acts like a spacer and keeps the flywheel from cracking the sensor housing..


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[greg92jeepxj]

You may If you want to check the auto shutdown relay , just swap a known good relay in its place . The a/c relay will do . If you wanted to bypass , jump terminal 30 to terminal 87. But use a good relay to maintain connectivity. Although the last check of the crank sensor revealed good , keep an open mind . Remember , there is ground , signal ( 5volt reference ) and the return . The return is what calls the shots. I certainly hope the test equipment being used is computer safe ? You've posted that the coil input read voltage but no output. You can try to clean any corrosion , especially where it mounts to the engine block . First clean a spot on the block and clean an exposed place on the coil that is not epoxy coated . See if you get continuity which would mean you've got ground . Clean corrosion the best you can anyway since a multimeter reading is only so suffice compared to a coils need . Before taking the dive to replace parts , do the best diagnostics you can . Dealer parts are expensive ( but worth it ) and aftermarket are usually a risk . More sensor readings can be taken to verify if PCM has good feedback to all sensors , not just the CKP. A cam sensor should be checked on a no start too. Don't want you to get swap happy , just diagnose . The coil reading is an interesting find .

 

[Jtlinn]

I am so grateful for all the feedback! Thank you all again!
Seems like the consensus is that it could be a couple ofthings regardless of the diagnostics. Iam of course no expert at figuring all of this out, however if I can save acouple of bucks I definitely prefer to do that. Thanks again for the guidance. Ido not have the original repair manual for 95 YJ 4.0 Auto.
Depending on the outcome, finding OEM Mopar parts seems abit challenging. I don’t have a localjunkyard accessible; however I can order parts online and have done so in thepast with the vendors that sell all kinds of stuff other than the parts thatyou really need. I have the 4 big partsstores in the area, but nowhere jeep specific. Any recommendations would be appreciated.
I can pretty much guess getting this thing back on the roadis going to take one or more of the following:

1. Several more diagnostic tests
   
2. Changing the Crankcase position sensor (withgasket)
   
3. Changing ignition coil
   
4. Potential PCM issue/Auto Shutdown Relay?

I did swap some relays around like the horn for the ASR andthe horn worked.
At any rate, again I appreciate the guidance and shepherdingthrough this!!

 

[JPNinPA]

Rockauto.com for your parts. They highlight what parts are OEM and also highlight parts that performed the best.


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