Hi all -

I have a challenging no crank no start condition on my 1996 XJ 6cyl 4.0L. When I turn the key, the lights cut out and I can hear what sounds like a "single crank" but then it stops and I just hear a whirring noise and the lights come back on. The battery is not great but I've also tried starting it with a jump and I've charged the battery up to at least 12.7V and there is no change. At first I thought it was a fuel issue since I had 0psi at the rail so I replaced the fuel pump assembly and now I get normal fuel pressure but it didn't change the no start condition. I've tested the starter by having someone look at the gear while I turn the key; the gear pops out as it should and doesn't retract early. The starter gear doesn't appear damaged and there were no metal shavings in it that would lead me to think it was busted up. I've also cleaned the IAC valve (which caused a crank no start condition about a year ago), cleaned the NSS, and tried swapping the ASD and starter relays with others. No change. There is no CEL and no pending codes. I've also cleaned the battery terminal connections and the connections where wires meet the starter, as well as most grounds. I replaced the spark plugs, wires, and distributor cap about 4 months ago to solve a different no start condition where there was black corrosion inside of the cap that was disrupting the firing sequence.

Important to note is that about a month ago I was able to start the car by pressing down on the gas pedal a lot. This would make the engine rev up really high, but then the jeep would run fine and I could drive it far with no issues and no stalling. I have tried this method recently but it doesn't seem to work anymore. I think this is because I replaced the fuel pump, so before pressing down on the gas pedal would simply maintain pressure at the rail.

I have researched online and have not found any similar posts or descriptions of this issue. Any advice or suggestions are greatly appreciated! I would much rather know what is causing this issue than go straight to buying a new battery and starter.

Thank you for reading,
Kate

 

Let's clarify. You state "no crank", but that the starter drive gear does extend when you attempt to crank it. Does it spin? Does the engine actually turn over? Do you hear the loud "clank" when you try to start it?

Flooring the gas pedal turns off the injectors. It's intended to clear a flooding condition. Have you verified you have spark?

 

Thank you for your response -

I pulled the starter and it functioned normally, it was spinning as it should. The engine does not turn over, and I hear no loud clank when I try to start it. I just went out and tested for spark by grounding one of the spark plugs and having a helper turn the key, and there was no spark at all. Although, I think this is a secondary symptom from the engine not turning over since no signal is being sent for when to fire. I also tried bypassing the relay and NSS by using a piece of wire to connect pins 30 and 87 where the starter relay is in the power distribution center fuse box, which starts the starter but didn't change anything in the behavior of the engine. I think it is that the starter motor retracts as soon as the engine reaches the compression stroke on any cylinder and there is a high load. The starter stays on and the gear is spinning, but it is not engaged with the flexplate anymore.

 

3 options...bad starter...bad ground...bad power cable. If batt cables are original or just old, they are corroded . They were barely good enough when new

 

What Bluejeep said above. When you pulled the starter and hooked it up to a battery, was it a "forceful" spinup (like rip out of your hands spinup)? The clank (or maybe clunk) is the drive gear slamming out as the starter starts top spin.

Have you tried turning over the engine manually with a big wrench/socket? Just verifying the engine is not locked up.

 

I Believe I may have a very possible answer..I had the same issue but I was pulling up and ASD CODE. I did everything I could think of , spending several weeks non stop..I changed everything., and went thru the whole system. Every wire, the fuel system... everything..I gave up and started reading some old hot rod magazines and came up with the answer. 50 / 50 this will work. Go out and pop the hood. Make sure the battery is charged and all fuses good. Unplug the top plug off your alternator..Get inside and turn the key!!
Bosch should of been held responsible for this as their alternator has a habit of shorting inside. It's not a big deal but the power that returns to the system will spike and ****s with the ASD. Since it's not tied to the system directly the ASD tries to assign the issue to the closest thing it can..I figured it wouldn't work for me but damn if it didn't. New alternator the next day. If it doesn't start then alternator is not the issue. Don't get confused either. Running it measured perfect ...

 

thank you all!

I turned over the engine with a wrench and was able to spin it a couple of times so it is not seized. I also inspected the battery cables and some of the wires entering the attachments to the battery terminals are frayed and look to be in bad condition, so I will research replacing these.

negative

postive


I then focused on the engine block ground, the one attached to the ignition coil. I think the previous owner had changed the setup of this ground because there were 3 metal pieces attached on the right stud, and none on the left stud. I took apart this setup and hand-wire brushed a lot of the pieces then reassembled with one ground on each stud. I did notice that the stud closer to the firewall had only the stud nut and no second nut, unlike the other stud which had another nut on top, so I will head to the store to buy a replacement since I saw a picture online of both studs with two nuts. Here is a picture of my current setup after I fixed it.

grounds underneath the ignition coil, I now understand that the grounds need to be in between the two nuts, so I will fix this.

After doing this, I went to try and start the car and when I turned the key it made abnormal ( not the rhythmic ch ch ch ch ) cranking noises for ~3 seconds then roughly started (yay!). I then drove it (no issues at all) for 20 minutes, parked it, turned it off and waited about an hour before trying to start it again. Then, it did not start , and it was in the same condition as before with no crank.

I will definitely look into this and try it---which top plug do you mean? Thank you!