Jamie Thompson

1998 Jeep Cherokee Classic 4.0 inline 6cyl.

I just swapped out transmission with one from a junk yard. With advice, I used the TQ that came with the tranny. I used the same crankshaft position sensor and plugged everything back in.

I started the jeep for the first time after the swap and it started jut like it usually did with no hesitation (being on a charger)
I shut the jeep off then tried to start it again now I have no spark, no start.

Fuses are all good but gauges went haywire and flicker a little, but now they dont move. All lights in dash work, gauges flicker or dont work.

engine has no spark now all of a sudden. No prime to fuel pump and gauges are being weird..

WtF is the issue here?. Why would it start one second, then have no spark the next second time?
I'm by myself and I can't really test much with me cranking and watching the meter.

Also I installed the sensor with out the black spacer thing in bellhousing originally. Maybe CPS now?

Cane

out of curiosity, the tranny came from what year jeep?

Willys55

recheck your battery connections and grounds, oh and make sure you didn't pinch any wires between the block and transmission.

Jamie Thompson

Battery connections should have nothing to do with spark. No wires pinched all connections are tight..

im assuming trans came from a 98 im not 100%. Its exact same type though.

fb97xj1

That black thing is just a dust cover to keep dirt off the sensor. Did you remove the crank sensor for the install? If not, it may have been bumped during the install, possibly damaging it. The only major difference with transmissions that i know of are the addition of a second speed sensor on the 98-01 AW4. The 97 and older AW4 had only one. Make sure everything has been reconnected. Retrace your steps. Even the pros miss stuff every now and then. Like drain plugs.

Checking the battery cables is a good idea. The fuel pump doesnt prime, correct? It is not getting power for some reason. You checked fuses. What about the ASD relay?

Jamie Thompson

I triple checked all the fuses
and im getting power to it. I don't know if its leaving it. I have 2 sensors on tranny so 98 im assuming? The sensor I had out while installing tranny. So f'ing frustrated right now with this damn jeep..

Rogue4x4

Connections have nothing to do with spark? Seriously?

Doc's advice is solid. Double check all your work. If you rushed through it as bad as you rush through writing these posts, it probably needs it.

freegdr

Battery connection have everthing to do with spark and ever electrical function.

BlueRidgeMark

Yep, what they said. I know you're frustrated right now, and when we're frustrated we don't think clearly. What these guys said is true for every vehicle on the road, and especially true for our Jeeps. The PCM is very sensitive to the battery connections, especially the grounds. Strange things can happen when its not happy, and since the PCM makes the spark....




How did you check it? With a meter? If so, try again with a test light. Also, physically check each connection, and get rough with them. Pull, push, wiggle, and shake. You are trying to find the bad connection.

Here's the deal: When there is a poor connection, you can measure full voltage with a meter, but once there is a load on the circuit, the voltage drops, often to near zero. A meter doesn't load a circuit, so you can measure good voltage, but as soon as you try to run something, bang, you have no juice.

A poor connection can be from something being loose, or just corrosion at a connection or in a wire.

I'm betting you are going to find a bad connection or two, not a transmission problem.

Jamie Thompson

The fuse box under my hood with the ASD and fuel relay. It has 2 rows of miniature fuses. Are them miniature fuses all supposse to have power coming into them? My last 2 a 15 and 20 do not hve power to them
I can take a pic if needed.

I cleaned ground strap at firewall, 2 under ignition coil one on my engine block nd one beside battery to body
I tripled checked the fuses, connectors, wire harness 15 times. Everything is peachy..

okay lets say I have a **** battery that doesnt hold charge. I hook it up to my cranking charger the engine cranks fine all lights work untll I unhook charger. Could that be a problem? I mean if its cranking it should start no matter how my battery or connections are right?
should I try a good battery becuse I have a gpod spare one. I just doubt this will change anything seeing tht it crnks.

I didnt pinch anywires and I actually took my time.
I installed tranny my self was not easy however everything is put back the way it went.

I am leaning to my Crank sensor in bellhousing. Seeing that this will cause my no spark no fuel prime, but however I am leaning away from it from seeing my gauges go haywire then dont work..

omg I dont have the money to just replace parts untill I get it running..

I tested my ASD with test light. Top prong has power no where else key off.

Under hood in fuse bus I have Miniature fuses. 2 rows. The row towards my asd relay I do not have power to 2 of them fuses.the last 2.Its a 15 and a 20. Key on or off.. idk if that is normal.

BlueRidgeMark

Wait... Are you saying that everything works fine when you have it hooked up to a charger that provides enough juice to crank it?

If so, replace the battery. Stop making this complicated.

Jamie Thompson

okay, Listen im here for a no spark issue.. Not that complicated...
I have plenty of cranking power no mtter where its coming from battery, chrger, hell even another jeep... Seeing that im asking about no spark issue nd not a Ahh dead god damn battery issue we can rule out the battery. ?


So back to issue at hand..
under hood in fuse bus I have Miniature fuses. There are 2 rows actually. Should I have power to all them fuses key off or on
Position? There are 2 a 15 and 20 tht I dont have juice coming to.. could be a culprit if this is not normal?

Martlor13

fb97xj1

Start with a new battery. Or a spare you know for certain is good. Troubleshooting is a pain, but it must be done. No matter how frustrating.

Jamie Thompson

Ok, new battery full charge. Brnd new connectors for battery. Snipped wire back also.

same results although im cranking alot faster..
im lost on testkng for volts and ****. But im getting 12.8v o. All fuses.

if I tke my test light and hook it up to +on battery and take and touch a prong or 2 at my connector at my brain box I can get fuel pump to kick on and relay to click...

**** sakes ny one close to hughesville willing to take a look.. super annoyed trying all this myself..

yes crank sensor spells my no spark and fuel pump prime issue but wtf is going on with my gauges now.. RAAAAWWWRRRRRR... DMN