Shortcake1

I'm new here and only my second jeep. I recently bought a 1993 grand Cherokee with 4.0 inline6 and it needed the crankshaft pulley/harmonic balancer replaced. So a mechanic came to my house replaced it now my truck won't turn over which before he worked on it it would start no problem now he says I have no spark. I'm curious how this happened when before he touched it there was no issues like that. Any info would be greatly appreciated. Thanks

PatHenry

There is no direct correlation between a harmonic balancer pulley replacement and a no-spark condition. It's possible that the mechanic inadvertently disconnected something or possibly didn't tighten down the negative battery cable after disconnecting it.
I'd check the tightness on the battery cables and then look around for any disconnected electrical connectors - though I can't think of any that would have been nearby the HB... though I don't know what differences there are with the GC and a regular XJ.

Shortcake1

QUOTE=PatHenry;3526706]There is no direct correlation between a harmonic balancer pulley replacement and a no-spark condition. It's possible that the mechanic inadvertently disconnected something or possibly didn't tighten down the negative battery cable after disconnecting it.
I'd check the tightness on the battery cables and then look around for any disconnected electrical connectors - though I can't think of any that would have been nearby the HB... though I don't know what differences there are with the GC and a regular XJ.[/QUOTE]
won't start
thanks I'll go ahead and look around the starter and alternator since he also changed both idler pulleys could he have messed up the timing some how right before he took off he was pulling certain hoses and having me turn the key again and then went over to coil and did something and said that I was getting no spark but wouldn't tell me where to start trouble shooting really I mean I pretty much do my own work on my cars and trucks and can do just about anything but electrical stuff not so much

jordan96xj

By "wont turn over" do you mean that it cranks but will not start? Or do you mean that you turn the key and the starter does nothing?

Shortcake1

It cranks but won't start I mean it was running the morning the mechanic came over cause I had to back it up some in my driveway for him to have room the only issues electrically I have had is with the stupid alarm which I was gonna disable soon as he was done but I'm gonna go out and look under the hood see if I find any wires loose or connections thanks

PatHenry

I hate to say it, but your whole situation sounds super sketchy. Did your original harmonic balancer (HB) separate? Did the belt break? If it didn't do either, then it's strange that you'd have the mechanic come out to you.

The fact that you have new problems is very odd. The HB is just a pulley - you pull it off with a puller and pop it back on with an installer tool. The idler is even easier, it just bolts on. There's nothing that should have been messed around with electrically. I would look at your CPS connector (look at the back of the intake manifold) - make sure it's connected. Check that your plugs and wires are connected up. Make sure the electrical connector at the back of the coil is plugged in.

I could be wrong, but it's definitely fishy.

If all that seems ok, you can proceed to the standard "Crank no-start" diagnosis steps.

Don't be afraid of the electrical stuff - there's plenty of guidance available and folks that will walk you through things on this forum.

Shortcake1

Thank you so much yes the hb did separate and was wobbling bad just pulled codes on it and it was a 12 and 21 so I'm looking at the wiring right now I would've done the hb myself but didn't have the time and tools for it but the mechanic was short and kept bumping into to wires and kept complaining that this was difficult cause my jeep sits up kinda high has a 3 inch lift on it which is why I'm using a step stool to do anything. Thank you so much again for giving me some ideas of what to check out hopefully it'll be an easy fix I've had it for 2 weeks and only drove it for a week 🙁

jordan96xj

Sometimes things just happen coincidentally. On my first-ever oil change for my wife's brand new minivan, after the job was done, I started the vehicle and a check engine light came on. It absolutely had to be because I bumped something right? But I knew I didn't. But I still tore my hair out figuring I HAD to have done something. Because it was a brand new vehicle with no codes, and threw a code on the very first start after the oil change. IT HAD TO BE SOMETHING I DID. Turned out it was a failed O2 sensor, which was replaced under warranty. Had nothing to do with the oil change. Just coincidence. They happen.

Shortcake1

Oh yes very true I'm actually begining to think it's my fuel pump cause the gauge is always at E and the guy I got it from said its been like that for a long time and had already bought the pump to replace but decided to sell it instead so I got the pump with the purchase of the jeep so I'm gonna look up how to do that and get at it tonight since I know there's very little gas in the tank. So I'm crossing my fingers this works cause I've checked

Atleast 4x all the wiring that I can see coil plugs cps asd fuse anything and everything electrical I could think of and see and it did want to turn over r after I put my foot on the gas a bit it sputtered like it was gonna start but didn't.

jordan96xj

Sputtering and trying to start while feathering the pedal should lead you more towards the IAC (idle air controlller). The fuel pump can be pressure tested to remove the guess work.

Shortcake1

where's the iac on this I'm used to having Ford trucks so I know those motor really well this is only my second jeep first one was the big bad boy grand wagoneer and that motor was different than this one so loved that jeep. Anyways side tracked brain of mine. IAC location

jordan96xj

Idle Air Controller (IAC) is on the back side of the throttle body. Where the large black plastic tube goes into the intake manifold (coming from the air filter box). It is what controls the amount of air entering the combustion chamber when your foot is -off- the gas pedal. When it is not working properly, the most common symptom is stalling at idle or failure to start unless pedal is slightly depressed (which overrides the IAC and lets air into the combustion chamber manually).

Idunno

Poor idle, loping and near-stall RPM began just as XJ (98) warmed up. Symptom has been known for some time but not on the priority list as I went through it to make it roadworthy after a long period of disuse. The vehicle was given to me by a long time acquaintance who was the original owner. Yesterday I finally went under the hood. It started fine but after warm-up began acting up, as I describe it at the beginning of this post, so I started at the intake manifold. It sounded like a bad vacuum leak but all connections and hoses were fine. I then focused on the throttle body and began inspecting things. After some figuring out what did what I removed the IAC. It was filthy. I cleaned it up and polished the conical end with 1000-grit paper. That didn't make any improvement in the idle. While it was running I began unplugging connections to the IAC, TPS and MAS, in that order. No improvements with the IAP unplugged, a slight variation with the TPS unplugged and a face full of flame with the MAS unplugged from a back-fire (so, don't do that) told me the IAC was probably freeloading while the TPS and MAS were probably earning their keep.

I picked up a new IAC and swapped it out this evening. The engine returned to a smooth idle after some (assumed) computer handshaking with the new IAC. I let it warm up and run for 15 minutes (central Florida), shut it down to let it cool and then repeated the check. All seems normal with a tach showing 750 RPM steady. It accelerates smoothly with good response and power and returns to idle immediately, when the throttle is retarded, without any backfiring from poor fuel metering during acceleration and deceleration. Obviously, the original IAC had gone hooves-up.

The original owner parked it for this reason but couldn't diagnose the cause. In the interim (8 months) he unknowingly left a window open, rain entered the truck and, long story short, the floorboards rusted through and the interior went to mold. After he got the spirit up to tackle the idle problem again he discovered the open window and rotting interior. He stripped it out thinking a quick fix was in the cards, saw the amount of work ahead of him and bought another truck instead.

I refinished the exterior (gun metal pearl), repaired it structurally, installed new or repaired interior items and as of yesterday went at the drive train. As soon as it's roadworthy (minor details remaining) it goes to my youngest son (20) as his first vehicle. I drive a 96 XJ that has been a great and reliable runner save for a crankshaft position sensor that failed last Spring and gave me the opportunity to take a leisurely 4 mile walk home.

Shortcake1

I got it to turn over today after putting the battery on a trickle charge over night I've ran it for 10 mins then turned off then again through out the day turned over every time without any hesitation but it has some sputtering not like it's gonna die but like its not getting enough gas so looks like I'm doing a fuel pump swap tomorrow morning which it needs anyways so thank you for all the help from everyone and I also have a new iac ordered coming Friday