Jeep grand cherokee backfire at 1500rpm

4.0l i6 hard start idles fine, backfires through intake at 1500. Crank, tps, iac, map sensors are fine. Coil plugs and wires changed. Cap and rotor fine. No exhaust blockage. Fuel pressure fine. Voltage fine. No vacuum leaks.
I reset the timing to tdc and im 6 degrees advanced. Its pinned so i think i need to replace the chain and sprockets.
Any advice is welcome. Please be kind and mature in comments.

[@drewflesia]

yes. it was the distributor. it got slightly warped. just enough to start but go out of time at driving rpms.

[@angelf9800]

andrew flesia how Does it happen. I am having the same problem I replaced the cam the Crank and still backfires and sometimes it will not start and other days it will 🤔

[@ThIzZi31]

@@angelf9800 did you ever figure it out? I'm have similar issues

[@jasonboyce2250]

I've been told threw a gd friend cause I'm having the same issue that it's a small crack in the header pipe and could be sucking more air to fuel. Gonna try and get it wielded.

[@sylviagar91]

have u fix the problem if so plz let me no I'm having the same problems I heard recently it could be the Cadillac converter that stops your full pressure going out the mufflers back fires into the intake manifold or a bad valve

[@91drunkenmonkey]

Your 5 year old is now a 10 year old 👍🏼

[@ahrifox8568]

Now a teen.

[@zaq55555555555555555]

I definitely think your timing set is bad. Ive been helping a friend with renix problems and that was definitely one of them.

[@drewflesia]

mine ended up being a slightly warped distributor casing. have you tried the old paper on the tailepipe trick. backfire out the tail could be a burned exhaust valve

[@LuisContreras-gd4lc]

can you please tell me this trick?

[@LuisContreras-gd4lc]

i have invested so much in my jeep and still doing back fire. fuel pum, pcv valve, crankshaft sensor etc. but dont know what to do

[@jacobsanfacon458]

Figure it out ???

[@austinphillips3148]

I’m having the same problem but a rough idle also

[@ThIzZi31]

Did you ever figure it out? I'm having the same problem.

[@keegannickel5752]

My Jeep Grand Cherokee was running fine and I changed the distrubitor cap an spark plugs and wires then started it and it was sputtering backfiring at 1500rpms. Still haven’t figured it out let me know if you know anything about it.

[@ThIzZi31]

Have you figured it out? I'm having the same issue

[@keegannickel5752]

It also shook really bad and I know I didn’t turn the rowder. So I don’t think timing is off

[@tristanr42]

I am having the same exact problem , does anyone have any idea as to what the problem is ??

[@danastle2848]

vaccum leak at idle air control causing a lean mix thats being corrected by the 02 sensors and its over compensating

[@danastle2848]

notice how it starts fine at first and then it runs as if the choke is still on if it had a choke , skips runs rich and smokes

[@danastle2848]

the idle air control ,vaccum housing is supposed to open the throttle a small amount at startup and you can do this manually as well with the gas pedal but the popping is caused by the unmetered air

[@danastle2848]

the idle air control module vaccum actuators can leak as much as the tubes can dryrot, you can check these by sucking air out of the tube with your mouth if you dont have a vaccum pump , they should be sealed with no holes or its bad , you can block off the vaccum tube and still drive the car

[@abeezydadon4413]

Try the crankshaft sensor

[@jeremysparks205]

My battery died and this problem came up and mine backfires through the intake and I have a 91 Cherokee and I’m kinda lost too I just don’t know what to do eather

[@juanpichardo303]

How did you solved it?

[@joeyfridline8333]

check your distributors. my middle plug had a science experiment on it and the cord was cut in half

[@Onecooliceman]

What was the problem

[@danielholsemback5515]

What was the solution? My wrangler 4cylinder is doing the exact same thing.

[@daytonjustis569]

Change the fuel pressure regulator

[@davidmorris8803]

Sounds like it's got a stuck valve

[@sabstang6567]

Same problem on freshly built motor. Did you ever solve problem. Thanks

[@calebcoats8340]

Having this issue any info on repair yet

[@jonathanharvey8851]

I changed everything you did mine was also the distributor

[@joelsmith7896]

My 98 Cherokee does the exact same thing after I replaced the camshaft I have checked and rechecked the cam timing. What exactly was wrong with your distributor that caused this problem.

[@IMP429]

Did you find out what it was?

[@lesliegibson477]

Did u find out what it was

[@lebiismaelbonilla4565]

Probably is the crankshaft sensor

[@brianhalstead5706]

I have exact same issue on 2000 jeep Cherokee xj 4.0 it takes 3 attempts to start and it sounds like it's backfiring from intake as well. I do have check engine light the code is P0171 and I was told at auto store it's upstream O2 sensor so I replaced it then I did the MAP/MAF since both in one and I also changed the crankshaft cap sensor and I'm still having issue I removed catalytic converter. Too .. what has helped us I unplugged both O2 sensors ran it at idle for 10 min it began to run really bad then I shut it off plugged both back in and after 10 min of idle it ran good in fact problem solved but the next day problem is coming back I can tell it's not fixed so what's the issue ? I backfires under hood when I lift off gas then press back on it with a load or going up hill and when I take off it goes good at first then it seems to run like it just needs to be floored to blow out whatever is restricting it.

[@danielleduncan13]

I have the same problem did you replace your distributor because I was told to replace my distributor or spark plugs I haven't yet but we have the same exact jeep and I've been through 3 mufflers cause they busted so my question do you think after I get a new distributor and muffler I'll be running fine?

[@mattanderson8436]

Did you ever get this solved?

[@gustavosandoval8000]

Did you happend to have any codes?

[@joeyboling7392]

Same problem

[@joshkohler1910]

I'm having the some thing right now

[@JoseRodriguez-ok7mx]

Yess hello can i get ahold of u by phone any time soon

[@itsjustprofessionalidiots4398]

I’m having same problem how did you fix it