Engine popping into exhaust

[Tigger]

Hey guys, when I drove the cherokee, I just remembered that it backfires in the exhaust quite a bit, power was really lacking, and I am thinking the timing is off and the carb is WAY ot of adjustment from all the unburned exhaust smell coming into the cab area. So what is the proper timing for a 77 360?

[Tigger]

Oh and it starts like a champ, two taps of the pedal after sitting a week and it fires up. Oil pressure is good (by the factory gauge) and idles fine a bit high but its smooth.

[pyagid]

I want to say the timing should be 8 or 10 btdc on the 360's. Are you sure there are no vaccum leaks or intake leaks?

[jeepsr4ever]

[-X you need to get that engine timed it is essential and you can really damage your motor

[fuzz401]

78 360
auto =6 to 10
manual = 3 to 7

[Tigger]

Yeah I know that is on of the reasons I am not driving it right now. Thanks guys I will most likely work on that this weekend.

[tacoman]

i have a problem similar to this but mine pops through the carb,
i recently changed the timing chain and since the it pops through the carb when going to full throttle from an idle and it has a bit of a miss.
the timing marks are correct. it has a new carb but didnt pop before the timing chain went.
the lifters wont pump up either so i didnt know if that would cause it so could someone please help me, steve

[jeepmonster]

i have a problem similar to this but mine pops through the carb,
i recently changed the timing chain and since the it pops through the carb when going to full throttle from an idle and it has a bit of a miss.
the timing marks are correct. it has a new carb but didnt pop before the timing chain went.
the lifters wont pump up either so i didnt know if that would cause it so could someone please help me, steve

Double check the firing order and that the wires arent crossed, was rotor lined up with #1 cylinder @TDC when you replaced the timing chain?

[tacoman]

man i have checked everything and i did everything the way it should have been done timing wise.
everything is where it is supposed to be, ive done everything but check for compression. ive pulled plug wires off while it runs ect. but i never checked for a vaccuum leak and im going to put a new cap on it.
the lifters like i said will not pump up so when i get it running, correct or not im going to go through the new camshaft break in procedure to see if the pump up and well see if not it is off to the junkyard to get me some heads

[pyagid]

if you re-checked everything, check the compression, it is possible you have a bent push rod or bent valve, and not allowing it to open all the way, also causing the lifter noise.

-paul

[jeepmonster]

man i have checked everything and i did everything the way it should have been done timing wise.
everything is where it is supposed to be, ive done everything but check for compression. ive pulled plug wires off while it runs ect. but i never checked for a vaccuum leak and im going to put a new cap on it.
the lifters like i said will not pump up so when i get it running, correct or not im going to go through the new camshaft break in procedure to see if the pump up and well see if not it is off to the junkyard to get me some heads

Valve springs shot?

[fuzz401]

on my old 360 I had a valve start to pull through the retainer but it was poping through the intake

[Goose]

If youre getting a lot of valvetrain noise as you say the lifters arent pumping up.. take a valve cover off and find out if your getting oil up there if not you have way more trouble than timing also you say the timing chain "WENT" as in it broke? if so I would suspect a bent valve if it was just loose and you changed it probably not.. But investigate the oiling for sure maybe a cam bearing spun or something cutting off oil flow..Good luck

[tacoman]

well i was a dumbass the last time i went wheelin and forgot to put the lid on the oil fill tube and got some water into the motor but the one lifter that was making noise only started when i got to the end of my street and i didnt drive it more than 30 seconds. and when i chenged the oil it went away abruptly.
when i say the timing chain went i mean it literally broke all of the plastic off of 5 consecutive teeth and skipped a few so i dunno how far off it was but im thinking bent valve so if it is the front clip is comming off and it looks like my cherokee is going to be down for a few years lmao.
you know how it is ( since i got it off ill fix this too) lol.
im going to pull the front clip off to take the engine out because ive done an soa and it has 31s on it even though it may not be the tallest i dont have any good trees to work with lol

[tufcj]

Does it pop constantly, or just when coasting or decel? If it still has the AIR system on it, it could be the diverter valve (soup can sized thing behind the distributor) . It has a vacuum connection that shuts off the air from the pump when vacuum is high. If the vacuum switch or the valve is bad, you get enough air into the exhaust system to ignite unburnt gas. It's especially bad if the vehicle runs rich.

Just one more thing to check.

Bob
tufcj

[tacoman]

actually that is one thing i recently thought of because it does, well had an air pump on it but i took the pump off so should i put it back on becaUSE EVERYTHING ELSE IS STILL THERE but i took the pumpoff so do you think that could be it.
it only pops when i got to WOT from an idle or i try to drive it and there is a load on the motor and it appears to be only one cylinder doing it
so i dont think it is a bent valve because i cranked the hell out of it for over an hour trying to start it when it died so im sure i would have bent the whole mess of valves had they hit.