NMJeep01

Okay, so let me start off with what i have, 97 jeep cherokee 4.0, 5 speed, So let me start with the progression that has ended up to where i am at now, so the jeep was running great for a while up until one day when i went mudding for a bit the jeep just dies on me took me a while to figure it out thought i may have had water in distributor and ended up finding out that it was the cps (Crankshaft Position Sensor) one of the bolts had fell off and the sensor was hanging there ended up getting a new CPS from autozone and it fixed the no startup for a while, although while this sensor was working i would have sudden jerks going down the road at any speed this would happen as if rpm's went down all the way and suddenly jumped back up to normal this is when i began to think that possibly my distributor was bad so i went on to buy a new distributor new spark plugs new spark plug wires, the problem was still there with the jerking, so i went on to buy brand new 6 injectors and the problem was still there, i left it for a while because of lack of money and not thinking that the problem was too bad, then one morning i started the jeep up and there was terrible idling so i changed the IAC (Idle Air Control) and it fixed the rough idle although the the jerking problem still was there, couldnt figure out the jerk so i still left it for a while untill it has progressively gotten worse, it was recently back firing horridly from the intake and the exhaust thought that timing was possibly off ive timed it over 10 times now with no fix (im at a high elevation by the way) so i began to look back at the CPS and read up on it and saw that the autozone sensors were crap so i went out and bought a MOPAR one hoping it would solve all of the issues, although the issue still prevailed so i ended up thinking that maybe the timing chain could be the cause so i went out and bought a new timing chain installed it and re timed everything this time with the valve cover off to be positive of the TDC and also to check all of my valves and what not because of the backfiring, all valves and everything checked out good, so i retimed everything including a new timing chain, and now the jeep wont start, i am at a hilt and am very confused on what it could be ive been reading and there are very few things left that i think it could be maybe the MAP, Fuel pump? 02 sensor/ wires maybe its a month old sensor so maybe the wires? any help would be greatly appreciated i am at a holt any advice will help a lot. oh also the back firing sometimes would not start to happen instantly unless i gunned it then it would happen instantly, and i would almost be able to avoid the backfiring if i kept rpms under 2000 again any help would be appreciated

freegdr

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JackJare9455

jeez you have thrown alot of parts at this issue...

the problem is kind of all over the place...

there are 3 things needed for a gas engine to run...considering timing is dead on... spark.. fuel..and compression

all of this seemed to start from the time you went mudding.. but kinda of spiraled out of control... so as of right now.. lets start at where you are at right now.. cranks but no start...

any codes present??

are you getting spark when cranking?

are you getting fuel pressure? is the fuel pump even priming?

pull plugs.. are they wet??

are the injectors pulsing? (noid light)

if you are getting spark... will the jeep crank with an outside fuel source like starting fluid?

fuses all good? relays?

when you timed the engine.. i assume you timed it at TDC on the compression stroke?

everything was plugged back in??

i have seen clogged fuel filters cause an engine to studder like you previously mentioned.. plugging up.. building pressure.. and releasing fuel..

start easy here... troubleshoot the problem.. dont throw parts at it...

NMJeep01

are you talking about timing chain? if so i lined both marks up properly on timing chain, with distributor had pointing at number one and had the engine at tdc, at this point im still looking at the CPS, i lost both of the original bolts and cant find spec for them anywhere not even at the dealer ship im thinking that the bolt is just a little bit narrower causing the distance Between the CPS and the flywheel to be off just enough, although i have tried to fimble around with it and adjust it and still nothing, it just cranks and cranks without any start

JackJare9455

NMJeep01

there were some codes but the timing chain seemed to of cleared them, i get spark, i plugged everything back in, the last thing i need to check for is fuel pressure (haven't had a gauge) im going to check that tomorrow. im hoping is just a fuel pump, although the fuel pump just doesnt seem to make sense to me because the pump was working perfect before i pulled timing chain, oh and one important thing i forgot to say i dont know why i forgot but it has started up one time when cranking after all of this, although that was only for a couple of seconds and it happened to of start when we were messing with the cps.

freegdr

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freegdr

It started b4 chain install proper installation needs to be confirmed first off....

freegdr

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NMJeep01

it started once after chain install but only for a brief time, this happend when we were moving around the CPS

JackJare9455

i was fixing to repost and say to work in reverse order... it stopped cranking after you messed with the distributor/timing.. so that would need to be addressed first..

hell i was even going to say to check and make sure you had fuel!! wouldnt say it if i didnt see it before...

but now it has cranked since you messed with the cps? i would warranty out that cps.. check the connector.. and see if it will run..

if you have spark.. then adding an alternative fuel source through the throttle body SHOULD fire off if the timing is set correctly...

you should hear the fuel pump whine when turning the key over to accessory (position right before start)

NMJeep01

this is my third CPS because it always seems to lead back to it, im thinking its because of the bolts holding it? any thoughts on that? also do you know where i could get spec information for those bolts? and thanks for all of your input i appreciate it!

NMJeep01

i have done the fuel through throttle body and it coughed a little but no start

JackJare9455

is the socket head metric??

i was doing some googling... M6x1.0 and M7x1.0 popped up on a few forums..

i do believe an 11mm hex head bolt mates to a M6 shank

freegdr

Sooner or later you get lucky and replace the correct part and get your issue fixed.