92 xj laredo timing? or?

[uberxj92]

1992 xj laredo, 4.0, aw4,4x4,dana 30 hd & ford8.8.
about 2 weeks ago the ignition started acting up with the occasional super fast "cut out" or "hiccup" at lower rpm's. changed the ignition electrical switch under dash on steering column.
ran fine for a day, then very hard to start. she would just turn over like 20 or 30 times then catch & go. later that day she wouldnt start.
next day after she was cooled off very hard to start again but, when she did start she started like an old diesel with the real low rpm ( rough too) then all of a sudden the computer made an adjustment & up to 1500 rpm she went smooth as silk for about 2 hours. cleaned the battery cables & connections on the alt & the cleaned out the distributor ( which was shiny ).
now while driving she has really rough times & some smooth times & some times she backfires thru the snorkel.

local 4x4 guru just went under last week ( i think thats why my girl is acting up), but h has 2 comps & is bringing them by today for me to try.

i did the self test on the jeep yesterday ( turn the ignition on & off & on & off & on). here are the codes:
12-Battery or power to the ECM disconnected in the last 50 key cycles.
75-? cant find a 75 anywhere but, just to be thorough i check 76 which is-Fuel pump bypass relay circuit. bypassed that & tried a new one no change
35- Cooling fan relay. no biggy i have the taurus fan & stock fan wired on separate circuits.
15-Speed sensor or circuit. the jeep has the electric speedo which quit working along with the cruise 4 years ago & i had to unplug it cause it was setting off the rev limiter at 30 mph lol.

yes this jeep has been used very well on & off road in the ocala national forest here in florida.
i am going to try the comp today & then test the fuel pressure & tps. maybe if i have the cash on the card i will swap the cps too.
let me know what you guys think. cause the jeep dealership ( 5 star at that) here in town told me to wreck it or set it ablaze & collect the insurance & come in & by a real jeep. not happening

[4.3LXJ]

Probably the cps. Sounds just like it.

[uberxj92]

update: after chiseling my way to the fuel filter & fuel pump...filter replaced it was bad but not enough to kill it. fuel pump at 28psi at the rail.
ordered pump & cps for tomorrow.

tried new ecu today & it ran a little better but not much then it went back to crap.

still flashing 73 & 75. if anyone knows what those are let me know lol .

[4.3LXJ]

Can't find those. but 72 is cat and 76 us fuel pump bypass relay cirduit.

[uberxj92]

update....dropped fuel cell. cleaned it out with mineral spirits & steam. replacing sock & probably the pump too.
i got it running but the fuel pressure is screwy.
bypassed & replaced the fuel pump resistor on the driver's fender underhood.

on a softer note i do believe i know what happened: i pulled out 2 fords the day this happened & i think that she might have gotten an upset stomach from too much ford. LOL LOL just kidding.

[uberxj92]

i finally was able to get to finishing the repair.

turns out that the rubber hose on the fuel pump inside the tank had vibrated loose and since these fuel systems arent volume pumps but pressure instead....there it was.

tightened that hose & cleaned out the tank while i was at it & changed out the sock.

runs like a raped ape now.