jeepguy4life

just got a 93 jeep cherokee sport 4x4 with 4.0 auto w/125000 miles
it starts up and runs ok till i put in gear and start to drive and it spits and sputters also back fires and dies . will start back up and set and idle.
has new wires, plugs, cap, roator, coil ,distributor, fuel pump, crank position sensor, throttle position sensor, computer ,converter gutted .
any help with this would be apprieated.

DFlintstone

Besides checking the fuel pressure, I might conciser exhaust restriction from the CAT, (or a potato in the tail-pipe), (really, look). In the link in my signature, Crusier has an easy vacuum test for a plogged exhaust.

Also believe it or not, yours is suppose to display codes:


The "Key Tricks"
Older (OBDI) models - Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. ("On" is NOT "Start" and "Off" is NOT "Lock"). The "check engine" light will flash. Count the flashes. Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH FLASH (long pause). It will never flash more than 9 times, so watch for those pauses!

partsguyct

Just to elaborate when it flashes it will be long flashes referencing ten and short for one. Not trying to one up you or anything just trying to help more for those that aren't used to that style computer system.

DFlintstone

No! Not at all, glad for the feedback. Has yours been useful?

partsguyct

Has what been useful? My computer doesn't send codes so its quite useless even when there is a problem lol

DFlintstone

Does the light work?

partsguyct

Yeah it turns on with key on engine off but it doesn't seem to get hard codes, I had to find someone with an obd1 reader when I was having starting issues to find out my cam sensor was shot. Might just spend the money for a reader from work for the future, I hate having to borrow stuff like that.

DFlintstone

Hey, thanks. I was just curious, Mine's Renix. Anyway I guess allot of parts places will do it free.

jeepguy4life

got a little time today to mess with jeep and pulled fuel line and coil wire and cranked it over several times and shot fuel for a few seconds and then to a real low flow . it does not seem to be pumping the fuel to keep it running under a load . do not have pressure gauge at this time to check fuel pressure. the old owner put in new delphi fuel pump and i am wondering if may be he pinched or twisted a vent line .he said he had a hard time with pump install.and it ran ok before install he replaced pump because old pump was noisey. i am planning to pull pump and tank just to see. if i can find something wrong there. when i do i will just return old pump and get another new one still under warranty.will check lines for clogged lines and ect.. the converter is gutted and i got the exhaust apart before muffler.

DFlintstone

There's others who know your 94 better that me.

Don't you have the ceramic ballast resistor by the air cleaner? The rear of that should have at least 8-9 volts, or bypassing it and running 12 right to the pump is OK. Your reference to "gutting" might violate forum rules, I might edit that out. You do know you don't need to pull a line for fuel pressure. There is a Schrader valve, like a tire valve right on the rail.

I'd verify there is no pressure when the pump has power and ground, before I pulled the tank.

jeepguy4life

hey guys thanks for the help got 93 jeep fixed. it was the fuel pump nice of the parts store to give some one the wrong pump . but it seams like they only know what the computer tells them and do not know how to cross reference anything .somtimes sure do miss the old way of doing things. well on the bright side i did not put pump in the first time so only had to do it once and sure glad i decided to drop tank to do so. all in all turned out good just took time.