91familyxj

Ok so here we go. I have a 1991 larado and I was driving today and everything was fine untill it started almost like sputtering. My rpm's will drop like the truck it dieing and starting again. My temp is fine my oil pres is fine evrything seems to be fine. So I pulled over and waited a little the srated driving and a cuople minutes later bamb it does it again so I do it all over pull over then start driving and does it again all the way home. So does anyone have an idea what it could be?

AWOL

fuel pump going out is a possibility. when you pull over and sit a min you have the fuel pressure to idle fine but when you start driving and need the fuel you dont have it and it starts to sputter and die. Or fuel pressure regulator.

91familyxj

no its the worst at idle. I have a brand new fuel pump. So when Im driving if I hold my brake and stay on the gas it drives not perfect but drives. so at the red lights I have to put it in nutral and keep it at like 3000 rpms

Abovetimberline

There is a number of things it can be,I would start by checking fuel pressure at fuel rail,you said your pump was new,but I had the same problem and it was because the outlet hose in the tank came loose,i had to pull pump and reconnect it. It can also be your,IAC,coil,icm,cat,dist. You will need to work through it.

mike37

x2
pump
filter
or regulator

91familyxj

whats the iac and the icm and cat. sorry I just dont know all the abbreviations yet. lol

kansas_jeeping

IAC = Idle Air Control valve
ICM = Ignition Control Module
CAT = Catalytic converter??? not sure on the last one, still new myself

91familyxj

thanks. Ya i was pretty sure on the catalytic converter but for all i know it could be something else. lol Ya i just let it cool down and looked over my vacume line and they looked good and i just kinda did a over look at it all and still nothing. So i started it up and drove it down the street with no problem and then when i was pulling it in my drive way bam it started doing it so I dont know if its something to do when it comes up to running temp thats making it start acting up

91familyxj

ok so I checked the fuel press. and its 100% accorting to my book. Its right inbetween 30 to 40 and when I dissconnect the vac line it goes up to 42ish. I looked at my cap and rotor and they seem fine. So now its down to coil and dist. What part on the coil goes bad just the pick up or is it a stator? Im lost on that part. Any more ideas? Thanks

cherokee nick

our 1997 cherokee did that same thing and I had a friend diagnoisis it down to the distributer. come to find out that the pick up was collecting dust on the contacts, so we sprayed it out with electra-motive cleaner and replaced the cap and rotor. You might use quality parts. Our jeep dealership here in town said standard brand ignition parts are as good if not better than factory. we got another 65000 miles out of it.

jeepxjho

Also something that slips most people minds check you air filter.

The 4.0 has issues with spraying oil on the air filter from the pcv hose and over time soaks the air filter and cause drivablity issues seen quite a few jeeps come thru the dealership with the same issue and a oil soaked filter.

If you notice there is oil on the filter just pick up the kit chrysler made to fix it here a link to the page and also the part numbers.

http://jeep.off-road.com/jeep/articl....jsp?id=257985

smitysjeep4x4

i have had the same probalem happen to me. have you replaced your 02 sensors recenlty. if not its probally them. the jeep feels like it bogs down and stalls out everytime. first i would start with unpluggint the first 02. this is going to throw a code yourll probally get p135 or p138 its just saying about you 02s this will mostly likely fix your probally this happend for me about a year and untill i figured it out

91familyxj

Thanks guys I will be checking that tomorrow morning. Is there a way to tell if my pick up is bad and i got a new cap and rotor. I didnt check my air filter I dont know why you make a good point thanks. Its not so much of a bogging down just like power is cutting in and out and when driving it wants to die unless I keep it at a high rpm. Well again thanks guys and I will check it out and let you know how it goes. O and you said standard brand is that the brand name of it and where did you find it at?

91familyxj

Well no oil on the Air filter so thats good. I have my dist out and Im about to pick up a new pick up. Does anyone know how to do a continuity test on a coil or anything like that?

91familyxj

Well Im keeping my fingers crossed but I replaced the pick up in my dist. and so far so good I drove around all day with no problems. Thanks again guys