rgs80074

hello everyone

i have a
1996 jeep grand Cherokee limited
4.0l engine


I went to get into my jeep today to run to the store, it had been about a week since i last drove it.

got in and it would not start.

I could hear the fuel pump internalizing and it cranks but just will not start.

last week I replaced the tension pulley as it was supposedly bad. checked when trying to start the pulleys are turning with no problems.

i can not figure out whats wrong. I am not a mechanic (i can follow directions if i can understand them), its hot in Florida so my time i can spend outside is limited (i get heat exhausted easily). I just don't know why it ran just fine last week with no problems started up no problems ac ran no problems and now today it just don't want to run. i thought maybe for a second it was the anti theft becasue i opened up the door on the passenger side first but i closed and locked all the doors and it still would not start, actually it started for a split second then stopped. but i've been disconnecting the battery when not being used due to the headlights just turning on by themselves which i've not been able to fix.

any idea's would be greatly appreciated.






the jeep itself has been down for quite some time with just recently being fixed.

recently replaced
crankshaft position sensor (mopar replacement)
alternator
light switch (can not find the auto delay relay for issue with lights turning on by themselves)
interior bulbs replaced with led's not the dash panel

97grand4.0

check for fuel pressure with a gauge. Check for spark.

rgs80074

yes all thats on my list when i can get time to do so. i work at night so my sleeping pattern is all over the place especially with family dr visits and such.

i don't think the fuel pressure is an issue i tested that last time and it was rock steady. at least i have the tools to test for it.

i got to find videos on how to test the crank shaft position sensor make sure its getting its power and such i assume it is as its a new mopar part just installed two months ago.

there are a couple of other parts i want to check but can't think of what they are and i am not sure if i can put gasoline in the air intake area and get it to start like you can with old carb systems.

since it cranks i keep reading the starter is fine but the silenoid could be bad, so i will try the jumping of that to see.

its all about getting out there and getting it done.

now my van is wanting to stall all the time when i am not pressing the gas peddle at least in the begining or after its running no sense to how it decides it i think thats the replaced air filter.

anyways

if anyone has links to videos i should be watchign for this problem that will help me time wise a lot.

later guys

ryan

rgs80074

does anyone know or have an idea what i might want to look for.

how can i tell if the computer is messed up if i can't get it to start? all the videos i've seen you basically test it by having the vehicle running and then wiggle the wires. i can't get it to start.

i know there was a vid somewhere on how to test the crank shaft position sensor (although just replaced so probably not it).

would like to rule out anything else before replacing the computer.

any idea's would be great.

97grand4.0

It sounds to me like you may have an issue with the anti theft system being on.
Try unlocking with the key fob a couple times. Or lock and unlock the door 3 times. If that was it, my guess is the passenger or drivers or lift gate lock cylinder switch is not unlocking and the bcm sees the door being opened and locks it out.

rgs80074

Hello,

I don't have a fob for the vehicle but i had already tried locking and unlocking the doors as I thought the same thing at first.

is there a way to disable the anti theft on the vehicle to test this?

97grand4.0

Do you know if you have fuel and spark, or not, for sure?

It should disable by unlocking either front door or the lift gate, or by pressing Unlock on the fob which you don't have. Disconnecting the battery will not work it will stay in armed mode if it was. Try unlock, lock, unlock 3 times in succession. Think I read that somewhere.
When you unlock a door, do the interior lights come on? If so, that key switch is working.

rgs80074

hello,

i'll try it again today can't hurt, goign to try all 3 doors. although I am not sure thats the case. I don't have much history on the jeep only since i bought it.

want to clean the iac unit had to do that once before but never had a problem starting it then it just wouldn't stay running.

i've tested the fuel before so i have the gauge to do that will test that when i get a chance again too, although unlike last time i can't test it with the vehicle running.

I gather from posts and threads its usually 1 of 3 things,

crankshaft position sensor (very common but just replaced on mine with mopar unit)
coil not replaced or tested
and computer are known to have issues, does not look hard to replace but cost for them are 170-270.

i think somewhere i read that if i have spark and fuel then the computer is communicating and its something else.

my biggest issue is I am not a mechanic and even though i've tested my gas pressure before i don't remember how to do it and i need to look up videos to learn or refresh how to do it.

I've seen a couple of ways to test for spark did not like either one really as it was sparking inside the engine compartment and that don't seem safe to me.

but one of my biggest problems is my work and sleep schedule does not allow much time where i can work easily on my vehicles and when i get days off tend to get filled up doing other stuff.

but I plan on trying to get some work done on the jeep and van this weekend if things work out, which probably means i'll get one of three things done.