stan'sredxj

I've changed just about everything! The only 2 parts that I haven't changed are the fuel injectors and the MAP sensor and I'm still at a loss. Here's the problem: Drove it home 2 weeks ago Wednesday, tried to start it Thursday morning, it started and then died within 30 to 45 seconds. When it's running, it sounds normal (For MY Jeep), as it's dying, it sounds like it's not getting fuel, or air, but the pressure relief valve sprays like I'm told it should. I'd take it to a mechanic, but it won't stay running long enough for me to drive it there. Just in case it's another bad fuel pump, I'm in the process of replacing it, again! ( what a pain!). Why I'm replacing it again is, as it turns over, 1, I don't hear the fuel pump kick on and 2, it seems to take an exceptionally long time for it to start. Any help and suggestion would be a godsend right now.

Here's a list of replaced parts:
*Fuel pump
*Fuel Filter
*Fuel Regulator
*TPS (Throttle Position Sensor)
*Air Filter
*Ignition Module
This list came to just over $300 that I didn't have, but how much I love my Jeep. I really need my rig. For the type of work I do, I need a 4x4 Cherokee. I've been reduced to using my Chevy Colorado and it just doesn't cut it. EVERY time I take it, I get multiple flat tires. I want my Jeep back! Again. Thanks for any suggestions and help.

superj

your pump doesn't come on if you just turn the key to run, not start? mine does, i can hear it pressurizing the system.

yours is eating pumps? since you replaced the filter, is there a crimped line or something? is your tank full of junk and its burning your pump out?

tannerp89

if your not hearing the fuel pump come on it could be a wiring issue...
but if youve got pressure to the rail your pump should be fine.
have you looked at the IAC? could cause the not wanting to idle/dieing...
have you considered misfires? are you tripping a CEL?
check your ignition also....
and PM'd you a link to a FSM....

SeriousOffroad

The fuel pump is energized for 2 seconds by the PCM at Key ON and doesnot get energized again until the PCM senses that the engine is running.

The pump is powered by 12vdc through a 30amp Bosch-style relay in the Power Distribution center (PDC). A faulty ground wire, or chassis ground will generate high resistance and possibly burn out the pump.

Clean all of your electrical connections and grounds and invest in a Fuel Pressure Gauge. Just because there is fuel at the rail doesn't mean it's at the correct pressure. You'll also beed it to determine whether or not your Fuel Pressre Regulator is functioning properly.

PM on the way shortly....

Vindicator9000

So you say you *are* getting fuel at the pressure relief valve? That seems to tell me that it's not fuel pump.

I notice that crank sensor isn't on your list. Your symptoms sound suspiciously like mine when my CPS went out.

Man, I would LOVE an FSM link if you have a second.

ct67_72

you need to see if you have codes.
with the money you spent you could have had it towed and diagnosed.
as someone else mentioned the crank sensor could definitely be the culprit.
and as also stated, just because fuel comes out of the rail does not meat that there is sufficient pressure.
But you are only guessing with out actually checking anything. If it runs and dies, I would assume that there should be a code.
This is where you need to start before you buy any more parts.

TheJerm

Throwing money at a problem is not the right way to fix something, just a waste of time and you still have the problem.

1st is fuel. Get a fuel pressure gauge for like 30 bucks and hook it up to verify the pump is working to spec and not dieing on you, if there isnt enough pressure than the injectors wont fire. could be what frankz said with the relay.

2nd is spark. This is related to the KPS or crank position sensor (CPS or camshaft position sensor controls the injectors). Test it with a voltmeter to verify that its working correctly when its hot. That FSM link should have what the voltages are for all the various sensors or a regular Haynes manual should, idk i have a FSM and it tells you everything

3rd is air. Again test the IAC or TPS with a voltmeter and a FSM

The old renix systems are a pain to figure out whats wrong because you have to go around and test all the sensors to see whats messing up, no CEL. New parts without testing is like flushing money down the toilet.

casualties

Parts greanades suck, I would check the iac motor. I had a similar issue with a long start and very rough idle and an occasional stall, cleaned the iac and she ran great for a day. Swapped the iac and have not had to look back since.

ct67_72

can you keep it running with the throttle? if not its not related to the iac.
and if you get codes, CMP is CaM Position sensor, and CKP is CranKshaft Position sensor

stan'sredxj

I appreciate all the great ideas/suggestions. What I like about my part store (since I spend sooooo much time there) is that I can return the part if it isn't what I need. Store credit is awesome! LOL. Anyway, I'm going to try the IAC next. I have to try really, really hard to keep it going after I start it. But it eventually dies no matter how much I feather the gas. If the IAC doesn't correct the problem, I will definitely replace the CPS. I don't really mind throwing money at the problem, because every part that I've replaced looked like it came with the rig originally. I figure it's time, or going to be, to replace them anyway. I really do appreciate it and will let everyone know when I fix it what the problem actually was. Like the song goes, "You don't know what you've got 'til it's gone". I really miss my rig. I'm sure I lose ALOT of man points driving my daughter's "Girlified" toyota corolla around with all the pink hawaiian flowers on it. LOL

DM_MKV

I am having the same issue. Have you checked the fuel pressure relay? I had pressure one day in the ail and now I have none. I hear the pump trying to do something but no fuel is getting to the rail. Does anyone think I can just rule it my fuel pump or is there some other test I can do?

fantic238

Try to jumper the fuel pump relay between pin 87 and 30 with a thick wire, this will make the pump turn continuously and if it doesn't die anymore you will know that you have a faulty relay.

biztyke

to those saying he should look for codes, it is a renix jeep, codes are only made and stored while the jeep is running and besides that the chances of a shop having something that can read it is slim to none. renix needs to be multimeter diagnosed.

from the sounds of it i would also suspect the crank position sensor. i would also check the ballast resistor on the right fender next to the air box, just jump the wires together. i had very similar symptoms as you have and changed out the CPS, but it turned out to be a loose connection on that ballast resistor.

stan'sredxj

Well, Just replaced the IAC and it still does the same thing. I ran a can of Seafoam through the engine and found out that my exhaust gasket was blown, so I replaced that, it runs much quieter now. That's a plus. lol. Anywho. I'm going to try to replace the CPS. The more I think about it, it could just be a bad fuel pump again. I'm running out of options. I just might have to limp to the mechanic. Can you adjust the TPS? If so, how? Oh yeah, I was trying to take off the new TPS and the screw heads are stripped. Joy, Joy, Joy! Again, thanks for the help.

stan'sredxj

ok. just replaced the map sensor. now it won't start. looked in the engine compartment after my last try, and saw a small billow of smoke. it wound up coming from the starter relay. the (as you look at it from the battery) top right wire is literally ash. i have no idea where it goes or what it does. Please help. I'm going to replace the starter relay. thanks again and i apologize for sounding like an idiot, but the haynes manual, when it comes to wiring, is not user friendly (I need photos). I got this thing to learn mechanical skills and so far it has helped, but this is the most craziest of situations that i've come across yet. Again, thanks for putting up with my antics.