Topic: need a little help with diagnosing a problem

[oldjeep]

Oops, when they replaced the fuel pump sounds like they put in one for the "bigger" tank.

Just looked and it appears that both 2.5L and 4.0L use the same pump.  Maybe just messed up the level sender when they changed it.

[Jeffy]

Oops, when they replaced the fuel pump sounds like they put in one for the "bigger" tank.

If that's the case she might want to do the 15 to 20 conversion.

[aw12345]

I still would start from the battery on what is the battery voltage when the problem occurs if its to low nothing will work right.  Even if it crancks there is a good change the injectors, fuel pump and ecm will not work. We have this problem woth 4.3 gm;s when the battery is low it will still crank and the ignition works but no fuel injectors. This might be what fooled the Pep boys guys. Get a digital voltmeter and start investigating or take it to a competent repair shop

[gomi]

I still would start from the battery on what is the battery voltage when the problem occurs if its to low nothing will work right.  Even if it crancks there is a good change the injectors, fuel pump and ecm will not work. We have this problem woth 4.3 gm;s when the battery is low it will still crank and the ignition works but no fuel injectors. This might be what fooled the Pep boys guys. Get a digital voltmeter and start investigating or take it to a competent repair shop

Got a voltmeter, the battery reads 13 and a little over 14v with the jeep running. It's a new battery though, I replaced it when the problem initially occured.

[Jeffy]

Got a voltmeter, the battery reads 13 and a little over 14v with the jeep running. It's a new battery though, I replaced it when the problem initially occured.

Now, what you'll want to do is follow the red positive cable and check the voltage on it.  You can use the frame as a ground as you move along.  You want to head towards the starter.  If you still get 12-13v on the lines then I'd suspect the starter.  Like I said before, try cleaning it off and see if it works.  The terminals are exposed on the starter, especially the ground which has a braided strap that will collect crap.

[dexetr30]

Let us know when you find the problem. Seems a lot of us have similar problems and posting your results would be helpful.

[gomi]

Quick update as to my progress. In regards to the gas tank problem I just spoke to the manager at pepboys. It turns out that they did in fact put in the sending unit to the 19gal instead of 15gal. Since they screwed up my diagnosis I came to an agreement that i would pay for all of the parts at their cost and they would refund the labor. Seems fair I suppose, as for the problem I still can't seem to figure it out. At this point I think I will use the refunded $$ to go ahead and buy a new starter and alternator and replace one, wait to see if it happens again, then replace the other and go from there. Sucks, but at least I don't have to worry about replacing a crap load of parts any time soon. I'll try testing the voltage up and down the lines in a few days wehn it isn't 10 degrees out.

[Jeffy]

Quick update as to my progress. In regards to the gas tank problem I just spoke to the manager at pepboys. It turns out that they did in fact put in the sending unit to the 19gal instead of 15gal. Since they screwed up my diagnosis I came to an agreement that i would pay for all of the parts at their cost and they would refund the labor. Seems fair I suppose, as for the problem I still can't seem to figure it out. At this point I think I will use the refunded $$ to go ahead and buy a new starter and alternator and replace one, wait to see if it happens again, then replace the other and go from there. Sucks, but at least I don't have to worry about replacing a crap load of parts any time soon. I'll try testing the voltage up and down the lines in a few days wehn it isn't 10 degrees out.

Well if the battery is staying charged then it's probably not the alternator.  If the alternator is bad you'd be running off the battery alone, till it dies.  I'd suspect either corroded wiring or the starter.

When you get a chance you can do the 15to20 gallon snip, then the gauge will read correct.

[jfrabat]

Quick update as to my progress. In regards to the gas tank problem I just spoke to the manager at pepboys. It turns out that they did in fact put in the sending unit to the 19gal instead of 15gal. Since they screwed up my diagnosis I came to an agreement that i would pay for all of the parts at their cost and they would refund the labor. Seems fair I suppose, as for the problem I still can't seem to figure it out. At this point I think I will use the refunded $$ to go ahead and buy a new starter and alternator and replace one, wait to see if it happens again, then replace the other and go from there. Sucks, but at least I don't have to worry about replacing a crap load of parts any time soon. I'll try testing the voltage up and down the lines in a few days wehn it isn't 10 degrees out.

If you are going to change the alternator, you may want to consider upgrading it to something a bit more powerful, so that you can run an e-fan in the future (dont remember if you already do); but I agree with Jeffy, and I doubt that is the cause of your problem because the battery is not being drained...

When you get a chance you can do the 15to20 gallon snip, then the gauge will read correct.

This is really easy to do (will take you about one hour), and since you already got the 19 gal sending unit, it will be like you always had the 19 gal tank (mine reads full for about 100 miles then starts to drop!).

[gomi]

Well if the battery is staying charged then it's probably not the alternator.  If the alternator is bad you'd be running off the battery alone, till it dies.  I'd suspect either corroded wiring or the starter.

When you get a chance you can do the 15to20 gallon snip, then the gauge will read correct.

good thoughts, I am not going to do the gallon snip, they are going to change it for me since it's thier mistake. On second thought, maybe thats not such a good idea . I am going to probably test the lines a bit more and then try the starter.

[dexetr30]

If you're going to do the starter yourself make sure you have the proper torx socket. The two bolts for the starter are female e-torx bolts. I think it's an e-12 if memory serves correctly.

[jfrabat]

good thoughts, I am not going to do the gallon snip, they are going to change it for me since it's thier mistake. On second thought, maybe thats not such a good idea .

You know this will increase your tank capacity for free, right?  And since you already have the 19 gal gauge, it will even read right...  Think about it; going to the gas station less often (granted, it will be more expensive to fill up, but it's not like your spending more on gas and you can always not fill it up the whole way) and having more range on the Jeep...

Anyway, just a thought!

[gomi]

If you're going to do the starter yourself make sure you have the proper torx socket. The two bolts for the starter are female e-torx bolts. I think it's an e-12 if memory serves correctly.

Thanks, that's going to be helpful, now if only it would get a bit warmer around here.