I need help quick!!!! Im thinking fuel problems.

Dj S. · **Posted:** Fri Aug 21, 2009 5:57 pm

I just tried to start my jeep, and it turns over ok but will not stay going. I have to constantly give it gas to keep it started, but once I take my foot off the gas it just goes down and cuts off. Im sure it has something to do with fuel, but just need to know if anyone has had this problem, and how did you fix it? I have a 2002 Jeep Liberty with about 95,000 miles on it. Thanks guys. I gotta make it to work this weekend.

BrendonR · **Posted:** Fri Aug 21, 2009 6:02 pm

Throttle position? It obviously doesn't idle - but does it 'try' to idle too low then stall out?

Could be a fuel pump/fuel filter as well.

Dj S. · **Posted:** Fri Aug 21, 2009 6:06 pm

No it doesnt idle at all. As soon as I let off the gas the RPM's just drop dead.

jeepskate · **Posted:** Fri Aug 21, 2009 7:02 pm

Have you checked the battery? Most auto parts stores can do a load test on it if you bring it in. There's a good chance you just need new battery. Throttle position sensor is another possibility, but I'd check the battery first.

ATXKJ · **Posted:** Fri Aug 21, 2009 8:58 pm

jeepskate wrote:

Have you checked the battery? Most auto parts stores can do a load test on it if you bring it in. There's a good chance you just need new battery. Throttle position sensor is another possibility, but I'd check the battery first.

x2 - these beasts are computer controlled -
the battery has to have enough voltage to turn on the computer
enough current to crank the engine doesn't count without the voltage.
the fact that it runs at higher rpm is a good indicator - that's when the alternator is making more voltage.

KoRnyBrad · **Posted:** Sat Aug 22, 2009 7:14 am

Mine did that and it was the idle positioner or idle sensor. Something like that. It would start but when you put your foot to it, it would die. Had to have it towed to the Stealership where they gave me a jar of vasoline and fixed it!

stumpjumper_09 · **Posted:** Sat Aug 22, 2009 8:26 am

My guess is a TPS (throttle position sensor)
IAC ( Idle air control)

Can't imagine it being battery if it has enough power to start on it's own.

stumpjumper_09 · **Posted:** Sat Aug 22, 2009 8:27 am

Also check the air filter. Could be fuel filter but that is in the tank and Is quite a project.

Dj S. · **Posted:** Sat Aug 22, 2009 9:27 am

Well I got it to start last night after reading my Hanyes repair book. I let pressure out of the gas tank by taking the gas cap off and then unpluging the disributer plug from out of the fuse box. After that I tried to start it once then tried to start it again but just let the starter keep trying to turn over for a few seconds. Next I plugged the plug back in and put the gas cap back on. Then I started it up, and it worked. I went to Advance and got sum fuel injector cleaner, and did that. The jeep will start up but its just a little rocky doing it. The fuel pump was working fine the whole time because I got underneath the jeep while my wife turned on all the electricity and I could hear the pump come on like it should, so Im still not sure what the problem is or was, but I will keep my eye out on the problem.

jeepskate · **Posted:** Sat Aug 22, 2009 12:54 pm

stumpjumper_09 wrote:

My guess is a TPS (throttle position sensor)
IAC ( Idle air control)

Can't imagine it being battery if it has enough power to start on it's own.

Read what ATXKJ wrote. Then try to imagine it.

rescu2000 · **Posted:** Sat Aug 22, 2009 7:43 pm

Guys, if you never take any advice anyone ever gives you at least listen to this. Get a cheap testing light and a good voltmeter. Learn how to use the voltmeter (it's easy). Then when you have a problem like this, log on to justanswer dot com. I NEVER promote a web site like this, but guys I had a problem with my convertible recently. I logged on there and for $13 a chrysler tech walked me through testing the crank position sensor, computer, relays, cam position sensor, coil and distributor. He told me (via chat) exactly what color the wires were that I would need to test, what voltage I should get, etc. Turned out to be the distributor ($400 remanufactured part, $1200 at the dealer). Got it changed and it's running now. I love that site now and I will use it every time I have a problem. I gave the guy an extra $10 as a tip since it took a while. But it was mostly due to me having to go buy a test light, then another one cuz I got the expensive one and needed the cheap one. I was prepared to swap out about $200 worth of sensors before I would have gotten to the distributor.

Mods: If promoting that site is against the rules, please let me know. I never do that but it was just such a positive (money saving) experience I had to.

stumpjumper_09 · **Posted:** Sat Aug 22, 2009 10:10 pm

Jeepskate. how about you imagine trying not to come across as a smart stupid. I would love to know what your credentials are for diagnosing DC electrical systems are.

ATXKJ · **Posted:** Sat Aug 22, 2009 10:24 pm

stumpjumper_09 wrote:

Jeepskate. how about you imagine trying not to come across as a smart stupid. I would love to know what your credentials are for diagnosing DC electrical systems are.

probably as good as yours for diagnosing filter problems
- I've dealt with those and typically they run at idle and die when you accelerate

as to the electrical issues - all you need to do is read posts - while sensors can and do die
the battery problems outnumber them ~10:1 so going with the odds here
and I know batteries can cause start and die - been there - done that.

stumpjumper_09 · **Posted:** Sun Aug 23, 2009 12:35 am

#1 that would be great if I was talking to you

#2 your reasoning is a little off. It is possible to have voltage without
amperage but not to have amperage without voltage. A 12vdc motor
AKA Starter takes between 35 and 40 amps at 12vdc to operate under
load and the rest of the jeep takes a max of 45 amps to run. with that
said the factory alternator puts out a min of 136 amps therefore
should be sufficient in powering the jeep unless there is another major
current (amp) draw on the system that is not being addressed.

jeepskate · **Posted:** Sun Aug 23, 2009 1:26 am

stumpjumper_09 wrote:

Jeepskate. how about you imagine trying not to come across as a smart stupid. I would love to know what your credentials are for diagnosing DC electrical systems are.

No credentials. I just know what I did, twice, when mine would start and stall. Plus it makes sense to check the easiest thing first.

ATXKJ · **Posted:** Sun Aug 23, 2009 8:46 am

Okay - general principles

1) if you post in an open thread - it's pretty much open for anyone to respond
if you want it private - use a PM

2) my reasons are very abbreviated - target is 60 characters if I expect people to read them.

3) This has almost nothing to do with the performance characteristics of Motors or Alternators
although because they are analog - motors will still work at less than 12 v
and alternators don't put out full power at idle

4) The key is the way Jeep programmed the computer and the voltage protections for it.
It's digital - it's either on or off - although starting has different parameters from running.

stumpjumper_09 · **Posted:** Sun Aug 23, 2009 12:22 pm

I guess we'll just have to wait to see what the problem is. I'm not going to spend this much time on a post because someone challenged my advice. So, deflate your heads. Not every time that someone has a different perspective on a situation does it mean that a debate has to happen or does it mean that you need to openly challenge it. You guys gave a valid diagnosis and without even reading i posted mine. Terminology my be off but still possible reasoning.

I need help quick!!!! Im thinking fuel problems.

Who is online