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-   -   cranking problems (http://www.wranglerforum.com/f210/cranking-problems-18067.html)

Deadhed106 04-28-2008 03:26 PM

cranking problems
 
Hi, I am new to the forum, I have a 97 tj with a cranking/starting problem. My tj cranks cranks and cranks before finnally starting right up. I droped a new cps in it about a month ago, and it did not fix the problem. It hasnt bothered me, but not its starting to act like it doesnt want to start at all. Any idea where to start trouble shooting? It is not giving any codes which is confusing me even more. Battery is strong, alternator checks out as well. New plugs and wire about two months ago. Any help greatly appreciated.
:banghead:

jpdocdave 04-28-2008 03:30 PM

sounds like check valve in fuel pump, keeps pressure up when you turn it off. when it leaks down it takes the fuel a long time to get to the injectors, and eventually will not let it get there at all.

Deadhed106 04-28-2008 03:47 PM

is there any way to test the check valve to make sure its it?

richp 04-28-2008 04:19 PM

Quote:

Originally Posted by Deadhed106 (Post 223415)
is there any way to test the check valve to make sure its it?

Turn the key to on and count to 30, slowly, then turn to start, if it fires right up it's the check valve.

Triple88a 04-28-2008 04:31 PM

Rich that doesnt allways work. TJs fuel pump shuts off after 2 or 3 seconds if you dont start the jeep, thats how most other vehicles are made too so it doesn't lower the voltage of the battery. You have to turn the key to on (dash lights turn on), wait 3 seconds, then shut it to off (no need to take out the key though), then go back to on again.. wait another 3 seconds off again. Then the last time turn it to on. wait like 2 seconds and try to crank it from there.

Jerry Bransford 04-28-2008 04:34 PM

If it starts up right away after being parked no more than a few minutes but struggles to start after parked several hours or overnight, it's a leaky anti-drainback valve in the fuel pump's pressure regulator. :)

Triple88a 04-28-2008 04:37 PM

Jerry I had this problem too, i went in to target, came out half an hr later, no go lol.

Anyhow stealer replaced the whole fuel pump for free since it was on the warranty.

Deadhed106 04-28-2008 05:22 PM

OKay, I have tried starting with the tips and nothing is working..... I broke out a spark plug tester and have no spark. So, im thinking it may not be in the fuel pump, where to start?

jpdocdave 04-28-2008 05:39 PM

are you sure you're using the tester right? it is very rare to see a hard start, that starts after long cranking, and then runs fine to have to do with spark. you said you did plugs and wires, what about the cap and rotor?

Deadhed106 04-28-2008 05:50 PM

I think I might have found the problem, the cps wire looks like it got melted by the manifold.... I am try to splice it back and see if it fixes the problem.

Deadhed106 04-28-2008 06:15 PM

:banghead:okay, spliced everything back and still acting the same and no spark. Checked the distributer and rotor button and everything seems to be okay. Is there a way to check the ignition coil?

Triple88a 04-28-2008 06:26 PM

you take one of the wires, you shuvv a screw driver in there and you hold on to the metal part, that will buzz you up :)

jpdocdave 04-28-2008 07:28 PM

Quote:

Originally Posted by Deadhed106 (Post 223464)
:banghead:okay, spliced everything back and still acting the same and no spark. Checked the distributer and rotor button and everything seems to be okay. Is there a way to check the ignition coil?

put your spark tester on the coil instead of spark plug side.

so you've gone from hard start/long crank. to no start, w/ no spark? check fuel pressure, and injector pulse also, make sure you didn't lose anything else. no pulse and no spark would point to crank, or cam sensor prob possibly

richp 04-28-2008 08:40 PM

I wonder if the shorted CPS could have taken a fuse out..

jpdocdave 04-28-2008 08:51 PM

ya, something is weird. i've never seen a cps make a long crank condition like this started as. no start sure. might be more than one thing goin on here, shorted wires could have caused a fuse to blow or something. hopefully its just one prob. i think once it gets the no spark thing fixed, there still will be a long crank condition, hope not.

nater344 04-29-2008 10:30 AM

I'm having the same problem now after the dealership did the recall on the fuel sending unit....now you have to turn the key a couple of times before it will start. Otherwise it just cranks and cranks and eventually starts. I called the dealership and the sevice a**hole said, "obviously your jeep worked last week when you drove it out of here or it would still be sitting here now would it"........pissed me off!

jpdocdave 04-29-2008 01:01 PM

Quote:

Originally Posted by nater344 (Post 223755)
I'm having the same problem now after the dealership did the recall on the fuel sending unit....now you have to turn the key a couple of times before it will start. Otherwise it just cranks and cranks and eventually starts. I called the dealership and the sevice a**hole said, "obviously your jeep worked last week when you drove it out of here or it would still be sitting here now would it"........pissed me off!

what a jag, ask for the service manager, and just explain this started happening right away. sounds like a faulty unit they installed.

elch469 04-29-2008 02:49 PM

I had the same cranking problem with my 97 4cyl firsth clearly identify the problem like Jerry said if it starts up right away after being parked no more than a few minutes but struggles to start after parked several hours it's a fuel pressure regulator $137 located at the top of the gas tank.

Deadhed106 04-29-2008 07:38 PM

Okay, up date, I have replaced both the camshaft position sensor and the crankshaft position sensor and still no spark. I have test the plug with a light and removed the plug and looked for a spark, and still have nothing. Any suggestions on where to go.......

Jerry Bransford 04-29-2008 07:43 PM

Have you looked at your camshaft position sensor? It serves a similar function to and works in the same way as the crankshaft position sensor. It's inside the distributor, located under the plastic shield that is just below the rotor.

jpdocdave 04-29-2008 07:45 PM

check power to coil, if power and ground go in, and no spark out, coil is bad. usually with bad cam or crank sensors you'll have no injector pulse.

Deadhed106 04-29-2008 08:17 PM

I checked the coil earlier today, and the readings i got from my ohm meter where with in the ranges of a normal acting coil. I was wondering if there might be a sensor switch that could be telling the engine to shut down? Could my computer be defective? I have ran the test for the computer to give me a reading and nothing is happening. Could this be a sign of the computer?

jpdocdave 04-29-2008 09:58 PM

computer is very rare. you need to see if you have injector pulse, that's gonna be a good clue. just cuz a coil ohms ok, doesn't mean its good. is spark coming out of it? like i said, it needs power and ground in, and spark is supposed to come out.

Triple88a 04-29-2008 11:47 PM

Keep in mind, running a coil with the spark plug disconnected and no other place to hit ground can damage the coil so when doing tests allways make sure the coil can hit ground

jpdocdave 04-30-2008 07:38 AM

ya, usually you can put the tester on the coil and ground the other side. sometimes you gotta get creative and just make a little jumper wire.

branty 04-30-2008 09:39 AM

I just browsed the threads so I appoligize if I duplicate anyones anwser. I had a similar problem last week and it ended up being a relay to the fuel pump. On first impression, my mechanic thought it was a crank sensor on the engine. He said they are very common to go out. You might want to check both.

Jerry Bransford 04-30-2008 09:40 AM

Quote:

Originally Posted by Triple88a (Post 224057)
Keep in mind, running a coil with the spark plug disconnected and no other place to hit ground can damage the coil so when doing tests allways make sure the coil can hit ground

Sorry but that is absolutely not true. :)

Triple88a 04-30-2008 05:52 PM

thats what my auto teacher told me AFTER we burned up some kids coil on his truck in auto class :)

Jerry Bransford 04-30-2008 05:58 PM

Quote:

Originally Posted by Triple88a (Post 224272)
thats what my auto teacher told me AFTER we burned up some kids coil on his truck in auto class :)

Hate to say it but your auto teacher was wrong, or you simply misunderstood the situation or what he really said. Ignition coils and electronics don't work that way. :)

Triple88a 04-30-2008 06:03 PM

He said something about excessive electricity building up in the secondary side of the coil and melting the windings. It sparked few times on to the block and when we pulled it away for couple seconds it died. We put it back to the block but no sparks.


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