Long Crank Before Start?

[bmrrwolfe]

I went to start the KJ at lunch today, and after cranking for a few seconds I let go, kinda puzzled it was taking so long, so I tried again, this time it took about 7-8 seconds of cranking to start.. Once started it ran fine, and I was on my way thinking it was a fluke.

After leaving work (about 4 hours of sitting) it again took 7-8 seconds to crank.. Drove home fine (only about 5 mile trip) although the idle did seem to move around a little more then usual, but not horribly.

After I got home, I let it sit for 10 minutes, and it started right up (when the engine is warm)

A little background if it could have relation. Yesterday I worked clear my P0456 that has been on for a few months, I found a evap line off the purge solenoid had rubbed a hole in it. I simply cut the hard plastic and ran 7/16" rubber fuel line. Started right up every time and ran fine all day yesterday and this morning.

First check was to look at the electrical connections, evap and vacuum lines for obvious problems in the area I was working. I did not see anything obvious but still disconnected and reconnected most of these items.

Any ideas?

 

[uss2defiant]

battery?

 

[LibertyTC]

It would be nice to have a fuel pressure gauge with you when it hesitates to start.
Either way check your fuel pressure and see where it is at.
When was the last time you changed the spark plugs, how many miles on them?

 

[bmrrwolfe]

It would be nice to have a fuel pressure gauge with you when it hesitates to start.
Either way check your fuel pressure and see where it is at.
When was the last time you changed the spark plugs, how many miles on them?

Battery is about 2 years old a duralast gold. Plugs are NGK and were done last summer about 8k on them.

Let sit for about 45-50 minutes and tried starting it. Started faster then ever. (not even a second of cranking)

Had a little under a half tank so i just put 6 gallons of 89 in and will be throwing in some fuel treatment in case I had some bad gas or water in the tank.

Going to borrow a scan tool to see if any codes are stored even though there is no CEL on.

 

[bmrrwolfe]

Let it sit for about 2 hours and fired right up. Ran a scan and it was showing P0172 and P0175. I cleared the codes and will monitor the readings.
I had issues with a rear O2 about 6 months when I replaced one side with a Bosch. Switched to an NGK and it had been good for the last 6 months.

 

[kage860]

Maybe its the fuel pump check valve? If its that, you're slowly losing fuel pressure in the rail when shut off and the pump will take a little while to build the pressure back up on cold starts. Turning the key to the on position a few times may start the fuel pump enough to give you a good start if its the check valve.

 

[uss2defiant]

maybe this might help?
P0172 and P0175 - OBD-II Trouble Codes

 

[bmrrwolfe]

Maybe its the fuel pump check valve? If its that, you're slowly losing fuel pressure in the rail when shut off and the pump will take a little while to build the pressure back up on cold starts. Turning the key to the on position a few times may start the fuel pump enough to give you a good start if its the check valve.

The check valve is built in to the fuel pump on the KJ correct?
I think I might just go buy a pressure gauge/test kit from NAPA tomorrow if the problem persists.

maybe this might help?
P0172 and P0175 - OBD-II Trouble Codes

Ironically I was just reading this site.

 

[kage860]

Yes, I belive the check valve is part of the fuel pump assembly. Harbor freight sells a pressure gauge for $20.
http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

 

[bmrrwolfe]

Yes, I belive the check valve is part of the fuel pump assembly. Harbor freight sells a pressure gauge for $20.
Fuel Pressure Tester & Fuel Injection Pump Tester

Thanks for that!

Although I started it this morning after sitting all night, and started like normal.. checked for codes after I got to work, and nothing showing..

So possibly had bad gas, or water in there, and the adding of the new/higher octane gas and fuel treatment helped, or maybe when I was working on the evap lines I did bump something and corrected it last night.

 

[tjkj2002]

So possibly had bad gas, or water in there, and the adding of the new/higher octane gas and fuel treatment helped, or maybe when I was working on the evap lines I did bump something and corrected it last night.

Most likely cause was to much ethanol in the gas,most common cause of p0172/p0175 codes these days.

 

[bmrrwolfe]

Most likely cause was to much ethanol in the gas,most common cause of p0172/p0175 codes these days.

That's interesting to hear. The station I frequent has added stickers "may contain up to 10% ethonal" to all the pumps a few months ago (or maybe they have been there and I have never noticed).. The station was built about 6-8 months ago and I have going there pretty consistently.

While going out to lunch today, it kinda started? (about the average 1 second of cranking) stumbled and died. Waited about 10 seconds, cranks for about 2 seconds then started slight stumble and within 2 seconds was fine. Once its going it drive, the power seems about normal, and the idle is pretty normal. Although I have always thought my idle was a little low (roughly 550-600) since I can remember.

 

[LibertyTC]

Ethanol loves to absorb moisture you could have some water in the tank as well.
Throw a bottle or two of water remover in there as see if that helps.
Have you cleaned the Intake air control (IAC) and ports recently?
I run non ethanol 94 octane in the Jeep and gladly pay the extra$.
50262[/ATTACH]"]

You must be registered for see images attach

I also have two bottles of Techron concentrate in the tank right now as the KJ this weekend is going on a good hwy trip!
50264[/ATTACH]"]

You must be registered for see images attach

Jeep will run smooth after a good hwy fuel system cleaning!
Edit: I had to get a dozen bottles form the USA, Concentrate not available in Canada now.

 

[bmrrwolfe]

Ethanol loves to absorb moisture you could have some water in the tank as well.
Throw a bottle or two of water remover in there as see if that helps.
Have you cleaned the Intake air control (IAC) and ports recently?
I run non ethanol 94 octane in the Jeep and gladly pay the extra$.
50266[/ATTACH]"]

You must be registered for see images attach

I also have two bottles of Techron concentrate in the tank right now as the KJ this weekend is going on a good hwy trip!
50268[/ATTACH]"]

You must be registered for see images attach

Jeep will run smooth after a good hwy fuel system cleaning!
Edit: I had to get a dozen bottles form the USA, Concentrate not available in Canada now.

I did put a bottle of gumout fuel treatment (not injector cleaner) last night. I might try to add another bottle.

Started after work no problem. Got home and it sat for 45 minutes then needed to run errands, and it gave me 6-7 second crank... First time it has done it with the engine up to temp. Went shopping it sat for 45 mins and before starting I let it sit in the ON position for a few seconds before cranking and it started right up.

 

[Leeann]

That sounds like a fuel pressure problem; I wonder about the check valve in your pump.

 

[bmrrwolfe]

That sounds like a fuel pressure problem; I wonder about the check valve in your pump.

Is there anyway to test the check valve? Being that is in the pump, I am guessing not, and also it would require the replacement of the pump assembly.

I was reading up on other posts and I found (specifically to 02-03) a replaceable fuel filter that is accessible from an access hole in trunk, was it only 02-03 that has this, or did it continue throughout the years?

 

[Leeann]

Only 02-03. After that, it's a non-replaceable part of the fuel pump assembly.

I think you can test the check valve by attaching a fuel pressure tester in place of the fuel filter. If it holds the same pressure for at least 10 mins after you turn off the key (there will be about a 5 lb drop as soon as you turn off the key, but it should hold steady after that), the check valve should be good. If it can't maintain pressure, the check valve is bad.

That's what we do on Chevy Astros to eliminate the fuel pressure regulator and injectors from the test, anyway.

 

[bmrrwolfe]

Only 02-03. After that, it's a non-replaceable part of the fuel pump assembly.

I think you can test the check valve by attaching a fuel pressure tester in place of the fuel filter. If it holds the same pressure for at least 10 mins after you turn off the key (there will be about a 5 lb drop as soon as you turn off the key, but it should hold steady after that), the check valve should be good. If it can't maintain pressure, the check valve is bad.

That's what we do on Chevy Astros to eliminate the fuel pressure regulator and injectors from the test, anyway.

Where is the fuel filter? I thought it was integrated into the fuel pump as well.

 

[Leeann]

Where is the fuel filter? I thought it was integrated into the fuel pump as well.

Ignore me. Very long day and I'm tired. The filter's part of the fuel pump. So the test would have to be done at the schrader valves on the fuel rails.

 

[bmrrwolfe]

Ignore me. Very long day and I'm tired. The filter's part of the fuel pump. So the test would have to be done at the schrader valves on the fuel rails.

Haha that is what I thought. What is the correct procedure for testing the fuel pressure at the rail?

if I'm thinking correctly you put it on the valve with the car off and turn the car to the on position and it should be reading between 40 and 45 psi?