Another Starting Question! Starts on the second try

cracker · Mar 17, 2005

I have a 94 XJ and I have noticed in the last two weeks the vehicle has to start on the second try at the ignition. But the vehicle always starts. If I had just stopped it and turned it off and re-started it within about an hour it will start on the first try. The battery seems to be fine too.

The vehicle runs great with 142000 miles on it and idles really smooth.

Any suggestions on what I should check?

(Forgive me but I checked to see if there was another similar question on this but had no luck so if there has, I'm sorry)

Thanks

Cracker

ChuckD · Mar 17, 2005

cracker said:
I have a 94 XJ and I have noticed in the last two weeks the vehicle has to start on the second try at the ignition. But the vehicle always starts. If I had just stopped it and turned it off and re-started it within about an hour it will start on the first try. The battery seems to be fine too.

The vehicle runs great with 142000 miles on it and idles really smooth.

Any suggestions on what I should check?

(Forgive me but I checked to see if there was another similar question on this but had no luck so if there has, I'm sorry)

Thanks

Cracker

I would check the to see if your getting enough fuel. Pump may no be priming on the first try. Jsut before you start you should hear the pump prime. Prime it first and then try to turn it over. If it starts I would be looking into a new pump.

Matthew Currie · Mar 17, 2005

ChuckD said:
I would check the to see if your getting enough fuel. Pump may no be priming on the first try. Jsut before you start you should hear the pump prime. Prime it first and then try to turn it over. If it starts I would be looking into a new pump.

I wouldn't get too alarmed about this. The check valve in the fuel pump is pretty notorious for leaking down pressure when it sits. It most likely isn't actually failing to prime in the traditional sense of pumps (i.e. it isn't sucking air or failing to pump), just taking time to repressurize the fuel injection system. If you always wait a few seconds before you crank, it will probably start all right. My 95 has been doing this for the last 50 thousand miles or so. It doesn't bother me enough to replace the fuel pump.

If you're really concerned about this, a fuel pressure gauge can be plugged into the fuel rail, and you can check the pressure when running, to ensure that the pump is indeed pumping well enough, and also check to see how long it takes for the pressure to drop when you shut down (bad check valve).

footdale · Mar 17, 2005

I posted the same exact problem here after I bought the jeep. Waiting for the fuel line to pressurize didn't do anything different. A few months later my CPS went out. After replacement it starts up perfect right away every time. Have you ever had to change your CPS yet? After reading a few other posts here from people with the same problem, I'm starting to believe that the two might be related. It's just a thought.

ChuckD · Mar 17, 2005

CPS is aways a good call, but usually you also get rough idle or it cuts out while driving. I have run into just about every ignition issue with my 93'. The last one was the connector to the coil was bad. Replaced it with a new one and it's alive again.

steveC · Mar 17, 2005

Just a footnote to footdale's message... When I got our 150K mile 95 back in december, it would crank slow and "dead" for several seconds before it lit up. After a couple of stalls, and seeing a CPS code thrown by the ECM, I replaced the CPS. It hasn't stalled since.

But, what may be relevant here, is that I noticed that I still have to crank for several seconds (or try twice) *if* it has sat for a few hours. The difference is that it's no longer "dead" during the cranking; it spins faster and sputters a little as you crank, until it starts. If we're out running errands, it fires right up while warm.

I do know that after sitting overnight, I have zero pressure in the fuel rail just by pushing down the schrader. That says that either the check valve is bleeding down, or the injectors leak, which I doubt because the oil stays very clean. Never have put a gauge on it yet, low priority repair. So I theorize that it's taking a few seconds to bleed air out while I crank, that would explain the behavior.

Anyway, I could tell a difference before and after the CPS, maybe that'll help in your diagnosis. Thought I'd throw it out...

MAP · Mar 17, 2005

I had something similar happen to my 99XJ. It wound crank fine but wouldn't seem to turn on in the same amount of time like it usually did. I didn't want to strain the starter so I would stop and crank it again. On the second try it started right up. I experienced these symptoms for about a month.

I was concerned that it could be the fuel pump as well.
The pump is a pain to change so I replaced the one other item that I know will cause hard starting as well.... the spark plugs.

I replaced the Bosch plugs with another set of the same plugs, and didn't have the problem again.
The strange thing is that the original set that gave me the hard starting problem only had 30,000 miles on them. I put almost 50,000 miles on the second set with no problem. The only reason I changed them out was because I had to get the car smogged and wanted to make sure I had a good set up plugs in there.

MAP

Matthew Currie · Mar 18, 2005

steveC said:
Just a footnote to footdale's message... When I got our 150K mile 95 back in december, it would crank slow and "dead" for several seconds before it lit up. After a couple of stalls, and seeing a CPS code thrown by the ECM, I replaced the CPS. It hasn't stalled since.

But, what may be relevant here, is that I noticed that I still have to crank for several seconds (or try twice) *if* it has sat for a few hours. The difference is that it's no longer "dead" during the cranking; it spins faster and sputters a little as you crank, until it starts. If we're out running errands, it fires right up while warm.

I do know that after sitting overnight, I have zero pressure in the fuel rail just by pushing down the schrader. That says that either the check valve is bleeding down, or the injectors leak, which I doubt because the oil stays very clean. Never have put a gauge on it yet, low priority repair. So I theorize that it's taking a few seconds to bleed air out while I crank, that would explain the behavior.

Anyway, I could tell a difference before and after the CPS, maybe that'll help in your diagnosis. Thought I'd throw it out...

Leaking injectors are unlikely. It would be pretty unusual for more than one or two injectors to leak down, and if they did it would almost certainly start and idle rough and make a lot of smoke before settling down again.

Another Starting Question! Starts on the second try

cracker

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ChuckD

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Matthew Currie

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footdale

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ChuckD

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steveC

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MAP

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Matthew Currie

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