97 Grand Cherokke cold start problem

[clark07]

My 1997 Grand Cherokee Laredo 6 cyl has a frequent long cranking problem when the engine hasn't been in operation for 3 or four hours.

I just replaced the plugs and plug wires and still had the problem.

The excessive cranking puts a heavy strain on the battery and my last battery only lasted 24 months.

Any help will be appreciated.

[SteveB05]

Try turning the key on (not start) wait about 2 seconds, then off, then on again for another 2 seconds. Do this three or four times, then see if it starts without the prolonged crank. If so, your not getting fuel pressure quick enough. Could be a pump, ASD relay or Injector issue.

If that doesn't work, put a spark tester on one of the plug wires, and have someone crank it. Make sure your getting spark right away. If not, this could indicate a failing crank or cam position sensor, coil or ignition switch issue.

[Dale Aeppli]

Originally Posted by clark07

My 1997 Grand Cherokee Laredo 6 cyl has a frequent long cranking problem when the engine hasn't been in operation for 3 or four hours.

I just replaced the plugs and plug wires and still had the problem.

The excessive cranking puts a heavy strain on the battery and my last battery only lasted 24 months.

Any help will be appreciated.

SOUNDS LIKE YOUR FUEL PRESSURE IS LEAKING BACK TO TANK AFTER A PERIOD OF TIME. HAVE SOMENE PUT A FUEL PRESSURE GAUGE ON IT AND CHECK FUEL PRESSURE AND HOW LONG PRESSURE IS BEING HELD. HOPE THIS IS OF HELP DALE
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[clark07]

Originally Posted by Dale Aeppli

SOUNDS LIKE YOUR FUEL PRESSURE IS LEAKING BACK TO TANK AFTER A PERIOD OF TIME. HAVE SOMENE PUT A FUEL PRESSURE GAUGE ON IT AND CHECK FUEL PRESSURE AND HOW LONG PRESSURE IS BEING HELD. HOPE THIS IS OF HELP DALE
[email protected]

Thanks to both of you for the suggestions.
I'll try the ignition key sequence test as soon as the engine has cooled down for a while and see what happens.

[clark07]

Thanks for the suggestions I 'll try the ignition key test and see what happens

[clark07]

Originally Posted by SteveB05

Try turning the key on (not start) wait about 2 seconds, then off, then on again for another 2 seconds. Do this three or four times, then see if it starts without the prolonged crank. If so, your not getting fuel pressure quick enough. Could be a pump, ASD relay or Injector issue.

If that doesn't work, put a spark tester on one of the plug wires, and have someone crank it. Make sure your getting spark right away. If not, this could indicate a failing crank or cam position sensor, coil or ignition switch issue.

As you suggested I turnrd the ignition on and off three times prior to cranking and it started right away.

Thanks

What should I ask my auto service guys to do to remedy the problem?
What's an ASD relay?

Thanks in advance

Clark

[clark07]

Originally Posted by clark07

Thanks to both of you for the suggestions.
I'll try the ignition key sequence test as soon as the engine has cooled down for a while and see what happens.

Dale

I let it sit for a few hours and then turned the ignition on for two seconds and off again three times. It then cranked very quickly.

What do I ask my auto service guys to do to remedy the problem?

Thanks for the help

Clark

[Dale Aeppli]

Originally Posted by clark07

Dale

I let it sit for a few hours and then turned the ignition on for two seconds and off again three times. It then cranked very quickly.

What do I ask my auto service guys to do to remedy the problem?

Thanks for the help

Clark

Can you hear the fuel pump relay click when you turn key on. i would check fuel pressure with a gauge. Dale

[xj31]

You are probably gonna need a new fuel pump.It needs to hold pressure when the engine is off.I doubt if you have a leaky injector because if that was the case it would run like crap when it started.

[SteveB05]

ASD is the Auto Shutdown Relay. This shuts off the fuel in the event of a crash.

I'm pretty sure the 97s have the demand delivery fuel system (most cars have a pressure releive bypass valve on the fuel rail, Chrysler has changed to only deliver fuel that is actually needed and bypass the rest in the tank, at the pump assembly).

In this set up, there is very little that can cause a pressure leak down, the pump assembly, an injector or a leaky line. XJ31 is right, if you had a leaky injector, that cylinder would have a lot of extra gas, causing it to misfire and smoke. Line leaks would be obvious, so your pretty much in the tank.

[Caribbean ZJ]

Could be your fuel pressure regulator too. But for your year i think its in the tank as well.