Hi I have a 2008 Chrysler Dodge Town and country touring. I bought it with 22000 miles. It now has 25000 miles on it
Drives nicely but I have a problem when starting up. Does not matter if engine is cold or warm.
When I turn the key it revs to 2500-3000 rpm and then comes down. This does not happen every time.
Once in a while when I turn the key it does not fire immediately but when it does it revs high.
This happened the other day and it took a good 10 seconds for it to fire up. Longer than it has ever taken. I took it to AAA and they did a diagnostics and all was fine. It would not act up when they tried to start it. Today it started with a high rev and then when I turned it off and turned on again it started but no revving.
Any help would be appreciated
Thanks
Bradley

 

I would first suspect a vacuum leak in particular downstream of the throttle plate. The engine is getting air it shouldn't. Could be any vacuum hose, intake manifold gaskets, throttle body gaskets. Next take a look at the throttle plate for smooth operation then there's the throttle position sensor or TPS and idle air control valve or IAC valve.

Your hard starts may or may not be related. One common culprit is a leaking pressure regulator on the fuel pump. It is supposed to close and maintain fuel pressure when you shut off the van. If it doesn't, pressure bleeds off not giving you enough fuel to start until the pump rebuilds pressure. You can try turning the key to run and back to off a few times before starting. That builds the pressure up. Could also be a leaking fuel injector, fuel line or pump seal. Have to add, early 5th generation vans had a problem with a bad fuel pump relay inside the TIPM.

 

Thenk you for your input. 2 Mechanics have mentioned the leaking pressure regulator on the fuel pump that could be the problem. I am printing off your response and will give it to them the next time I take it in for them to try and find the problem.How does one check for a leaking pressure regulator?
If the hard start is related to the leaking pressure regulator ,what might be causing the high RPM each time I start it . The hard start is intermitant but the high RPM at each start is almost each time.

 

"How does one check for a leaking pressure regulator?" You connect a fuel pressure gauge at a fuel test port, if equipped with one. If there isn't one hopefully the gauge comes as a kit with adapters (T fittings). Connect it at the fuel line feeding the injector loop, get the pressure up to specs then shut the engine off and watch for a large drop in pressure.

"what might be causing the high RPM each time I start it" As I stated - vacuum leak, binding throttle plate, TPS or IAC valve. Another one may be the cruise control throttle connection or bound up servo.

 

Thank you ,they have found it to be the idle air control valve or IAC valve.
Will see if this also takes care of the ocasional hard start.
I appreciate all your input