Delayed start problem
09-26-2007, 11:21 AM
#1
Guest
Posts: n/a
Delayed start problem
My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
it is cool. When the key is turned to run, the check engine light
does not turn on right away. There is a delay of a few seconds and
then the relays in the power distribution box under the hood start to
click rapidly. Once this happens, the fuel pump runs for a short
while and the jeep can be started. It seems like the computer is not
aware right away that the ignition has been turned to run. If I
immediately turn the key to run again (after first returning it to
lock) the check engine and fuel pump turn on normally. After letting
the jeep sit turned off for about 5-10 minutes, the problem will
return. Later in the day when it is hot, this almost never happens but
it does once in a long while, usually after sitting turned off for at
least a few hours. What could be causing this? What could cause it to
work fine on the second try?
Thanks
it is cool. When the key is turned to run, the check engine light
does not turn on right away. There is a delay of a few seconds and
then the relays in the power distribution box under the hood start to
click rapidly. Once this happens, the fuel pump runs for a short
while and the jeep can be started. It seems like the computer is not
aware right away that the ignition has been turned to run. If I
immediately turn the key to run again (after first returning it to
lock) the check engine and fuel pump turn on normally. After letting
the jeep sit turned off for about 5-10 minutes, the problem will
return. Later in the day when it is hot, this almost never happens but
it does once in a long while, usually after sitting turned off for at
least a few hours. What could be causing this? What could cause it to
work fine on the second try?
Thanks
09-26-2007, 11:34 AM
#2
Guest
Posts: n/a
Re: Delayed start problem
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-26-2007, 11:34 AM
#3
Guest
Posts: n/a
Re: Delayed start problem
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-26-2007, 11:34 AM
#4
Guest
Posts: n/a
Re: Delayed start problem
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-26-2007, 11:34 AM
#5
Guest
Posts: n/a
Re: Delayed start problem
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
You are giving the classic description of a bad main power connection.
I would suspect the body's ground connection first.
The power takes time to arc the bad place and connect. Heat can expand
connections tightening them up. Once arced the connection can work for a
while also. This will get worse usually sooner than later.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-26-2007, 11:40 AM
#6
Guest
Posts: n/a
Re: Delayed start problem
I'd check the relay first, right off the bat.
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
09-26-2007, 11:40 AM
#7
Guest
Posts: n/a
Re: Delayed start problem
I'd check the relay first, right off the bat.
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
09-26-2007, 11:40 AM
#8
Guest
Posts: n/a
Re: Delayed start problem
I'd check the relay first, right off the bat.
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
09-26-2007, 11:40 AM
#9
Guest
Posts: n/a
Re: Delayed start problem
I'd check the relay first, right off the bat.
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
nrs wrote:
> My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> it is cool. When the key is turned to run, the check engine light
> does not turn on right away. There is a delay of a few seconds and
> then the relays in the power distribution box under the hood start to
> click rapidly. Once this happens, the fuel pump runs for a short
> while and the jeep can be started. It seems like the computer is not
> aware right away that the ignition has been turned to run. If I
> immediately turn the key to run again (after first returning it to
> lock) the check engine and fuel pump turn on normally. After letting
> the jeep sit turned off for about 5-10 minutes, the problem will
> return. Later in the day when it is hot, this almost never happens but
> it does once in a long while, usually after sitting turned off for at
> least a few hours. What could be causing this? What could cause it to
> work fine on the second try?
>
> Thanks
>
09-26-2007, 11:41 AM
#10
Guest
Posts: n/a
Re: Delayed start problem
On Sep 26, 10:34 am, Mike Romain <roma...@sympatico.ca> wrote:
> nrs wrote:
> > My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> > it is cool. When the key is turned to run, the check engine light
> > does not turn on right away. There is a delay of a few seconds and
> > then the relays in the power distribution box under the hood start to
> > click rapidly. Once this happens, the fuel pump runs for a short
> > while and the jeep can be started. It seems like the computer is not
> > aware right away that the ignition has been turned to run. If I
> > immediately turn the key to run again (after first returning it to
> > lock) the check engine and fuel pump turn on normally. After letting
> > the jeep sit turned off for about 5-10 minutes, the problem will
> > return. Later in the day when it is hot, this almost never happens but
> > it does once in a long while, usually after sitting turned off for at
> > least a few hours. What could be causing this? What could cause it to
> > work fine on the second try?
>
> > Thanks
>
> You are giving the classic description of a bad main power connection.
> I would suspect the body's ground connection first.
>
> The power takes time to arc the bad place and connect. Heat can expand
> connections tightening them up. Once arced the connection can work for a
> while also. This will get worse usually sooner than later.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> - Show quoted text -
Following your advice posted in previous threads I have done the
following:
1) cleaned claps and installed new battery (it was old anyway).
2) cleaned the engine ground connection behind the dipstick bracket
3) cleaned the ground connection on the firewall just to the side of
the battery.
4) cleaned the positive connection to the power distribution box
There are a few more ground straps though. That about the heat
expanding the connections makes sense. Thanks!
> nrs wrote:
> > My '95 2.5 AX5 YJ has a strange problem, usually in the morning when
> > it is cool. When the key is turned to run, the check engine light
> > does not turn on right away. There is a delay of a few seconds and
> > then the relays in the power distribution box under the hood start to
> > click rapidly. Once this happens, the fuel pump runs for a short
> > while and the jeep can be started. It seems like the computer is not
> > aware right away that the ignition has been turned to run. If I
> > immediately turn the key to run again (after first returning it to
> > lock) the check engine and fuel pump turn on normally. After letting
> > the jeep sit turned off for about 5-10 minutes, the problem will
> > return. Later in the day when it is hot, this almost never happens but
> > it does once in a long while, usually after sitting turned off for at
> > least a few hours. What could be causing this? What could cause it to
> > work fine on the second try?
>
> > Thanks
>
> You are giving the classic description of a bad main power connection.
> I would suspect the body's ground connection first.
>
> The power takes time to arc the bad place and connect. Heat can expand
> connections tightening them up. Once arced the connection can work for a
> while also. This will get worse usually sooner than later.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)- Hide quoted text -
>
> - Show quoted text -
Following your advice posted in previous threads I have done the
following:
1) cleaned claps and installed new battery (it was old anyway).
2) cleaned the engine ground connection behind the dipstick bracket
3) cleaned the ground connection on the firewall just to the side of
the battery.
4) cleaned the positive connection to the power distribution box
There are a few more ground straps though. That about the heat
expanding the connections makes sense. Thanks!