88 renix 3k idle with brake light fuse installed
09-19-2017, 10:14 PM
#1
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88 renix 3k idle with brake light fuse installed
Like it says, I just bought an 88 xj with no brake lights. Ran good enough to get home, with hand signals. Got to digging around and found missing fuses, so I popped a few in. Started it up and the idle raised to 2500 then 3000 rpm. Pulled the fuses with it running and no change. Shut it off and restarted and 750 rpm idle. Popped them back in and idled fine still. Shut off and restarted and same 2500/3000 rpm idle.
What kind of sorcery is This? I'm baffled.
What kind of sorcery is This? I'm baffled.
09-19-2017, 11:14 PM
#2
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Year: 1988
Model: Cherokee
Engine: 4.0
Note from DJ
Which fuses were missing
Fuses & Circuit Breakers 1984-88 AMC/Jeep
http://jeep.zerok.ru/index.php?page=105
Which fuses were missing
Fuses & Circuit Breakers 1984-88 AMC/Jeep
http://jeep.zerok.ru/index.php?page=105
09-20-2017, 01:13 AM
#3
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Year: 1998
Model: Cherokee
Engine: 4.0
I used to own a 88 cherokee, had the same issue. Now, its been a few years but I believe it was the fuel pressure regulator. I pulled mine off and could see a physical crack in it. There was also a smell of fuel when left overnight. Might want to check into it, the part is cheap. Pull off the vacuum line and look for leakage.
Last edited by Theryro; 09-20-2017 at 01:15 AM.
09-20-2017, 08:07 AM
#4
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Year: 1990
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Like it says, I just bought an 88 xj with no brake lights. Ran good enough to get home, with hand signals. Got to digging around and found missing fuses, so I popped a few in. Started it up and the idle raised to 2500 then 3000 rpm. Pulled the fuses with it running and no change. Shut it off and restarted and 750 rpm idle. Popped them back in and idled fine still. Shut off and restarted and same 2500/3000 rpm idle.
What kind of sorcery is This? I'm baffled.
What kind of sorcery is This? I'm baffled.
Sounds like an intermittent TPS issue.
Go to my website below and do Tips 1 through 5 before doing anything else.
09-20-2017, 02:18 PM
#5
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Couldn't find your site. Someone else somewhere else sent me to one of your pages and it was full of good info.
I've tested the throttle position sensor and the iac, both work good, tps has no flat spots. There are four wires going to the brake light switch, two in a plug off the side and two(red and blue) in spade connectors coming straight off the switch. Pull them all off the switch and start it up and still get a 2k3k idle. Shut it off, pull fuses, start and idle is 750.
. I understand that this shouldn't affect idle, but it does. I'm sure the wiring has been hacked a little just can't figger this out.
I've tested the throttle position sensor and the iac, both work good, tps has no flat spots. There are four wires going to the brake light switch, two in a plug off the side and two(red and blue) in spade connectors coming straight off the switch. Pull them all off the switch and start it up and still get a 2k3k idle. Shut it off, pull fuses, start and idle is 750.
. I understand that this shouldn't affect idle, but it does. I'm sure the wiring has been hacked a little just can't figger this out.
09-20-2017, 03:14 PM
#6
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Year: 1998
Model: Cherokee
Engine: 4.0
Couldn't find your site. Someone else somewhere else sent me to one of your pages and it was full of good info.
I've tested the throttle position sensor and the iac, both work good, tps has no flat spots. There are four wires going to the brake light switch, two in a plug off the side and two(red and blue) in spade connectors coming straight off the switch. Pull them all off the switch and start it up and still get a 2k3k idle. Shut it off, pull fuses, start and idle is 750.
. I understand that this shouldn't affect idle, but it does. I'm sure the wiring has been hacked a little just can't figger this out.
I've tested the throttle position sensor and the iac, both work good, tps has no flat spots. There are four wires going to the brake light switch, two in a plug off the side and two(red and blue) in spade connectors coming straight off the switch. Pull them all off the switch and start it up and still get a 2k3k idle. Shut it off, pull fuses, start and idle is 750.
. I understand that this shouldn't affect idle, but it does. I'm sure the wiring has been hacked a little just can't figger this out.
Maybe I'm a little confused, but you pull the fuses OUT and the idle goes up? Is this consistent? You can recreate this over and over?
09-20-2017, 04:42 PM
#7
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Www.cruiser54.com
Do the grounds first. Tip 1. Do Tip 3 also.
Tip 5 verifies a good ground path for the sensors.
Sometimes bad grounds will cause a component to seek another component's ground and wreak havoc.
Did you test the TPS at the flat 3 wire connector or the square 4 wire one?
Do the grounds first. Tip 1. Do Tip 3 also.
Tip 5 verifies a good ground path for the sensors.
Sometimes bad grounds will cause a component to seek another component's ground and wreak havoc.
Did you test the TPS at the flat 3 wire connector or the square 4 wire one?
Last edited by cruiser54; 09-20-2017 at 05:28 PM.
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09-20-2017, 11:07 PM
#9
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Fixed it
Got a little time today so I swapped the two wires with spade connectors to opposite posts on the brake light switch. I guess it was confusing the torque converter lockup solenoid screwing up everything it could.
09-21-2017, 06:58 AM
#10
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Year: 1990
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Has it fixed it? .
09-21-2017, 07:17 AM
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Year: 1989 xj sport 2dr
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Engine: 12 hole bosch Injectors
Could it some how be causing a vacuum leak in cruise control system when its energized. Sounds like this is his switch............
09-21-2017, 07:23 AM
#12
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Year: 1990
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