89 XJ - Stalling at Low RPM
#1
89 XJ - Stalling at Low RPM
Looking for some help, recently bought an 89 XJ with 140k miles. Drove it home 2 hours without a problem. Now it is stalling at low RPMs. It wont start unless I give it gas.
I replaced TPS, IAC, Air Filter, CPS, Distributor Cap and Rotor, Spark Plugs, battery is 100%, Fuel pressure is good.
I discovered that the ground from the battery to the chassis was missing, so I added that. I am truly stumped and looking for help. The only other idea I have is to clean all of my other grounds?
After replacing the ground do I need to get it up to a certain speed for a time frame to get things reallocated? truly lost at this point.
I replaced TPS, IAC, Air Filter, CPS, Distributor Cap and Rotor, Spark Plugs, battery is 100%, Fuel pressure is good.
I discovered that the ground from the battery to the chassis was missing, so I added that. I am truly stumped and looking for help. The only other idea I have is to clean all of my other grounds?
After replacing the ground do I need to get it up to a certain speed for a time frame to get things reallocated? truly lost at this point.
#2
CF Veteran
Join Date: Aug 2020
Location: SoCal
Posts: 1,763
Received 470 Likes
on
384 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
How did you test the fuel pressure? Pushing the Schrader to see if it squirts is not enough.
Put a gauge on it. With the vacuum line attached and engine running, it should be about 31 psi. Pulling the vacuum line (and plugging it) should raise the fuel pressure to 39PSI.
Do you hear the pump prime when you first turn the key to run (don't crank yet)? You should hear it hum for a few seconds then stop.
Put a gauge on it. With the vacuum line attached and engine running, it should be about 31 psi. Pulling the vacuum line (and plugging it) should raise the fuel pressure to 39PSI.
Do you hear the pump prime when you first turn the key to run (don't crank yet)? You should hear it hum for a few seconds then stop.
The following users liked this post:
dmoe69 (06-21-2024)
#3
89 XJ - Stalling at Low RPM
Fuel pump turns on yes and I tested it with a gauge.
I gave up and asked a mechanic to inspect it and they couldn't find anything either. Should also mention I removed the air intake hose and made sure there was nothing wrong there.
I gave up and asked a mechanic to inspect it and they couldn't find anything either. Should also mention I removed the air intake hose and made sure there was nothing wrong there.
#5
Seasoned Member
Join Date: May 2021
Location: Western Washington
Posts: 468
Received 90 Likes
on
77 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
Did you adjust the new TPS to 17% of the reference voltage? Regardless though, what is the Ohms reading between the "B" terminal of the TPS and the negative post of the battery.
Last edited by dmoe69; 06-21-2024 at 03:28 PM.
#7
CF Veteran
Join Date: Aug 2020
Location: SoCal
Posts: 1,763
Received 470 Likes
on
384 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
In the meantime, go here:
https://cruiser54.com/?page_id=75
Tip #8 is the TPS adjustment.
Then go over to:
https://cruiser54.com/?page_id=365
And get the manual. Your 87 will be close enough to the 88 manual. Also get the Renix Fuel injection manual.
https://cruiser54.com/?page_id=75
Tip #8 is the TPS adjustment.
Then go over to:
https://cruiser54.com/?page_id=365
And get the manual. Your 87 will be close enough to the 88 manual. Also get the Renix Fuel injection manual.
Trending Topics
#8
TPS
Ok. So I checked both voltages on the TPS. One side is reading 5.1 and the other is reading .1. Of course that doesn't match up to the 17% rule, but when I am trying to adjust the .1 I cant get it to move at all. I assume this means my TPS is bad?
#9
CF Veteran
Join Date: Aug 2020
Location: SoCal
Posts: 1,763
Received 470 Likes
on
384 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
Sorry but I have to ask, did you loosen both screws?
Also check to make sure the arm on the TPS moves with the throttle. When replacing the TPS, its easy to get the arm on the wrong side so it remains stationary.
Also check to make sure the arm on the TPS moves with the throttle. When replacing the TPS, its easy to get the arm on the wrong side so it remains stationary.
#12
CF Veteran
Join Date: Aug 2020
Location: SoCal
Posts: 1,763
Received 470 Likes
on
384 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
Sorry again, but just to be clear, you're saying the TPS won't move or the voltage reading doesn't move when you adjust the TPS? When you open/close the throttle, you should see the voltage sweep as well.
If the voltage is not moving, double check the connectors. Make sure no pins backed out. Make sure the main harness connections are clean.
What brand TPS did you buy?
Here's a pic from my '88. TPS on the right, IAC on the left. Again, just verifying yours looks in order.
If the voltage is not moving, double check the connectors. Make sure no pins backed out. Make sure the main harness connections are clean.
What brand TPS did you buy?
Here's a pic from my '88. TPS on the right, IAC on the left. Again, just verifying yours looks in order.
The following users liked this post:
Saudade (06-25-2024)