87 xj hard starting issues....
just got this jeep from my buddy....i dont know much bout the renixs..so heres my prob....if the jeep has been sitting for a few days it is a pita to start...takes forever....once its runs it idles like crap...hit the gas an it wants to die....if i let it idle like crap for a few mins it clears up an idles fine...once i drive it every now an then il notice a power loss....almost feels like a clogged cat converter...any ideas where to start what to look for
Senior Member
Joined: Apr 2012
Posts: 735
Likes: 0
From: Los Banos CA
Year: 2000
Model: Cherokee
Engine: 4.0
Check your fuel pressure regulator. Sounds like its bleeding fuel into your intake. My buddy's 88 did the same thing. If left untreated it will overtime clog the cat so sounds like its been doing it for a long time.
CF Veteran
Joined: Feb 2011
Posts: 3,074
Likes: 0
From: Bergen County, New Jersey U.S.A.
Year: 1990 Laredo
Model: Cherokee
Engine: 4.0 Inline 6 Renix
Are all your grounds good and clean? Click on the link in my sig it will help you with renix trouble shooting...
renix are great just take a little time to get right
renix are great just take a little time to get right
CF Veteran




Joined: Nov 2010
Posts: 5,841
Likes: 117
From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
Don't forget about the importance of fresh tuneup hardware to quick starting.
Fresh Champion copper plugs gapped to .035, new plug wires, distributor cap, rotor and fuel filter.
The above is possibly the best money you can spend on any "new-to-you" vehicle.
**Fuel pressure can easily be verified. You should have 31 psi at idle. Then disconnect the vacuum line leading to the fuel pressure regulator and pressure should jump to approximately 39 psi. Be darn sure that the vacuum line is pulling good vacuum line and if it is wet with fuel, you have a ruptured fuel pressure regulator
**Catalytic converter performance can easily be tested with a vacuum gauge. SEARCH for the procedure.
Fresh Champion copper plugs gapped to .035, new plug wires, distributor cap, rotor and fuel filter.
The above is possibly the best money you can spend on any "new-to-you" vehicle.
**Fuel pressure can easily be verified. You should have 31 psi at idle. Then disconnect the vacuum line leading to the fuel pressure regulator and pressure should jump to approximately 39 psi. Be darn sure that the vacuum line is pulling good vacuum line and if it is wet with fuel, you have a ruptured fuel pressure regulator
**Catalytic converter performance can easily be tested with a vacuum gauge. SEARCH for the procedure.
CF Veteran
Joined: Feb 2011
Posts: 3,074
Likes: 0
From: Bergen County, New Jersey U.S.A.
Year: 1990 Laredo
Model: Cherokee
Engine: 4.0 Inline 6 Renix
Also I just noticed you have a 87 which is the renix with the c101 connector make sure that is cleaned and dielectric greased... You can look up what that looks like hope that helps
Thread
Thread Starter
Forum
Replies
Last Post
seansr
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
13
Oct 20, 2025 02:48 PM
Blackcherokee290
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
28
Jan 8, 2025 11:36 PM
Scott Medina
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
3
Aug 29, 2015 12:35 AM
Ye Ol' Cherokee
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
0
Aug 22, 2015 01:43 PM
CCKen
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
3
Aug 20, 2015 08:07 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)



