Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Stumped by hard start

Thread Tools
 
Search this Thread
 
Old 10-25-2015, 09:41 PM
  #1  
Newbie
Thread Starter
 
srivera's Avatar
 
Join Date: Aug 2015
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default Stumped by hard start

Alright. I am having a hard start issue sometimes. It generally seems like it mainly happens first thing in the morning or when the jeep has been shut off for more than 30mins-1hr. Normally cranks in 2-3 secs if I had to guess and when it acts up it can take upwards of 10 or more seconds. Also I sometimes get a stumble and crap idle and it clears out when it finally start. It is a 98 Model XJ.


So far I have replaced the pump, replaced the fuel pressure regulator that sits on top of the pump, took all that out and replaced with a drop in Bosch unit! everytime it seems to help it for awhile and then back to the same stuff. New upper fuel line, New CPS, new IACV, New CTS, plugs and wires seem to be in good condition as well as the cap and rotor, I have no exhaust leaks, I have upgraded the injectors to 4 hole bosch and they have never leaked down during inspection.


I am completely stumped ive tried so much stuff and still have the hard start. Any help is appreciated!
Old 10-26-2015, 06:29 AM
  #2  
Newbie
 
2000XJames's Avatar
 
Join Date: Oct 2015
Location: Long Island
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0 Inline 6
Default

It's probably your heat injector shield, I have the same problem with rough starts after my engine is being started again usually for the second time within an hour or so. It's not the worst thing ever but it did cause my check engine light to come on. Luckily it's an $8 fix and shouldn't take more than 10 min to replace.

What's actually happening is your third injector is misfiring when you start up your jeep again, the shield is basically tin foil with insulation in the middle. You would be surprised to find out that replacing it actually does solve this problem.

Last edited by 2000XJames; 10-26-2015 at 06:34 AM. Reason: More info
Old 10-26-2015, 11:07 AM
  #3  
Newbie
Thread Starter
 
srivera's Avatar
 
Join Date: Aug 2015
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

mine usually does ok on restarts. il look into that
Old 10-26-2015, 11:15 AM
  #4  
Newbie
Thread Starter
 
srivera's Avatar
 
Join Date: Aug 2015
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

it seems like the injector heat soak is more prone to the 99+ models with the horse shoe intake. I had hood risers and its already pretty cold here in Virginia. Im highly doubting that is my problem.
Old 10-26-2015, 01:33 PM
  #5  
Newbie
 
2000XJames's Avatar
 
Join Date: Oct 2015
Location: Long Island
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0 Inline 6
Default

Originally Posted by srivera
it seems like the injector heat soak is more prone to the 99+ models with the horse shoe intake. I had hood risers and its already pretty cold here in Virginia. Im highly doubting that is my problem.
Hey man it's an $8 fix and I heard from many people they've been surprised with the results, and even if that may not be the issue these shields are supposed to be replaced anyway so it can't hurt. I'm probably gonna buy myself one today to replace
Old 10-26-2015, 02:16 PM
  #6  
Newbie
Thread Starter
 
srivera's Avatar
 
Join Date: Aug 2015
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

do you have a picture? Ive never seen a heat shield on my manifold. why I was kinda thinking it was probably a 99up thing.
Old 10-26-2015, 02:17 PM
  #7  
Newbie
Thread Starter
 
srivera's Avatar
 
Join Date: Aug 2015
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

Cut the exhaust in front of the converter as a last option thinking it may be clogged. It does seem to start better and my shifts aren't as delayed and a lot smoother. However honeycomb is still intact and it doesn't sound like anything it loose in it!
Old 10-26-2015, 02:46 PM
  #8  
CF Veteran
 
toasterknight's Avatar
 
Join Date: Jan 2015
Location: Oregon Coast
Posts: 1,508
Likes: 0
Received 4 Likes on 4 Posts
Year: 1999
Model: Cherokee
Engine: 4.0L I6
Default

Originally Posted by srivera
do you have a picture? Ive never seen a heat shield on my manifold. why I was kinda thinking it was probably a 99up thing.
It was an 0331 head only issue so 2000-2001 in xj's.
Old 10-27-2015, 05:38 PM
  #9  
Newbie
Thread Starter
 
srivera's Avatar
 
Join Date: Aug 2015
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

bump
Old 10-27-2015, 05:46 PM
  #10  
CF Veteran
 
BNJeepsta's Avatar
 
Join Date: Jul 2011
Location: Warren, Pa
Posts: 2,164
Likes: 0
Received 1 Like on 1 Post
Year: 97
Model: Cherokee
Engine: 4.0L
Default

Sounds like you're bleeding fuel pressure off. Have the rail tested after the jeep has sat for a while. My 97 would do the same thing and I was losing pressure at rail when I shut it off.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
4WD4EVER
Modified XJ Cherokee Tech
28
07-28-2023 07:12 PM
ra.stewart
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
9
02-15-2021 01:47 PM
91cherokeeSC
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
41
10-29-2015 01:49 PM
Jeremy Millner
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
10
10-02-2015 02:21 PM
Crazynut1997
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
15
09-29-2015 08:14 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


Quick Reply: Stumped by hard start



All times are GMT -5. The time now is 04:52 PM.