1997 wrangler hard start and sputter - JeepForum.com

 
LinkBack Thread Tools
post #1 of 11 Old 02-16-2017, 08:12 AM Thread Starter
mattyboy93
Registered User
1997 TJ Wrangler 
 
Join Date: Jan 2017
Location: Macungie
Posts: 4
Garage
1997 wrangler hard start and sputter

Hey guys, here to poke some knowledge... see if anyone else has this issue... and what they did to fix it...

My TJ: 1997 4.0 3 spd auto

It has a hard start. The wont start on first try but will on second deal. (Everything I research leads to checkvalve on fuel pump) In research I found the cycle it twice and start it on the 3rd try and it will start up right away... (that doesnt always work)

It also has an issue with sputtering. After it starts, (usually after sitting more than an hour) it sputters for a few seconds. two senerios: 1. I Idle it to warm it up: it will take a minute or two and then a 5 second sputter and its fine until I go to drive down the road. It will do the sputter again for about 5-10 seconds and wont do it for the rest of the drive.
2. I drive it right away because im in a hurry and it will sputter for 5-10 seconds as I drive down the road and wont do it for the rest of the drive.

Like I mentioned. It only does it when it sits for a little. Start it in the morning, start it to leave work etc.

Anyone else have this issue? Anyone know what it is? I have no codes on the obd reader. I had replaced the CPS and the purge valve for previous issues and I tuned it up/replaced distributor in December. It was doing the hard start and sputter before I did all that.


Matt
Mattyboy93
1997 TJ
mattyboy93 is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 02-16-2017, 08:28 AM
Jeepsr4me
Registered User
 
Join Date: Dec 2004
Posts: 9,123
Sounds like a pump issue, all of that.. Air in lines and bleed back and weak pump...

When you change it out. pop the feed line off at the engine and using compressed air blow out all the crud. I take a 2 litter plastic bottle and stick on the line that was at the tank. This will clear out anything that might be there..
Jeepsr4me is offline  
post #3 of 11 Old 02-16-2017, 08:31 AM
Jonny Jeep
Web Wheeler
 
Jonny Jeep's Avatar
1997 TJ Wrangler 
 
Join Date: Feb 2007
Location: Manchester
Posts: 5,632
The sputtering is because of a failed heating element in the upstream O2 sensor. You can confirm this by simply unplugging the sensor. If the sputter goes away, replace the sensor. Use NTK as they are the OEM supplier.

The hard start could be either the pump or the combined filter/regulator. It could also be a leaky injector. In my case I only changed the filter/regulator and have had no problems since then. That must have been about ten or so years ago.

Sent from my D5803 using JeepForum

Online factory service manuals and parts lists -
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If it doesn't work properly, look for the service manual link at the bottom of the page.
Jonny Jeep is online now  
 
post #4 of 11 Old 02-16-2017, 07:29 PM
Jerry Bransford
Administrator
 
Jerry Bransford's Avatar
2004 TJ Wrangler 
 
Join Date: Jan 2003
Location: Escondido, California
Posts: 67,565
Quote:
Originally Posted by Jonny Jeep View Post
The sputtering is because of a failed heating element in the upstream O2 sensor.
Maybe but not necessarily. I've had several bad fuel pumps over the years and the worst of them caused sputtering from not being able to pump enough fuel.

My bet is nothing more than a bad fuel pump.
If you buy a new fuel pump Mattyboy93, buy only a Bosch. Fuel pumps like from Airtex or Spectre or especially store brands are junk and they'll likely fail within the first year or two.

Our Technical Staff is working to fix our database error problem, thank you for your patience.

Getting
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
...


When you have a choice, buy American made.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Jerry Bransford is offline  
post #5 of 11 Old 02-17-2017, 12:43 AM
Jonny Jeep
Web Wheeler
 
Jonny Jeep's Avatar
1997 TJ Wrangler 
 
Join Date: Feb 2007
Location: Manchester
Posts: 5,632
If the fuel pump was causing the sputtering surely there would be more problems than just a few seconds shortly after starting "and wont do it for the rest of the drive"?

As I also said, this can be confirmed by disconnecting the sensor.

Sent from my D5803 using JeepForum

Online factory service manuals and parts lists -
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If it doesn't work properly, look for the service manual link at the bottom of the page.
Jonny Jeep is online now  
post #6 of 11 Old 02-17-2017, 11:14 AM
Jeepsr4me
Registered User
 
Join Date: Dec 2004
Posts: 9,123
Pumps with air can cavitate and take a little while to clear up. That is why I said pump, as when its running the pump can produce enough pressure. But cavitating will destroy the pump in short order.. Best to change it and be done.

I buy the pump separate from the whole kit. But if its old might as well spring for whole new sending unit and all.
Jeepsr4me is offline  
post #7 of 11 Old 02-17-2017, 11:18 AM
Jerry Bransford
Administrator
 
Jerry Bransford's Avatar
2004 TJ Wrangler 
 
Join Date: Jan 2003
Location: Escondido, California
Posts: 67,565
Quote:
Originally Posted by Jonny Jeep View Post
If the fuel pump was causing the sputtering surely there would be more problems than just a few seconds shortly after starting "and wont do it for the rest of the drive"?
The reason I wouldn't expect an O2 sensor to cause sputtering/misfires at startup is the computer doesn't look at the O2 sensor output at all until after the engine has started to warm up.

Our Technical Staff is working to fix our database error problem, thank you for your patience.

Getting
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
...


When you have a choice, buy American made.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Jerry Bransford is offline  
post #8 of 11 Old 02-17-2017, 02:22 PM
Jonny Jeep
Web Wheeler
 
Jonny Jeep's Avatar
1997 TJ Wrangler 
 
Join Date: Feb 2007
Location: Manchester
Posts: 5,632
In the OPs first post he describes the sputter as happening after a minute or two of idling. I am certain the sputter is due to a bad sensor. We will only know for sure when the OP updates the thread.

Online factory service manuals and parts lists -
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If it doesn't work properly, look for the service manual link at the bottom of the page.
Jonny Jeep is online now  
post #9 of 11 Old 02-17-2017, 07:20 PM Thread Starter
mattyboy93
Registered User
1997 TJ Wrangler 
 
Join Date: Jan 2017
Location: Macungie
Posts: 4
Garage
Apologies for the delayed reply. My app on my iphone crashes every time I go to type something and im not always near my computer.
@Jonny Jeep : If it was the upstream O2 sensor.. wouldn't you think a code would be up or the engine light was on? my obd II reader shows no codes. You are correct it starts doing it after a minute or two when idling. But it will sputter again when I drive away after it idles.

Now the other scenerio is when I turn it on and dont let it idle. Just put it in gear and drive away (if it sits for more than an hr or so ie. overnight or end of work day) it will do the sputter for 5 to 10 seconds while drivng down the road.

but what you are saying I should try isnt hard and costs nothing to diagnose.. so its definitely something to try though it could still be the pump (Hard start)
@JERRY I heard the brand and will be looking into that as well

Matt
Mattyboy93
1997 TJ
mattyboy93 is offline  
post #10 of 11 Old 02-17-2017, 09:05 PM
1Mudduck
Registered User
 
Join Date: Feb 2017
Posts: 9
My jeep did a similar thing also, turned out to be a leaking injector or one that would stick... I unbolted fuel rail and pulled injectors out of engine and turned key and had 2 that were bad ,I then upgraded injectors and installed new fuel pump assembly .... would sputter like u said at random times and loss of power , would have to disconnect battery for few min and would be ok ... mine is a 99 Tj with the 4cyl


Sent from my iPhone using Tapatalk
1Mudduck is offline  
post #11 of 11 Old 02-18-2017, 01:27 AM
Jonny Jeep
Web Wheeler
 
Jonny Jeep's Avatar
1997 TJ Wrangler 
 
Join Date: Feb 2007
Location: Manchester
Posts: 5,632
No codes for a bad O2 sensor is normal. Take your time disconnecting it, the release catch on the plug can be difficult to operate as the connector is clipped to a tab near the firewall.

Sent from my D5803 using JeepForum

Online factory service manuals and parts lists -
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If it doesn't work properly, look for the service manual link at the bottom of the page.
Jonny Jeep is online now  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome