Sputtering and dying HELP - Page 6 - JeepForum.com
 3Likes
Reply
 
LinkBack Thread Tools
post #76 of 79 Old 09-06-2019, 09:04 AM Thread Starter
JDNightFox
Registered User
1989 YJ Wrangler 
 
Join Date: Feb 2010
Location: AZ
Posts: 153
Quote:
Originally Posted by Siva283 View Post
Quote:
Originally Posted by JDNightFox View Post
OKAY SO I just finished my drive finally, it did end up doing it again but this time I think I have the problem

New fuel pump was installed this morning before I left. I bought a fuel filter to also change out just in case but didn’t do it at the time. I survived most of the day but once the tank dropped to about half full and the temperature rose above 90 degrees, it did it again

I swapped out the fuel filter on the side of the road, and the old filter was very empty inside (and rattling)

So I think my problem is this:

This Jeep was an MPI fuel injection swap. I installed an inline pump and filter on the frame, but decided to put the filter BEFORE the pump so that the pump would last longer. The problem with that is during hotter weather I think the filter is restricting the flow just enough to vapor lock the whole fuel filter, which then makes the pump have no fuel flow, which drops the fuel rail pressure to 0.

After it died again, with the new filter on, I tapped on it and the filter sounded hollow inside. I then ran the pump manually and after about 30 seconds the pressure went back to normal and it started again.


So in total, my problems have been:

when it died, I could hear the fuel rail boiling. This was because the fuel pressure regulator had a broken o-ring which would prevent the rail from holding pressure when the pump wasn’t running

After installing the fuel pressure gauge, I could see the rail pressure would drop to 0 which means the pump wasn’t pumping correctly, so I grabbed it with my hand while trying to start but could feel it running still so I thought that wasn’t it.

At this point, I think my original pump might have been good as is, and I just need to re route my fuel filter to go after the pump instead of before it

What type of fuel filter are you running? Even with the pressure regulater working the pump still have to move alot of fuel since the return is on the rail. Sounds like your filter may be causeing a restriction well obviously it does so I should say to much of a restriction for the pump to over come and it loses prime. I would at a minimum put the filter after the pump. You may want to looks at an MPFI intank set up. There is a reason the factory went to that set up. I would think one being it would be very hard for the pump to lose prime. I have a 15 gallon sender assembly still I think. I am happy to check. It would need a fuel pump though as its got a cheap chinese one in it and I definitly dont suggest them as my last 3 have lasted about a month each.
It’s the stock 1994 inline fuel filter, I think it’s a high pressure filter but I’m unsure how they were routed from the factory

I think they have a 1 way backflow valve on them too?

JDNightFox is offline  
Sponsored Links
Advertisement
 
post #77 of 79 Old 09-06-2019, 09:19 AM
Siva283
Registered User
 
Siva283's Avatar
1993 YJ Wrangler 
 
Join Date: May 2011
Location: Baltimore
Posts: 4,849
Quote:
Originally Posted by JDNightFox View Post
Itís the stock 1994 inline fuel filter, I think itís a high pressure filter but Iím unsure how they were routed from the factory

I think they have a 1 way backflow valve on them too?
No the filter does not have a check valve. Fuel can flow both ways. They are direction because of the filter media itself. From the factor its an intank pump and the filter is mounted on the passenger side frame rail right by the shock mount on the rear side. The filter I do believe though I could be wrong is designed to have fuel pushed through and not pulled through like your current set up

1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

Quote:
Originally Posted by Magnum View Post
I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim
Quote:
Originally Posted by ldso View Post
. It started with a $200 axle, and a few thousand dollars later I was done :)
Quote:
Originally Posted by Luuca View Post
diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...
Quote:
Originally Posted by Overhead View Post
this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.
Siva283 is offline  
post #78 of 79 Old 04-07-2020, 07:41 PM Thread Starter
JDNightFox
Registered User
1989 YJ Wrangler 
 
Join Date: Feb 2010
Location: AZ
Posts: 153
Quote:
Originally Posted by Siva283 View Post
No the filter does not have a check valve. Fuel can flow both ways. They are direction because of the filter media itself. From the factor its an intank pump and the filter is mounted on the passenger side frame rail right by the shock mount on the rear side. The filter I do believe though I could be wrong is designed to have fuel pushed through and not pulled through like your current set up
Yeah I'm pretty sure it's a high pressure fuel filter just for that reason

I also have a custom exhaust that routes out the side, which when on the highway the airflow pushes the hot exhaust air past the filter so that doesn't help during hot weather
JDNightFox is offline  
 
post #79 of 79 Old 04-09-2020, 07:49 AM
Siva283
Registered User
 
Siva283's Avatar
1993 YJ Wrangler 
 
Join Date: May 2011
Location: Baltimore
Posts: 4,849
Quote:
Originally Posted by JDNightFox View Post
Yeah I'm pretty sure it's a high pressure fuel filter just for that reason

I also have a custom exhaust that routes out the side, which when on the highway the airflow pushes the hot exhaust air past the filter so that doesn't help during hot weather
Heatsheild made from a soda can could greatly help that

1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

Quote:
Originally Posted by Magnum View Post
I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim
Quote:
Originally Posted by ldso View Post
. It started with a $200 axle, and a few thousand dollars later I was done :)
Quote:
Originally Posted by Luuca View Post
diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...
Quote:
Originally Posted by Overhead View Post
this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.
Siva283 is offline  
Reply

Tags
4.0 , starting issue , YJ

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











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