95 Wrangler Fuel Injection Problem Please Help! - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

Reply
 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 04-26-2008, 09:19 PM Thread Starter
Veteran
 
Join Date: Sep 2002
Location: Marion N. Carolina
Posts: 875
Thanks: 0
Thanked 0 Times in 0 Posts
 
95 Wrangler Fuel Injection Problem Please Help!

I have a 95 Jeep Wrangler Rio Grande 2.5 liter, 4 Cyl.

It has sat for about two years because of other issues.

It will not start, unless you pour fuel down the air breather, and as soon as you stop pouring fuel in it will die?

So we have determine that we that we must have a bad fuel pump and we did the OBD thing and we had codes 12,33,54,55. After we installed the new fuel pump it still won't start?

We did some searches on this board and decided to replace the camshaft position sensor and the crankshaft position sensor.Then we did another code check and we elminated the code 54, but we are still getting a code 33 which is air cond. related. It does not have air cond.?

So now we know that the fuel pump is working but still no electricity coming to the connector at the fuel pump? WHY? WHY? WHY?

Timber!

'70 Jeepster "LONG MAY YOU RUN"
'71 Jeepster partster
"The world is a cruel place, for an honest man!"
Timber is offline  
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 04-26-2008, 09:23 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
The problem is from the Fuel Pump Relay back... where's the circuit loosing voltage? I'd try jumpering 12 volts directly to the pump to see if the engine runs.

Last edited by LEVE; 04-26-2008 at 09:27 PM.
LEVE is offline  
post #3 of (permalink) Old 04-26-2008, 09:32 PM Thread Starter
Veteran
 
Join Date: Sep 2002
Location: Marion N. Carolina
Posts: 875
Thanks: 0
Thanked 0 Times in 0 Posts
 
You're defintely RIGHT! But I'm losing my mind...trying to figure out where the voltage is being lost?

The fuel pump WORKS! BUT we can't get a electrical current to the fuel pump, at the tank?

I'm so happy you responded, because I have read your post from the past so many times, I know...you know what you're talking about!!!

If you would prefer that I call you??? Please PM me, and I will!!!!

Timber!

'70 Jeepster "LONG MAY YOU RUN"
'71 Jeepster partster
"The world is a cruel place, for an honest man!"

Last edited by Timber; 04-26-2008 at 09:37 PM.
Timber is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 04-26-2008, 09:41 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
Take a look at Autozone for a Schemaitc. Look at Figure 29, top right side.

Note the ASD relay energizes the Fuel Pump Relay. That relay passes voltage to the fuel pump. So, make sure that relay is working. You've got spark, so the ASD relay is working. Now check to see if there's output from the Fuel Pump Relay. If there is .... check to make sure the harness is good and that the wire's not broken from the relay down under the Jeep to the Fuel pump.

Last edited by LEVE; 04-26-2008 at 09:50 PM.
LEVE is offline  
post #5 of (permalink) Old 04-26-2008, 09:49 PM Thread Starter
Veteran
 
Join Date: Sep 2002
Location: Marion N. Carolina
Posts: 875
Thanks: 0
Thanked 0 Times in 0 Posts
 
OK, I also want to mention the ASD seems to be playing games with us???

It will click twice whenever we turn on the switch, as if it is starting to initiate, then it refuses to complete the circuit???

It(ASD) has a sharp click, then kind of a clunk sound...then nothing else happens???

Timber!

'70 Jeepster "LONG MAY YOU RUN"
'71 Jeepster partster
"The world is a cruel place, for an honest man!"
Timber is offline  
post #6 of (permalink) Old 04-26-2008, 09:52 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
If the ASD were not working, then you would not have spark to run the engine while you're pouring fuel down the TBI throat. My guess is the ASD is working.
LEVE is offline  
post #7 of (permalink) Old 04-26-2008, 10:12 PM Thread Starter
Veteran
 
Join Date: Sep 2002
Location: Marion N. Carolina
Posts: 875
Thanks: 0
Thanked 0 Times in 0 Posts
 
LEVE...you're giving me great info, but if the ASD is working properly as you suggest, why is there no electrical current at the connector plug before the tank?

I know maybe I'm overlooking the obviously...BUT??? What is the OBVIOUS???

I just don't know what I'm missing here???

Thank you, kindly!!!

Timber!

'70 Jeepster "LONG MAY YOU RUN"
'71 Jeepster partster
"The world is a cruel place, for an honest man!"
Timber is offline  
post #8 of (permalink) Old 04-26-2008, 10:16 PM Thread Starter
Veteran
 
Join Date: Sep 2002
Location: Marion N. Carolina
Posts: 875
Thanks: 0
Thanked 0 Times in 0 Posts
 
OH! One more thing I need to know?

I read in the Haynes manual that the TBI, and the MPI fuel pumps look the same, but are not???

Can you shed any light on that?

Timber!

'70 Jeepster "LONG MAY YOU RUN"
'71 Jeepster partster
"The world is a cruel place, for an honest man!"
Timber is offline  
post #9 of (permalink) Old 04-26-2008, 10:29 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
The TBI and MPI fuel pumps likely do look the same, but the problem is that they're different output pump pressures. The TBI would run about 13psi, while the MPI would run at about 43psi.

The ASD is engaged by the PCM. If that's working, it passes the voltage to the fuel pump relay. So, we need to know if there is any output voltage from the fuel pump relay. If the fuel pump relay is enabled then you'll have 12 volts on it's output connector pin.

Why isn't that at voltage at the fuel pump? There could be a problem with the wiring, or the fuel pump has lost it's ground. That's a pretty common problem with a Jeep.
LEVE is offline  
post #10 of (permalink) Old 04-26-2008, 10:48 PM Thread Starter
Veteran
 
Join Date: Sep 2002
Location: Marion N. Carolina
Posts: 875
Thanks: 0
Thanked 0 Times in 0 Posts
 
OK LEVE, you're obviously a great guy! And I'm not wanting to dispute anything you're telling me.

But first of all I thought I was dealing with MPI '95 Jeep Wrangler, maybe I'm not??? Maybe it's considered a TBI? Remember I'm not as smart as I look!!! LOL

Maybe the problem is...I do have a bad PCM???

Your thoughts on that?

Timber!

'70 Jeepster "LONG MAY YOU RUN"
'71 Jeepster partster
"The world is a cruel place, for an honest man!"
Timber is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups 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 email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not 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 On
Pingbacks are On
Refbacks are On

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