XJ6 & XJ12 Series I, II & III 1968-1992

XJ6 choking!! Plaese help

 
  #1  
Old 08-29-2011, 05:41 PM
Junior Member
Thread Starter
Join Date: Aug 2010
Location: albuquerque NM
Posts: 21
Received 0 Likes on 0 Posts
Exclamation XJ6 choking!! Plaese help

So ive been chasing an issue in my 85 xj6 for awhile now. At first issue presented itself with sluggishness and or engine wanting to die when under load, ran fine in idle. Ive gone through plugs, wires, cap and rotor, fuel pressure regulator, fuel pump, filter, vacuum lines, and just today replaced coil and resistor, also changed gauze filters in tanks. now issue has progressed to engine choking out when it gets warm or after running for about 15 to 20 min. a mechanic " Dr Jag " here in Albuquerque told me i should check the fuel temp sensor. Said it should read 250 ohms running at 90 degrees c. now since im not a mechanic if it reads higher or lower does it need to be replaced or is something else causing this issue? before i start chasing the issue again i wanted to see if i could get some feedback. Also if anyone can think of anything else that would cause this issue id be greatly appreciated.

Matthew Rinaldi
Rio Rancho NM
 
  #2  
Old 08-29-2011, 05:56 PM
Veteran Member
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 20,147
Received 6,544 Likes on 4,856 Posts
Default

I suspect he means the coolant temp sensor?

There IS a fuel temp sensor, though. It's the brown device on the fuel rail with two vacuum hoses. You can bypass it by running a single hose from the pressure regulator to the vacuum source. It allows max fuel pressure when the fuel is hot to prevent vapor lock.

The coolant temp sensor give more trouble, historically. If it gives a "cold" reading to the ECU when the engine is actually warm or hot, you'll have too much fuel and the engine will be "running rich". If you don't have a multi-meter you can simply replace it...only $20 or so. It's on the water rail...#2 or #3 position from the front. Also carefully inspect the plug/connector forthe coolant temp sensor. Corrosion, loose wires, loose terminals will cause a problem

Cheers
DD
 
  #3  
Old 08-29-2011, 09:08 PM
Junior Member
Thread Starter
Join Date: Aug 2010
Location: albuquerque NM
Posts: 21
Received 0 Likes on 0 Posts
Default

i changed the fuel temp sensor with a used one i know works and same issue. i ran it in the garage untill it got warm and just cut out just shy of 90 degrees c. then would start and quickly shut off. i had my buddy come start it while i checked for any leaks in the boot . when he started it i noticed the fuel pump. was only staying on for a couple seconds upon ignition then turning off thus engine dying. now i know the pump is almost brand new but its a possibility that its bad. the part that makes me doubt its bad is that when the engine cools down it starts just fine and pump stays on. im baffled. any ideas???????
 
  #4  
Old 08-29-2011, 10:36 PM
Veteran Member
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 20,147
Received 6,544 Likes on 4,856 Posts
Default

Remove the fuel pump relay from the socket. In the socket find the terminals that go to the white/green wires. Use a jumper wire to apply 12 volts to the white/green wires. You should hear the pump run. If so, start the engine and see if it stays running.

The fuel pump relay is on the firewall with a couple others. Just look for the one with the white/green wires

Cheers
DD
 
The following users liked this post:
rinaldi63 (08-29-2011)
  #5  
Old 08-29-2011, 11:08 PM
Junior Member
Thread Starter
Join Date: Aug 2010
Location: albuquerque NM
Posts: 21
Received 0 Likes on 0 Posts
Default

ok im going to go try that. now another thought and this may simply be a rookie oversight. my ac needs to be charged . havent done it at all this summer because couldnt get the car running. i was reading through some pages in the haynes manual talking about the fuel cooling system. sounds to me that it uses the coolant from the ac to cool the fuel. now, if the fuel was too warm is there a sensor that would shut off the pump to keep the engine from running, kinda like a fail safe?
 
  #6  
Old 08-30-2011, 06:26 AM
doghead08's Avatar
Senior Member
Join Date: May 2011
Location: Central Jersey
Posts: 326
Received 15 Likes on 14 Posts
Default choking

i had an issue similar 2 years ago. car would start fine, idle fine and then drive like a champ. after 5 or 10 minutes of driving it would choke a little then stall. it wouldnt start back up for a while and eventually stall once it did.

replaced the ignition coil module and distributer. car has been fine since
 
  #7  
Old 08-30-2011, 07:06 AM
Veteran Member
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 20,147
Received 6,544 Likes on 4,856 Posts
Default

Originally Posted by rinaldi63 View Post
if the fuel was too warm is there a sensor that would shut off the pump to keep the engine from running, kinda like a fail safe?


No.


Cheers
DD
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickeyM
New Member Area - Intro a MUST
7
10-04-2015 05:43 PM
wonderwire
New Member Area - Intro a MUST
9
10-04-2015 05:41 PM
baskervillema
XJ XJ6 / XJR6 ( X300 )
4
10-01-2015 06:43 PM
dansxj6
XJ6 & XJ12 Series I, II & III
2
09-28-2015 08:02 AM

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

Thread Tools
Search this Thread
Quick Reply: XJ6 choking!! Plaese help


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: