Jump to content

4.0L Won't Start


Recommended Posts

Ok so the couple times I'm gone to start my comanche it won't start..

 

It will start after I pop the hood and move the injectors, now I have no idea what that would do in order for it to start,

 

Could it be my fuel pump not having enough output psi?

Link to comment
Share on other sites

Sounds to me like you have a bad connection/broken spot in the wiring harness. Are the retaining clips for the injector plugs still there? If you look where the electrical connector plugs into the injector you should see a tiny itty bitty silver clip. These clips are what keep the connector firmly attached to the injectors.

Link to comment
Share on other sites

If you can smell fuel, you should be thanking the deity of your choice that it WON'T start.

 

True story: One of my friends from NAXJA a number of years back smelled fuel and deduced that the injectors in his heavily and extensively customized MJ were leaking. So he drove to the dealership and went into the parts department to buy an O-ring set. He came out of the parts department a few minutes later to find his heavily and extensively modified MJ fully engulfed in flames. The truck was a total loss.

 

If you smell gas, DON'T drive it until you identify the problem and fix it.

Link to comment
Share on other sites

KAPUT = broken

 

Ft P Cracker is on the right track as it sounds like an electrical thing. The Fuel Pressure Regulator is not going to change it's output because you open the hood and mess with the injectors. 

 

Start the engine and watch it run.  Use a flashlight.  Look at each injector for leaks as it idles and runs.  Then look at the fuel rail connections for leaks, then look at the fuel pressure reg for leaks.  You don't want fuel leaks.  Fuel leaks cause fires.  You don't want a fire.  Fix the leaks first before you do anything else.  Then chase down the starting problem.

Link to comment
Share on other sites

I only mentioned starting it to detect a leak as the rail/connectors/injectors WILL leak if there is in fact a leak when it's running.  You may be able to find a fuel leak simply by turning the key to the ON position.  If there is a leak in the fuel rail connectors, it may show up, but it won't show up in the injector bodies unless it's running.  The stock injectors are known to leak between the metal and plastic part.

 

If the injector bodies are leaking, they need to be replaced.  You'll get sticker shock if you go to a parts place and ask how much they are...they list at about $50 EACH.  A better alternative is something like these. 

 

http://www.ebay.com/itm/GENUINE-BOSCH-III-4-HOLE-UPGRADE-FUEL-INJECTORS-87-98-JEEP-4-0-TJ-XJ-YJ-ZJ-/151136329448?pt=Motors_Car_Truck_Parts_Accessories&hash=item23306d5ee8&vxp=mtr

 

I've been running these for a few years now, work great, no leaking.  DRIVING it with a fuel leak is asking for big trouble.

 

Another quite possible leak area is just after the fuel filter under the truck, driver's side.  The rubber hose connector gets rotted, and neglected and also only leaks when the ignition is ON.

Link to comment
Share on other sites

If the injector bodies are leaking, they need to be replaced.  You'll get sticker shock if you go to a parts place and ask how much they are...they list at about $50 EACH.  

 

 

And he ain't freaking kidding, the first time i had to replace a leaking injector i nearly passed out when he rang me up. "What do you mean FIFTY FIVE DOLLARS AND THIRTY SEVEN CENTS?!?!"

 

For me personally, i just went to the junkyard and plucked 2 good looking sets of FORD 5.0 injectors. The extra set was insurance in case any of them leaked. I have since put about 8,000 miles on the junkyard injectors without a single issue.  :thumbsup:

Link to comment
Share on other sites

All good info on leaks, but ...

 

... the problem here seems to be electrical on top of a suspected fuel leak. The leaks probably won't prevent the engine from starting ... but they may set it on fire. The no-start until you jiggle the injectors sounds like a wiring harness issue.

 

Trying to trouble shoot TWO problems -- which may or may not be interrelated -- is never fun.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...