Jeep Wrangler Forum banner

problem starting..

3K views 5 replies 6 participants last post by  Jerry Bransford 
#1 ·
This has just became a recent problem.. sometimes im havin troubles starting the jeep... i checked the plugs.. and everything.. and then sometimes.. it just fires up.. anything?
 
#3 ·
Try turning the key over for a couple of seconds before you start it to let the fuel pump work before you crank it. Also listen to see if you can hear the fuel pump working when you turn the key into the on postion, right before the position it cranks. Just a suggestion. There was a write up on dailydrivenTJ.com that told about a problem like this and showed how to rebuild the fuel pump to fix it!!
Here ya go: http://www.dailydriventj.com/fuel_pump.shtml
 
#4 ·
Need to get to the basics.... Fuel, Fire and Air.... Ususally, air is not a problem unless your MAF sensor is offline and the ECM can't make a decision. Check the sensor and all ignition wires first.

Fuel is next. Turn the key to the "on" position and the fuel pump relay and fuel pump should energize. I would troubleshoot the relay first. It's the cheapest part to replace too. I believe the relay is located in the black plastic box in the engine compartment. Unless you have an electrical diagram and are handy with a multi-meter, just buy a new fuel pump relay.

The fuel pump is next. Check your fuel rail for pressure. There should be a schraeder valve (looks like a bicycle tire valve) on the fuel rail. Put on some safety glasses and use a small screw driver and depress the pin to release some pressure. You should get evidence of pressure and fuel. If you do not, then your fuel pump is suspect. Check the wires and voltage to the pump. If you're getting voltage and you have no pressure, then it's probably toast and needs to be replaced.
 
#5 ·
I had the same problem with my 1999 Sahara last summer. I had no pressure at the fuel rail if the Jeep sat for a few hours. So when I tried to start it the fuel pump had to re-prime the system and eventually it would start. After it started it ran fine.

The mechanic I talked to wanted me to spend $400-$600 to replace the whole fuel pump plus his labor costs. I did some research and found it was just the fuel pressure regulator on the top of the fuel pump. Cost me $118 for the regulator from the dealer. I did the work myself and the Jeep has been fine ever since. Good luck.
 
#6 ·
This is what I'd go with. Nearly any slow-to-start TJ can be cured by replacing the fuel pressure regulator. The culprit inside the regulator is the anti-drainback valve that is there to prevent fuel inside the fuel rail from draining back out of the fuel injectors and fuel rail. When they leak, a slow start after the Jeep has sat a while is the result because you have to wait for the fuel to get back up to the fuel rail. :)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top