Hard Start 1994 Jeep Grand Cherokee
 

I have a 94 Jeep Grand Cherokee, with a starting problem. Every morning I have to go out and turn the key to the on positon and wait for the "check engine" light to come on before it will start. This morning it took 30 - 35 minutes to get it started. It doesnt take so long to start during the day after it has been running. Another thing,as the check engine light comes on you can hear the gas pump (I am only told that is what it is) kicking in. Please help, I love my Jeep!!!

Re: Hard Start 1994 Jeep Grand Cherokee
 

Try turning the key from off then on 3-4 times then see if it will start, don't wait for the light to come on. If it starts it's the o-ring in the fuel pump return line letting the pressure leak back into the tank.
Another thing you can do is check to see if the fuel rail has proper pressure. Attach a pressure guage to the schreader valve on the rail and check the pressure while it's running. Should be around 40psi, when you shut the engine off you shouldn't lose anymore than 5psi total in 5 minutes. If you do and it keeps dropping it's more than likely the o-ring.
Other things to check, clean starter connections and ground, all ground cables (engine, chassis, and battery) are clean and tight. Clogged fuel filter. IAC is clean, TPS is working properly.
Have you checked for any codes being thrown by the PCM?

Re: Hard Start 1994 Jeep Grand Cherokee
 

Turning the key of then on did not start it. Although i dont have a pressure guage, I know that there is no pressure in the fuel rail while it is off just by pressing the fuel stem on the rail. Could it still be the o-ring? pressure regulator? or anything else that might come to mind?

How do i check for the codes?

Re: Hard Start 1994 Jeep Grand Cherokee
 

Ok, so I got error codes "12" and "55". What do these mean?

Re: Hard Start 1994 Jeep Grand Cherokee
 

12 is a holder and 55 means you've disconnected your battery recently. If there isn't any pressure in the fuel rail in the morning then it's definetly the o-ring/ fuel pump, you may be able to find a kit for the repair or you may just have to get a new fuel pump.

Re: Hard Start 1994 Jeep Grand Cherokee
 

Hi Jenna, re-read my post. Put the numbers in backwards but other than that no problem with your codes.

Re: Hard Start 1994 Jeep Grand Cherokee
 

Thank you for your help! I was really trying to narrow it down to something that wasn't the fuel Pump! ($$$) But I do realize I'll have to get a new fuel pump, Thanks again, Jenna

Re: Hard Start 1994 Jeep Grand Cherokee
 

If this isnt your DD and you can wait while one is shipped, places like rockauto have good prices on them. Much cheaper than the stealerships. Good luck with the repair.

Re: Hard Start 1994 Jeep Grand Cherokee
 

Well I wont be replacing the fuel pump just yet.....I brought it to a mechanic who hooked the pressure guage up to it. He doesnt seem to think it is the pump. The pressure is being lost slowly....and he said because it is taking so long for the pump to actually kick in for the initial start up, that it is probably electrical. Another question for you. After waiting awhile for the check engine light to come on so that i can start it up, just before i hear the fuel pump kick on there is clicking coming from the box under the hood where the fuses and relays are. Any ideas there?

Re: Hard Start 1994 Jeep Grand Cherokee
 

Try switching the horn relay for the fuel pump relay, they're the same size. Maybe you'll get lucky and it's just a relay thats on its last legs.
The only other thing that I would suggest is that your PCM is getting lazy. If you can, have the mechanic try to test it. If that's the case I have a 10.00 fix for you instead of the 500+ it will cost for a new one.
If your losing more than 5psi in under 5 minutes it is the o-ring.