aa7kn

I have a 1997 Grand Cherokee 4.0 automatic trans. when I go to start it up in the morning or after work, I have to turn the key on and off many times until I see the gauges activate, then it will start. IF i try to start it up without the gauges activating, it just turns over and won't fire. I have noticed that after it starts and warms up, I can go do things around town and as long as it doesn't cool off completely it starts back up every time, only after it sits over night or all day at work do I have this problem. I have changed the ignition switch already and it didn't help. I hope someone here can help me, this is my DD and it is really becoming a problem. Thanks in advance

zjWaggy

Well In a no start situation an engine needs 3 things: compression, spark, and fuel. After reading these symptoms i'd start checking over your fuel system to begin with since you say you need to turn the key over many times before cranking it over to regain fuel pressure that may have been dropped due to a faulty fuel pressure regulator.

dave1123

That's got to be it. Every time you turn on the key, the fuel pump only runs for about 2 seconds, enough to pressurize the fuel rail. A faulty pressure regulator would allow drain-back of the fuel overnight. If you have an external fuel filter, the regulator is in the filter, most of the time.

IDK why the gauges don't activate.

aa7kn

yes I am thinking the fuel pump won't turn on until the dash gauges actually come on also, I have to turn on and off the ignition switch many times and when I see movement in the gauges in the gauge cluster, then it will start. so I am sure the pump and gauges ( dash) are not powered on until the key is switched on and off many times....the ignition switch was already changed..

Bustedback

You're over thinking it. The gauges have a delay before they read at first power. You're fuel pump is bleeding pressure and causing the fuel rail to lose its prime. When you cycle the key the pump is coming on each time and pressurizing the rail enough to allow the engine to start. Replace the pump and be done with it.

aa7kn

yep I am probably over thinking it, I will check the pressure regulator and then the pump. I did pull the fuel line off of the fuel rail and turned on the key, Gas came out real fast and I could not hold it with my finger, a lot of pressure. I will go with the pressure reg. first. Thanks for the input, and getting me thinking in the right direction....

zjWaggy

Goodluck!

Bustedback

There's a check valve in the pump assembly that keeps the fuel from draining back. Bad check valve equals long crank times and rough running at start up.

twinkiedooter

Your problem sounds a lot like my 97 XJ and her hissy fits. I found that if I turn the key and don't start but let the bong bong chime until finished THEN turn the key my Black Beauty will start but it sometimes has to think about it and then the engine catches and turns over. I also found a trick that keeps the fuel in the line a little bit longer as well. When you put it in park to turn off the engine... let the engine idle for at least to the count of 5 then turn off. Sometimes this does help when starting up again.

I do find that when it is very cold out my BB will start right up but now since it's in the 80's it has to think about it. I have a brand new fuel pump sitting in my junk room and have not had the time or money to have my mechanic guy put it in. Should have done this last year (face palm) but she does start sooner or later I just don't take the key and turn and crank immediately but let the bonging go on and THEN turn the key. If she doesn't start after say to the count of 5 - I will then turn the key off and start all over again. I do not stall out at stopsigns or lights either or at high speed over 40... It's just annoying having to baby her to start. Have owned her now one year to the day (No less) and she still has her hissy fits. I tried new plugs, wires, new coil, etc and that did not fix her start problems. I have 186K on her now having put about 3K since 8/18/14 so you can see I don't go anywhere...just around town stop and go a lot of short trips to supermarket, Advance Auto and Lowe's.

Also another cute trick is to keep the fuel tank full as she tends to start right up on a full tank. I did have some issues with the fuel pump not being properly seated but when tank was dropped my mechanic tightened pump up but that didn't help. Shoulda had him change it out but didn't own the new fuel pump at the time.

dave1123

Question; when you turn the key on, do the warning lights come on? Is the delay just the gauges? I'm thinking PCM slow warming up which could be bad capacitors.

aa7kn

thanks for all the input...no just the delay in the gauges....and as far as the XJ goes I had that problem with my XJ and when I pulled the injectors and cleaned them real good and put on new o rings man she started right up everytime...thanks guys for the input....Big help, My 97 Grand Cherokee is getting a new regulator and if that doesn't do it I will go with a fuel pump.....thanks

twinkiedooter

Try this..... I just had my throttle body cleaned and put a new throtle body gasket in. The old one seemed to be cracked in a few places obviously resulting in a vacuum leak of sorts.
Now my engine has some get up and go and I don't have such a hard time starting her anymore. I'll know in a few days if the new gasket was the problem of why I had starting problems. A new gasket is around $2 so that is not a big expense.

aa7kn

went to a local JY and they had a guy there that was pretty well versed on Grand Cherokee's like mine, he said it might be the Computer??? I thought no way, but he had about 15 of them on a shelf and the 3rd one we tried worked like a charm. everything works and starts the first time every time now. some computers game me a transmission light, so started good but the guages wouldn't work, but like I said, the 3rd one did it, so if anyone is having this strange symptom like I had, might check your computer...thanks guys for all the input...