93 grand cherokee wont start

tmeff429 · 02-21-2010, 04:06 PM

Heres what I got. Driving and the motor just dies. Try to start it the motor turns over, but wont start. The fuel pump isn't priming. I bought a new fuel pump relay and a new pump the new pump isn't priming either. I pulled the fuse to make sure it wasn't blown, and it's not. I lifted the float on the sending unit gas hand moves. What should I check next? Sometimes it will act like it's gonna start, but wont. It's got a V8 AND 4X4 if that helps. Any help would be great. Thanks

ol"blue · 02-21-2010, 04:45 PM

You need 3 things to run: fuel, spark, and air. We know you're getting air. You can check for spark, and then chase down fuel issues.
But I'd remove the air horn to TB elbow and pour a little gas, or starting fluid into the TB and see if it fires. If it fires up you know it's fuel related, so look for the problem in a fuel pump fuse, relay, ground, clogged filter, or a problem with the pump/pick-up. JMO
And Welcome to CF!
Dan

tmeff429 · 02-21-2010, 04:57 PM

I'll give it a shot. I'm assumin that the TB is the throttle body right.

ol"blue · 02-21-2010, 04:58 PM

Quote:

Originally Posted by tmeff429

I'll give it a shot. I'm assumin that the TB is the throttle body right.

That's correct.
Dan

tmeff429 · 03-30-2010, 04:12 PM

OK I replaced the fuel filter, the fuel pump relay, and checked the fuse. All checked good. I pulled the fuel line from the outlet of the fuel filter gas squirted every where. So I have gas that far. I pulled the plug, got spark. I squirted starter fluid in the TB still not starting.

What should I try now?

tmeff429 · 03-31-2010, 02:15 PM

Anybody got any ideas? What would keep it from starting?

rivercrazy · 04-01-2010, 03:42 PM

Do you hear the pump come on when you turn the key without turning the motor?

Have you tested your fuel pressure at the rail? You can rent a tester from Autozone.

Are you sure you have spark? How did you test that?

trucker · 04-01-2010, 08:05 PM

Actually there is 4 "things" you need to start: fuel, air, spark and compression.
The timing my be off. If you have compression gauge then check all cylinders. It should not have less that 100 lbs and no more that 20lbs difference. If the spark plugs are black then you have too much fuel going in. Check the oil cap for signs of oil - blown head gasket. Milky oil. There is more that just fuel,air and spark to have engine running and you have those three basics.
Time to "dig in". Mark the 1st cylinder plug and have firing order ready. Pull plugs and spin engine. With some carton at cylinder hole look for signs of water or oil. Then check compression. Did you overheat the engine?. The electrical gauges are not correct and when the temp shows high or engine lights come on most of the time it is too late. I have manual gauges added.

Willys55 · 04-01-2010, 09:20 PM

There is one thing you can try. Don't laugh because this was an issue for 93-95 GC. The rear tailgate latch completes the circuit for the vehicle security system and when it fails it sometimes causes the seurity system to arm, when it arms with the driver door unlocked you end up having no injector pulse and a weak spark at the coil because the ignition circuit has a voltage drop while cranking. (about 6 volts) Check to see if you have a good blue spark from the distributor cap to the plugs and using a test light you can see if you have injector pulse while cranking. If not try locking and unlocking the car from the drivers side using the key not the transponder

jeepfan93 · 04-03-2010, 06:39 AM

Interesting, how to check that rear latch circuit is good?

trucker · 04-03-2010, 07:27 AM

If the dome lights go out then the latch is closed. My will start with the back door open. You have fuel, spark and air. Check if the firing order is correct. Distributor my be loose and out of time. Does the engine spin very fast?

tmeff429 · 04-05-2010, 02:53 PM

yeah the engine spins good. the spark does look weak though.if the security relay is bad would it cause similar problems.

tmeff429 · 04-07-2010, 09:24 PM

Can you by-pass the tailgate circiut for the security system? If so how? Also the fuel pump is priming, but it is not as loud as it used to be. You can barely hear it priming.

trucker · 04-08-2010, 07:47 AM

The reason I asked about engine spinning fast is that you my not have compression. I would check the compression.

tmeff429 · 04-08-2010, 12:08 PM

Engine is turning over fast. It just wont start up. The battery is starting to drain. I'm gonna charge it back up, but other than that. IDK?

02-21-2010, 04:45 PM	#2
ol"blue CF Veteran 2004 Jeep Grand Cherokee My Garage Join Date: Mar 2009 Location: Tenn. and Mich. Posts: 28,040 My Photos 2004 Grand Cherokee Engine: 4.7L V8 Transmission: 545RFE Transfer Case: NV 247 Front Axle: D30 w/3.73 gear Rear Axle: D44A w/3.73 gear Tires: 245x70x16 Wrangler SRA's Lift Specifications: None Misc Accessories: HD Cooling System & Tow Package, Monroe sensa trac shocks	You need 3 things to run: fuel, spark, and air. We know you're getting air. You can check for spark, and then chase down fuel issues. But I'd remove the air horn to TB elbow and pour a little gas, or starting fluid into the TB and see if it fires. If it fires up you know it's fuel related, so look for the problem in a fuel pump fuse, relay, ground, clogged filter, or a problem with the pump/pick-up. JMO And Welcome to CF! Dan __________________ Dan '04 Grand Cherokee SE: 4.7L V8 w/235 HP, 4X4 '04 Saturn Vue: 3.5L V6 w/250 HP, AWD *"...Never Use Post Count as A Knowledge Gauge." Willys55 CBW* Member#97 *If no answer, ask here>www.CHEROKEETECH.com*** RIP Carroll Shelby http://www.carrollshelbyfoundation.org/ http://carrollshelbyfoundation.com/ If you're not breaking parts you're not making enough power!!! "I NEED MORE TRACTION, NOT MORE BOOST"

04-01-2010, 03:42 PM	#7
rivercrazy Senior Member Garage is empty, add now Join Date: Oct 2009 Location: Redlands, CA Posts: 502 My Photos 1992 Cherokee Engine: 4.0L I6 Transmission: AW4 Transfer Case: NP231 Front Axle: D30 Rear Axle: C8.25 Tires: 30" A/T's Lift Specifications: 4.5" mix-n-match Misc Accessories: Thick rubber floor mats and lots of Lucas Oil!	Do you hear the pump come on when you turn the key without turning the motor? Have you tested your fuel pressure at the rail? You can rent a tester from Autozone. Are you sure you have spark? How did you test that? __________________ 4x4 is for people who think to themselves "I'd like to drive over that!"

04-01-2010, 09:20 PM	#9
Willys55 Caracticus Potts The Mod 1996 Jeep Cherokee My Garage Join Date: Jul 2009 Location: Hainsville,NJ Posts: 3,531 My Photos 96,95,94,93 Grand Cherokee Engine: 4.0L & 5.2L Tires: 245/85R16 & 31X10.5R15	There is one thing you can try. Don't laugh because this was an issue for 93-95 GC. The rear tailgate latch completes the circuit for the vehicle security system and when it fails it sometimes causes the seurity system to arm, when it arms with the driver door unlocked you end up having no injector pulse and a weak spark at the coil because the ignition circuit has a voltage drop while cranking. (about 6 volts) Check to see if you have a good blue spark from the distributor cap to the plugs and using a test light you can see if you have injector pulse while cranking. If not try locking and unlocking the car from the drivers side using the key not the transponder __________________ Brian Perrine will be in my memory Forever.....Good Bye My Friend *NEVER said I was perfect.....just helpful.... Never Use Post Count as A Knowledge Gauge* My name is Russ, my friends call me "Doc"

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02-21-2010, 04:57 PM	#3
tmeff429 Newbie Garage is empty, add now Join Date: Feb 2010 Posts: 13 My Photos Cherokee	I'll give it a shot. I'm assumin that the TB is the throttle body right.

03-30-2010, 04:12 PM	#5
tmeff429 Newbie Garage is empty, add now Join Date: Feb 2010 Posts: 13 My Photos Cherokee	OK I replaced the fuel filter, the fuel pump relay, and checked the fuse. All checked good. I pulled the fuel line from the outlet of the fuel filter gas squirted every where. So I have gas that far. I pulled the plug, got spark. I squirted starter fluid in the TB still not starting. What should I try now?

03-31-2010, 02:15 PM	#6
tmeff429 Newbie Garage is empty, add now Join Date: Feb 2010 Posts: 13 My Photos Cherokee	Anybody got any ideas? What would keep it from starting?

04-01-2010, 08:05 PM	#8
trucker Member Garage is empty, add now Join Date: Mar 2010 Posts: 219 My Photos Cherokee	Actually there is 4 "things" you need to start: fuel, air, spark and compression. The timing my be off. If you have compression gauge then check all cylinders. It should not have less that 100 lbs and no more that 20lbs difference. If the spark plugs are black then you have too much fuel going in. Check the oil cap for signs of oil - blown head gasket. Milky oil. There is more that just fuel,air and spark to have engine running and you have those three basics. Time to "dig in". Mark the 1st cylinder plug and have firing order ready. Pull plugs and spin engine. With some carton at cylinder hole look for signs of water or oil. Then check compression. Did you overheat the engine?. The electrical gauges are not correct and when the temp shows high or engine lights come on most of the time it is too late. I have manual gauges added.

04-03-2010, 06:39 AM	#10
jeepfan93 Junior Member Garage is empty, add now Join Date: Mar 2010 Location: toms river, new jersey Posts: 94 My Photos Cherokee	Interesting, how to check that rear latch circuit is good?

04-03-2010, 07:27 AM	#11
trucker Member Garage is empty, add now Join Date: Mar 2010 Posts: 219 My Photos Cherokee	If the dome lights go out then the latch is closed. My will start with the back door open. You have fuel, spark and air. Check if the firing order is correct. Distributor my be loose and out of time. Does the engine spin very fast?

04-05-2010, 02:53 PM	#12
tmeff429 Newbie Garage is empty, add now Join Date: Feb 2010 Posts: 13 My Photos Cherokee	yeah the engine spins good. the spark does look weak though.if the security relay is bad would it cause similar problems.

04-07-2010, 09:24 PM	#13
tmeff429 Newbie Garage is empty, add now Join Date: Feb 2010 Posts: 13 My Photos Cherokee	Can you by-pass the tailgate circiut for the security system? If so how? Also the fuel pump is priming, but it is not as loud as it used to be. You can barely hear it priming.

04-08-2010, 07:47 AM	#14
trucker Member Garage is empty, add now Join Date: Mar 2010 Posts: 219 My Photos Cherokee	The reason I asked about engine spinning fast is that you my not have compression. I would check the compression.

04-08-2010, 12:08 PM	#15
tmeff429 Newbie Garage is empty, add now Join Date: Feb 2010 Posts: 13 My Photos Cherokee	Engine is turning over fast. It just wont start up. The battery is starting to drain. I'm gonna charge it back up, but other than that. IDK?

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