1993 Jeep Cherokee Will not Start, Has fuel and spark
Im about to set my Jeep on fire! :-( I have a 1993 Jeep Cherokee with a 4.0 L high
output engine. It was -12 outside, yet The jeep started fine no problems, it was a sob to
try and get it to shift into drive, the button would not release it and allow me to put it
into D. Eventually I got it to depress and shift into drive. I drove about 1/4 mile, I
stopped at a stop sign and it stalled when I attempted to go. I have not been able to get
it to start ever since. It turns over, but never fires up. When it stalled I could smell a
weird gas like smell. Not exactly gas and not exactly exhaust. Never smelled that oder
before. Anyway, I turn the key, I can hear the fuel pump prime, I pulled a fuel line and it
is getting gas flow. Replaced the plugs, cap and rotor today, put high octane fuel as
well as home heat in the tank. Still no start. I have spark as well. I pulled a plug wire
and stuck a jumper wire in it so I could reach the ignition and still see if it was sparking
or not. It sparked, I then went straight off the coil, to test it again, this time it actually
gave me a good jolt when my finger slipped and made contact with the wire. It is
packing quite a punch electricity wise. Sparking an orange/yellow color. However, Still
no start. I cleaned the throttle body and that didnt work either. Used starting fluid, still
no start. Added jumper cables to the battery and just for grins I doubled up and added
a battery charger to give it that extra punch of power hoping that would help. Still no
start. I tried the engine code and it flashed 3 times, then flashed 5 times, then flashed
another 5 times then quit flashing all together. I have put it in neutral, still no start. Put
it back in park, no start, however this time it gave me a small giddy up type turn over
but still did not start. I tried this several more times and still nothing. I pulled a plug
wire, let it arch to ground, re-installed the wire and still no start. I am out of tricks, any
idea whats going on? Before this day it never had any hint of starting problems, never
stalled, never acted up at all. Where can I look or what can I look at next?
Check for a vacuum leak. Check the pcv valve and tubing. If it stuck open or tubing is cracked would be a major vacuum leak. Also could be egr valve stuck open.
Would this be a sudden onset of a problem like I described above? Ill give it look at tomorrow and let you know if this helps. Thank you for your time.
It would not have anything to do with you getting it into gear but it could very well be the issue with it not starting. If you are getting fuel and fire a vacuum leak would cause it not to start. Have seen the pcv tubing just crack out of the blue. Specially in colder weather.
Outstanding thank you! I did see a 90° connector that looked pretty cracked up today. Hopefully this does the trick. I can't thank you enough. Do you have PayPal? If so send me your address. I'm pretty broke but If this fixes it I'll you some cash for your time. I'm at the end of my rope and without the vehicle running my kids can't get to school and I can't get to work. I'll let you know if it works. I do have some auto mechanic schooling. Not much, just enough to do most minor repairs myself and be a danger to engines at the same time. Lol If it turns out that is not the problem I'll let you know. And until then. PLEASE to anyone ! Any mechanics out there, if you can provided me any other helpful info that solves my problem I'll gladly do the same for you and your generous time.
Try spraying some starting fluid down the throttle body. It should run for a few seconds on that. If it does then it's most likely a fuel injector problem. Check that the fuel injectors are getting a trigger signal from the ECM. If it doesn't run do a compression test. If all cylinders test low it's jumped timing. HTH. -Jim
Thank you, I have tried the starting fluid, it has no effect on the engine which just made my jaw drop. I though for sure the starting fluid would have worked. The fact it didn't work is what brought me here. How would I go about testing the ECM signal as well as a compression test? I have very basic knowledge. This type of test is a little more advanced than my understanding :-( I am starting to think I am up the creek and have no paddle.
Thanks for the offer but we share info for free. Keep us informed of your progress.
To do a compression test you'll need a compression tester. Basically it's a gauge with a hose on it that screws into the spark plug hole. You remove the spark plugs, disconnect the ignition coil, screw the compression tester into a spark plug hole, hold the accelerator pedal to the floor and crank the engine. The needle on the compression tester gauge will go up. After 4 or 5 engine revolutions you'll have your reading for that cylinder. Repeat the process for each cylinder. You should get readings of about 150 to 180 PSI. To check for the trigger signal to the fuel injectors you'll need a noid light. I'd do the compression test first. Since you know you have spark it should run on starting fluid. Because it won't leads me to believe you have no compression due to a jumped timing chain. But it'll need to be tested to be sure. HTH. -Jim
Well. I'm not sure what the heck changed. I went out this am to give the jeep another try and it decided to start. Its now starting every time, however the idle is just junk. Very low and rough, typically it sits around 900, but now its around 600/700. I hold the gas pedal and keep the RPMs up around 2 and it smooths out, however after a few seconds of holding it steady they seem to drop down in RPM and a couple second later it will rise back to 2. It just keep doing this. If it is in drive it feels like its going to stall when I am at idle. I haven't taken it for a test drive because it feels like it wont make a trip around the block with the shotty idle. Any ideas?
BTW, I havent been able to get the testing done on the compression yet
Is the check engine light on? My first thought is a bad IAC (Idle Air Control) valve or a dirty throttle body. Or possibly water in the gas. It's best to try and keep the tank as full as possible in the cold weather to avoid condensation in the gas tank and lines. HTH. -Jim
Did you end up fixing it because my jeep is having the exact same problem and I don't know what to do
Never mind. It was a coil for me, it didnt have enough spark to fire
Sorry I was away on vacation. For me the damn thing just decided to start one am. I changed the coil and have not had issues since.
Yeah it just didnt start for me so I checked everything and couldn't understand what was wrong, then I changed the coil and it fired right up
I have a 94 jeep Cherokee 4.0L w/250,000 miles and then some. I was an ASE Certified Master Mechanic for close to 30yrs. My jeep has done this twice w/coil being the issue. The crank sensor went bad once causing the same issue. The distributer acts like a cam sensor does on a newer model vehicles. Make sure that the rotor turns when cranking the engine. If the igniion rotor isnt turning it might have a broken roll pin on the dist. gear. The timing gears are made of steal as is the chain. I just replaced my timing chain for the 1st this year. It's very rare for chain or gears to fail. Make sure you set your timing at top dead center before you pull the distributer out.The crank sensor is located on the top left side of bellhousing. Jeep will not start without them functioning properly. The ECU cannot run the engine without those two signals. As for rough idle issues, 1st thing is to check for vacumm leaks with a can of brake clean. Spray it around the intake where it mounts to engine. If the idle rises and smooths out your intake manifold is leaking. Make sure all your vacumm lines are connected and not leaking before you remove intake. Jeeps also has a map sensor that uses vacumm to help with idle control(most engines won't run unless connected). The IAC sensor is located on the throttle body. Easy way to do a quick check if sensor is faulty is to tap the sensor/w screwdriver while engine is running. If the idle changes remove the TBI and clean it also remove the iac sensor and clean out the iac housing. I hope that helps with this issue an others.
I have a 94 jeep Cherokee 4.0L w/250,000 miles and then some. I was an ASE Certified Master Mechanic for close to 30yrs. My jeep has done this twice w/coil being the issue. The crank sensor went bad once causing the same issue. The distributer acts like a cam sensor does on a newer model vehicles. Make sure that the rotor turns when cranking the engine. If the igniion rotor isnt turning it might have a broken roll pin on the dist. gear. The timing gears are made of steal as is the chain. I just replaced my timing chain for the 1st this year. It's very rare for chain or gears to fail. Make sure you set your timing at top dead center before you pull the distributer out.The crank sensor is located on the top left side of bellhousing. Jeep will not start without them functioning properly. The ECU cannot run the engine without those two signals. As for rough idle issues, 1st thing is to check for vacumm leaks with a can of brake clean. Spray it around the intake where it mounts to engine. If the idle rises and smooths out your intake manifold is leaking. Make sure all your vacumm lines are connected and not leaking before you remove intake. Jeeps also has a map sensor that uses vacumm to help with idle control(most engines won't run unless connected). The IAC sensor is located on the throttle body. Easy way to do a quick check if sensor is faulty is to tap the sensor/w screwdriver while engine is running. If the idle changes remove the TBI and clean it also remove the iac sensor and clean out the iac housing. I hope that helps with this issue an others. Check your ignition switch for melt down and always keep battery connection clean.
Everything you just said was right on the money. I mean right on. I forgot I had this post but everything that has been done and every problem say just as you said! Exactly just what you said. Now it runs as good as new you know your shit. Thank you!
If you were talking to me yuppieguppie thanxs for the compliment. It's nice to feel helpful. If it wasn't me ignore this post......lol
my 1993 Jeep Cherokee will not catch any fire
I do not know what to do
my 93 jeep cherokee had a failed fuel pump (replaced with new filter.) fuel pressure test passed. still wont start, i have voltage going in and coming out my ignition coil pack, through the coil wire into my distributor, but none coming out. just replaced my cap and rotor still no start. running out of ideas
I had the same problem with my 1993 jeep gc laredo 4x4. I replaced crank shaft sensor, still no start, then I replaced ignition coil and pickup coil witch is located inside the distribiter, then it started right up! I big thing to check for is if there is ENOUGH spark coming from ignition coil you need a good 3/4 of inch or a majority of the time it won't start. Once I got it started it idled really bad and rough I changed the spark plugs and ran foam to clean injectors and flushed gas tank. Now it's running like brand new!
I have a 97 4.0 gc jeep. Everything works, it has spark, fuel & compression but just would not start. The only code it gives me is 12, pcm was disconnected from power source and 55, end of codes. Any thoughts any one? Cheers
Hi Nash. A '97 model is OBD II. But the codes are OBD I. Code 12 is a reference code that let's you know that you're in diagnosis mode. Code 55 is a computer (PCM/ECM) failure. So my best guess is that something is wrong with the computer. Or the computer is wrong for the vehicle. HTH. - Jim
Thanks Jim, I'm sorry, was away for a while. That cpm was on the vehicle since 08 I purchased from the local junk yard. Here is something that can be considered as ridiculously incomprehensible, that is to me of course. Playing around with the jeep this morning, changing relays around, mistakably replaced the fuel relay in the wrong location. Really, a vacant unconnected spot. I turned the key and after 3 attempts, the jeep started & ran for 3 to 5 seconds and stopped. I tried several times after naturally, quite excited but no start! I then rechecked for fuel at the rail and discovered there was none. Thats when I noticed the fuel relay was in the wrong location. So then, I removed the breather and poured a bit of gas in the throttle so as to duplicate the magical moment, and after 3 attempts it fired up again and lasted 4 to 6 seconds. I then replaced the fuel relay in its appropriate location and absolutely nothing happen. Back to crank no start… Now, I'm really confused! No relay and a little bit of fuel in the throttle, starts after about 3 to 4 attempts. This of course, is with the 98 pcm in place. I then replaced with the 97 pcm, same results. Remove the relay pour fuel in the carb, starts after 3-4 attempts.Now keep in mind that all grounds and power on the pcm connectors have been verified. All known electrical components seems to be functioning as designed. An energized pin # 86 on the fuel relay with ignition on and a 3 to 5 second ground activation on pin # 85…. ***Every installed electrical components have been verified operational. *** Any thoughts out there?????
My 97 4.0 gc jeep starts up and run for about 10 seconds and dies. Fuel & soot found on all 6 spark plugs. Can some tell me whats my problem… Nash
My 97 go 4.0 only starts with the fuel pump disconnected with a little starter fluid in breather. Just would not start when connected to pump even with starter fluid What's exactly is happening here? ????
Of course, it only runs for about 10 seconds. No fuel! Any ideas anyone? ??
I have a 93 Jeep Grand Cherokee,its getting plenty of fuel to the rail but not firing. I have changed plugs,wires,cap,button,map sensor,pcv valve and hose,i have also changed the crank sensor,as well as the sensor on the throttle body and still nothing. I am about ready to by a stick of dynamite and blow it up. can anybody please give me any ideas on what else i can do to get it to fire.
ok so i have an 89 Cherokee with the 4.0. i'm getting spark and fuel and it only doesn't start sometimes. and usually if i let it sit for about 6 hours it will fire right up. I've replaced the ignition switch and that solved the problem once but it's back to doing the same thing
My 93 Jeep GC would not fire after replacing the radiator, water pump etc, etc. Figures out, if you unhook the battery, the anti-theft needs to be reset for the thing to start. rear hatch door, three clicks to the right. car started right up. Not sure if anyone else has Anti-theft,but.......
OMG! 93 ZJ, 4.0L I6 MEI - I thought I had written the problems I encountered when I read the yuppieguppies' description at the beginning of this thread - I am so glad I tried one more time before I Craigslisted it. Then reading several people replaced the coil and no more issues. Read TDJ383's diagnosis and troubleshooting analysis. Play sounds of trumpets blaring and angel's singing in huge Halleluia Chorus along with the thundering pipe organ - At last, the path to The Holy Grail was given by TDJ383! May your name be praised forever in the halls of ZJ Owners everywhere! Finally a solution. I took my testing tool and held it a 1/2" from the ground while in the #2 plug wire - nothing. I decreased the gap slowly and finally at 1/4" gap it sparked very weakly and unreliably and it took an 1/8" to get a weak but mostly steady spark. I have replaced the fuel pump, fuel filter, fuel pressure regulator, crankshaft position sensor, distributor including the camshaft position sensor, all of the sensors, MAP switch, idle control, etc. and the PCM. Still no change and the warmer the engine got, the less it would run and not start. I am on my way to get a new $40 coil and hope this does the trick. I will follow up here and on several jeep sites I am on. Thank you again yuppieguppie and TDJ383! You guys ROCK!
Hey Kevin - I have also done all of that to mine - vacuum tests perfect, fuel pressure is perfect, new everything in the fuel system except injectors as they are fine. Replaced everything in the ignition system EXCEPT the coil. I read on another board where many guys are having the EXACT SAME SYMPTOMS and changing the coil did it. I checked my spark tonight because after 5 months I finally had a helper. It would barely jump 3/16" and was weak. I checked the spark on a 00 Ford Windstar and it was jumping 3/4"-1" with no problem and a super strong spark. I'll be on yours that when you can get it started and running, the more the engine heats up the worse the symptoms get until it dies and no amount of cranking will make it start for more than a second or two until it cools down completely. Back in the day, that is exactly how coils began to break down - the hotter the engine got, the less they fired a solid spark. I bought a coil tonight and will replace it in the AM and I'll post my results on here. If it works, a SWEET $40 fix!
It was absolutely the coil. I replaced it this morning and it purrs like a kitten and accelerates quickly, wraps up to 5000 RPM easily with no missing or cutting out, no loss of power. It maintains performance and smoothness while cold and up to temperature with all accessories on full. If your Jeep gets squirrely, get a helper to turn the key while you are holding the plug wire bare metal clip about 1/2" from a good ground and look at the quality of the spark. It should be bright and strong, even out to a 3/4" gap. If you are having to hold it within 1/4" or less - replace the coil. It will be the best $40 you EVER spent on your Jeep.
My 93 jeep cherokee works but won't start it turns over what could be wrong with it
Were the vacuum line located
might be able to help me I have a 94 grand Cherokee limited with the 4.0 in it I replaced the pick up rotor button crank sensor and coil... I am not getting any fire to the coil
try grounding the engine to the battery, sometime the ground goes bad and it will have no fire to the plugs
here is my question. 1991 jeep cherokee. wants to start, but will not run. pour gas in the throttle body and as long as there is gas it runs, replaced fuel pump, filter, return valve, have great gas pressure, even changed the ECM. seems the injectors do an start up firing, but don't continue so it can run.
Charles, this was one of the symptoms I was having at one point. One thing to keep in mind is there are several things happening at the same time while starting. When you first turn on the key, the starting relay is engaged, along with the fuel pump relay...now, a timing sequence begins that requires the engine to start and stay running within a timing "window" - if the engine starts, the starting sequence is completed properly and the fuel pump relay is locked in and stays engaged. If not, the FPR drops off to prevent the fuel system from dangerously overloading the engine with fuel. Basically what I'm saying is you need to arm yourself with the right sets of tools/diagnostic equipment and familiarize yourself with the complete starting/running conditions flow chart, etc. Knowing these things and having the testing procedures down in your mind will make it much easier to self diagnose/repair your Jeep.
Charles. The anti theft system is preventing the Jeep from starting. It will let it run for a few seconds then quit. If you keep pouring gas into the throttle body it will run. The anti theft turns off the injectors. Go to all the doors including the rear hatch and lock and unlock several times. This should solve the problem. The anti theft relay can be removed after you get it running so you will not have this problem again. The relay is located on the right side of the drivers area of the center console. I believe it is maroon in color, but it's been awhile since I removed mine. Good Luck.
nope, i have fuel pressure while cranking, even replaced the fuel pump again just to be sure. and no its not the anti theft checked that too. unless the relay is bad and will not reset. im thinking the injectors are clogged, giving just a spray of fuel at max pressure but not enough to keep it running, am going to pull the fuel rail and see what kind of spray i get. am welcome to any suggestions though.
i have a 1994 jeep cherokee m/t replace all the sensors and coil. have good spark at the coil and plugs. the shut down and fuel reply will not engage. I can jump the fuel relay and the fuel pump works. I get a 12 and 55 codes. which was told 12 means battery disconneted and 55 means end of code. is my PCM/ECM bad?
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