bigblue91601

I have a 93 jeep grand cherokee v8 that will not start, it will crank but wont start. We went ahead and checked for spark and there was no spark, we do have fuel getting to the engine. We are not mechanics so we are unsure of where to go from here any help is appreciated

97grand4.0

You say not mechanics, does that mean you are looking for a referral to a qualified shop?
The usual suspects list is long, and qualified trouble shooting is recommended to avoid just throwing parts at it. That said, ..check for 5v on all the sensors, the crank sensor will cause this, followed by cam position sensor, check fuel pressure, ...do you have power in the cabin, dash lights headlights, etc?
Scan tool showing any codes or check engine light?

bigblue91601

Thank you for the response!!! I am not looking for a referral to a mechanic but just looking for advise to lead me in the right direction. I just got a multimeter so we are definitely checking the cam and crank sensor today, It also has dash lights headlights and everything else working inside. My jeep has a obd1 so I'm unable to connect it to a scan tool, unless you know of anywhere else I can plug it in to. I did that test where you turn the key on and off twice and the check engine light flashes. I got code 12 which means weak connection or something like that. Battery terminals were just cleaned and it's making a good connection as far as I can tell. Check engine light is off and any advise is greatly appreciated please

97grand4.0

Check the crank sensor and get back to us. At that point if that comes up empty I will have to decline advising, just not enough data to work with, hope you understand. Maybe someone else can jump in.

bigblue91601

Yeah i totally understand! I appreciate any advise, we are going to check the crank sensor right now! Do you guys think its highly possible that it may be the distributor.

dave1123

Okay, here's a quick tutorial on how the system works;

Turn the key on to run, PCM wakes up and runs the fuel pump for 2 seconds to charge the fuel rails, then waits for a signal from the Crank Sensor that tells it the crank is turning.

When it gets this signal, the PCM energizes the ASD relay and the fuel pump relay. The ASD relay controls the ignition and fuel injector circuits. The ignition coil and injectors are constantly powered by 12v if the ASD relay is on and the ignition and injectors are grounded thru drivers in the PCM.

SO, check the coil primary wire for power while cranking the engine. Also check an injector for power the same way. These are 12VDC, so set your meter accordingly. I know you have no spark, but if you have no power to the injectors as well, the ASD relay isn't pulling in or the CPS isn't delivering a signal to the PCM.

If you DO have power to the injectors, chances are the problem lies with the ignition system, ie; coil and cam sensor.

That's about all I can think of for a quick diagnosis. Good luck.

bigblue91601

Dave thank you very much for that, so my wives cousin and i were working on it last night and he noticed that the spark plug wire that goes to the ignition coil to the distributor cap was shorted out and it was sparking like crazy, so we went ahead and bought spark plug wires, because it is cold where i live we only changed that shorted out wire. Once we switched it out it actually almost started! Before it was just crank and crank and nothing would happen but once we changed that wire it wants to start up but no luck just yet. He thinks that it might just be the distributor cap? What do you guys think?

97grand4.0

Of course the basics of the tune up should be checked, put the wires on it, cap and rotor, and triple check the firing order being a V8. You say you 'have' the jeep, how long, ie was it running for you then quit? I'm not familiar with the 93 v8 but I take it it's OBDI?

Kogulanathan Kasinadan

Check engine control fuse...
Try to change CPS...
Check PCM...

bigblue91601

Good evening guys i just have another silly question. I got myself a multimeter and was testing the ignition coil. When i test the primary connector it reads 01.8 and the lowest 01.5 the secondary connector reads 12. The haynes book says that the primary should read between 0.95 to 1.18ohms. It also says that if any of the connectors is not within the specs to replace. I have my ohm meter set to 200 since its the lowest setting for ohms. My dumb question is am i reading it correctly? To me it looks like the primary connector is not withing specs? Am i right in thinking this? Again i apologize if this is a silly question.

97grand4.0

Sounds like you're doing it right, and the primary is out of spec. HOWEVER, low ohm readings are difficult because any bad connection of the probes to the coil will also introduce more resistance so you always go with the lowest reading you can get. In your case that looks like 1.5 ohms, still too much.
With your report of the coil wire arcing, it's reasonable to assume some shorting or a too high resistance reading, this would mean replace coil. Also it fits with your symptoms and what has happened. I know mine was within specs above when I check it. I replaced it anyhow with an Accel, somewhat better response midrange. But if you're looking to solve a rough running or no start condition, best to swap in a junkyard one first and see if it makes any difference. I think that's a reasonable thing to try for you if it's still misfiring. my 2c

bigblue91601

Okay guys again i apologize in advance for continuing to bring this up but you guys are my go to peeps because im to broke to afford a mechanic. So if you read my first post it says its cranking but wont start and it seems to have a weak spark. So i changed my spark plugs, wires, battery, and ignition coil. My next thing was going to be distributor cap and rotor. Since i work and dont have a garage i dont always have time to work on it and its super cold where i live. Anyways, i checked the shrader valve on the fuel rail and it had fuel spill out. It didnt shoot out but it did come out. When i do the turn key diagnostics it only comes up with 12 because i replaced the battery BUT ON OCT 28TH I DID THE TURN KEY DIAGNOSTIC AND I GOT CODE 12 BATTERY DISCONNECTED 21 o2 SENSOR SIGNAL CIRCUIT 42 AUTO SHUTDOWN RELAY INDICATES OPEN OR SHORTED CIRCUIT. Having said that, it still turned on and it ran like it normally did which in my book was normal. Until it died on Dec 23rd. I SWAPPED THE STARTER RELAY WITH THE AUTO SHUTDOWN RELAY AND IT STILL CRANKS BUT WONT START. DO YOU GUYS THINK IT COULD STILL BE THE ASD RELAY? SORRY FOR THE STORY BY THE WAY.

bigblue91601

After a month of not starting I finally got it to start, I changed the spark plugs, wires, and distributor cap. But it's definitely not running the same as before :/ so when the engine is cold and just warming up it idles normally and sounds like it use to, but once it heats up is when the issues begin.
Issue number 1- I've never noticed my battery gauge fluctuate, i always thought it stayed in one place, now it reads a little over 14 on the gauge especially when I'm giving it gas
Issue number 2- it's starting to blow white smoke. Before it use to blow a bit of white smoke but only when it had been on for a while. I do lose engine coolant but not much I only fill it up once in a great while, but I definitely lose a lot of oil and I just think that's because it leaks oil. It has never heated up. Another thing is that when I come to an abrupt stop the rpms drop to 0 but doesn't turn off and it idles low but it has always idled low
Do what do you guys think issue 1 could be
and do you guys think issue 2 could be blown head gasket???

Hatsuwr

Your alternator supplies ~14V to charge the battery - no problem there.

As for your second issue... First thing I would do is check your Idle Air Control (IAC) motor, Throttle Position Sensor (TPS), and Manifold Absolute Pressure (MAP) sensor.

These are all easy enough to check with your multimeter. Your Haynes manual should have instructions for each, but I can look up specs for you if not. Be careful with the IAC if you pull it out, I've heard that it's easy to damage them by twisting or pulling the pintle.

That said, the white smoke is most likely coolant, but it'd be good to know those three above are good before tackling that.

97grand4.0

After not running for a month, it would be expected that a lot of condensation has formed in the muffler and cat. I would first suspect this and not a head gasket. My brother recently rebuilt a transmission in a chevy van, when they fired it up after sitting a month it took a good hour to blow all the water out. White smoke galore. So let it run quite a while. It could be a head gasket but I suspect not.
Your other issues . First of all if you saw a code for the O2 sensor disconnected, that will surely make it run like you describe. Other than that it sounds like the usual suspects mentioned above including the crank position sensor and or cam sensor. MOPAR only on these unless you like wasting money and doing it over again. If it has a battery temp sensor under the battery tray, it will increase the charge as a function of the ambient temperature, ie more charging when cold