Jeep not starting

[Thatguyjacob]

Hello all, I have looked through the threads to see if my problem has occurred. Unfortunately was unable to find an answer so here we are. I have a 1990 grand wagoneer with 123,000 miles. I bought it about 6 mo ths ago "running and driving" but it overheated like crazy. After getting it all buttoned up with new or replacement parts it now stays cool as a cucumber at about 165. Drove it for a while and got some road testing in then it died on me and wouldnt start. I ended up replacing the in tank fuel sending unit and it started up again. I ended up pulling the power steering pump so i couldnt drive it but it ran fine. So now to the real issue. I decided to change the oil and in doing so had to pull the oil filter adapter cause the filter was so seized it wouldnt budge. Got that taken care of, filled it with oil and no its no starting again. It cranks and will sputter and almost start but wont fully crank over. So i changed the icm. Nothing. Changed the Ignition coil. Nothing. Changed the battery to an optima red top, i changed the battery cables to the ones off bjs, and Ignition in the column and still nothing. Its grounded properly, cause when i swapped the battery cables i ground down the corrosion were it was at. Im losing my mind trying to figure out whats wrong. I have a new starter, alternator, and a starter relay going in this weekend in hopes one of those will solve my issue. Also added note. I tested everything with my multimeter and it all checks out. Please help me,i am just trying to drive my rig

[dodgerammit]

Help us help you just a bit more.

Not starting as in:

Cranks over fine but just won't fire?

Slowly cranks, but not fast enough to warrant a fire?

[Thatguyjacob]

Hey. So it cranks like its about to start, but it stumbles right as its about to run. then it quits

[Srdayflyer]

have you checked the wiring diagrams? a manual is invaluable to have, shotgun maintenance of throwing parts at it, doesnt get it, besides being costly and frustrating to the point of selling the truck. you need to learn the vehicle and how to diagnose problems, the sources here are great and online help from members will get it resolved, these rigs are pretty basic as far as systems go, i would check the wiring circuit diagrams pertaining to the ignition system, and check the voltage and make sure the connections are clean and not corroded and use some sort of electric dielectric grease to insure a good contact and prevent moisture issues. the oem system has proven to be problematic , i gutted my complete oem stuff and installed the holly hyperspark and sniper fuel injection system and have never looked back, and havent been stranded after doing so.

[tgreese]

Basic diagnosis - you need fuel and spark to start.

Test for lack of fuel by pouring a little gas down the carburetor, or much better, a can of ether (starting fluid). Ether is very volatile and will overcome any flooding, and isn't likely to start a fire in the carburetor.

If nothing changes with the ether, test for spark at the coil and at the plugs. Pull the wires and see if you have spark at the end of the coil wire and at the end of a spark plug wire. Bad wires are a common failure.

Throwing parts at the problem is a bad idea - you need to diagnose first.

With gas and spark, and the engine spinning, it should start if it's in time. Jumping time happens, but usually not suddenly and quietly. You can check that the engine is in time by turning the crank to the timing mark with a wrench and seeing that the distributor rotor points to the #1 cylinder wire on the distributor cap.

Realize this is a 4-stroke engine, so the timing marks will line up with #1 at TDC (top dead center) and with the rotor 180 degrees from that. The crankshaft turns twice for each complete rotation of the distributor.

[Thatguyjacob]

Hello all. Thank you for the replies and all the great advice. I do currently have a few wiring diagrams that im following to try and figure out the issue. The jeep is getting fuel to the carb and is getting spark from the coil wire. Ill check the plugs and other spark plug wires today. Also all the parts im throwing at it are left over from my previous waggy that unfortunately is no longer. So its stuff that i may as well swap over since i have it already. Also small backstpry so i dont seem like a complete newbie. This is my 2nd wagoneer and 5th project. Thank you all for the help and ill keep you updated

[devildog80]

Went down almost same rabbit hole on my '84 GW when it came home, except this was my first GW, but not my first older vehicle or project. Found bad spark plug wires were the kryptonite with mine, and did not find them for a few months. Hours/days/weeks of testing, study of schematics, rewire of PO rat nest stuff.....
Keep at it and you will find the magic smoke solution

[SJTD]

One wonders if a distributor drive gear tooth broke.

[Hooby]

Since the engine cranks fine and then stumbles as it's about to start, that sounds like it's actually firing off slightly, but won't fully start and sustain itself. Is it possible that the distributor hold down clamp came loose and your timing is off? If your base timing is off enough, that could cause a no start situation I believe.
You say you have fuel delivery and spark, then I think timing is the next thing to confirm. Good luck!

[SJTD]

Sounds likely. Start with the easy checks.

[letank]

If you are getting spark while cranking, but no starting or sputtering, there might be an issue with the ignition switch... not getting spark in the run position -Key released-

Temporarily you can hot wire the coil to bypass the ignition in the run position, you feed a wire directly to the coil positive by using a wire from the battery (+) post or whatever is closer, OK for testing and a short time as the "run" position wire has a resistor to reduce the voltage. It could also be the resistor wire that has a no so good connection to the final running coil wire , about the last 16 to 18" at least on the older FSJ, 85-86 and older.

Otherwise check the carb bowl for gel gas, the ethanol can do wonder in the idle tubes

[Thatguyjacob]

Thank you all again. I fiddled with it the other day to start checking off several things yall have suggested. I did end up swapping the spark plugs and found a bad wire. Unfortunately that wasnt the issue. The plugs were all decent except 3 and 7 were a little rich. I did check the distributor and it was insanely loose and out of time. I mustve accidentally knocked it out of place when i was pulling the power steering pump. I have been trying to tweak it back to where its happy. So far its cranking harder and almost starting significantly more then before but still not starting. Ill keep messing sith the timing to see if i can get it in the sweet spot. Thank you all again. I really appreciate it

[seventynine]

The distributor having been turned like you mentioned would be an issue but usually if you get it close it will start.

I would try pouring some fuel into the carb or more safely some aerosol starter fluid. See if it will run for a bit longer. You might have to add more fuel than you think. Have a fire extinguisher handy. If it will run longer with fuel down the carb you know it’s a fuel problem.

These AMC 360s are notorious for being hard to start and get the pump to prime after running out of gas. When it’s happened to me I’ve always had to dump a bunch of gas in the carb to get it stay running long enough to prime the fuel pump.

The fuel pump could be your culprit or possibly a fuel line leak sucking in air. I’ve had both happen.

You can check the fuel pump to some degree by disconnecting the fuel line after the fuel pump and may be adding a hose into a container then disconnecting the coil wire and cranking it to see if you have fuel flowing.

[Thatguyjacob]

Hello all, it has a new in tank fuel sending unit as well as a new mechanical pump and a clear filter near the carb. Its getting good fuel pressure so im thinking its spark related. Im also wondering if the icm i got is a bad from the box special. Thank you alk for the replies. They are helpful and appreciated

[devildog80]

Suggest you go back to original coil & ICM, as it WAS running before changing the oil.
Did you get the pressure switch plugged back in on the oil pressure line? Check in/around those areas where you did your last task, and make sure a wire did not get bumped loose, or maybe a loose connection is now disconnected but might look like it is ok. Check everything, and try not to go too far into things that "might be this?", as you will chase your tail for weeks. The issue is usually found right near where the last task was done.